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HomeMy WebLinkAboutAPA517- .... .... ,_ I .... Sub task 7 .. 1 0 Phase 1 Final Draft Report Aquatic Studies Program AOF & G I Su Hydro 1982 - - ALASKA POWER AUTHORITY SUSITNA HYDROELECTRIC PROJECT Sub task 7 .. 1 0 Phase 1 Final Draft Report Aquatic Studies Program AOF & G I Su Hydro 1982 by Alaska Department of Fish and Game Susitna Hydro AQuatic Studies 2207 Spenard Road Anchorage. Alaska 99503 tor Acres American Incorporated Uberty Bank Building, Main at Court Buffalo, New York 14202 ARLIS Alaska Resources Library & Information Setvices Anchorage, Alaska (K li?.'S . $ <6 A-h~ f!.O, ~ 17 - ~ !"""' - <0 ('.! cr> ........ "¢ "¢ 0 0 0 LD LD ........ cr> F'~ cr> TABLE OF CONTENTS Page LIST OF FIGURES..................................................... iii L I ST 0 F TABLEs . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . ; X LIST OF PLATES ................ I •••••••• I •••••••••••••••••••••••••••• xi i LIST OF APPENDIX TABLES............................................. xi ii 1. INTRODUCTION ................................................... . 1.1 Background and Objectives ................................ . 1.2 Description of Study Area ................................ . 1.3 Methods .........................................•......... 2. FISHERIES AND HABITAT RELATIONSHIPS ........................... . 2.1 Introduction ............ ·-................................ . 2.2 Salmon Periodicity and Sonar Counts in Relation to Discharge ...•...........•................... 2.3 Percent Incidence of Selected Fish Species in Relation to Discharge ..........•..................... 2.4 Percent Trapping Incidence of Selected Fish Species in Relation to Point Specific Depth and Velocity ......•............................... 2.5 Bering Cisco Spawning Habitat Evaluation .............. ~··· 2.6 Matrixes of Fishery and Physiochemical O.bserva ti ons. ·-......................................... . 2.7 Chum and Sockeye Adult Salmon Observations in Selected Sloughs in Relation to Mainstem Discharge ... ,_ ........................................... . 2.8 Fisheries and Habitat Relationships in the Proposed Impoundment Area .............................. . 2.8.1 Introduction .......•............................... 2.8.2 Water Quality ..................................... . 2.8.3 Substrate .......................................... . 2.8.4 Streamflow and Channel Morphology ................. . 2 .. 8.5 Conclus.ions ........................................ . E-1-1 E-1-1 E-1-7 E-1-8 E-2-1 E-2-1 E-2-1 E-2-12 E-2-24 E-2-30 E-2-35 E-2-43 E-2-49 E-2-49 E-2-49 E-2-57 E-2-59 E-2-61 3. HABITAT RELATIONSHIPS.......................................... E-3-1 3.1 Introduction ............................................. . 3.2 Discharge and Turbidity Relationships .....•............... 3.3 Differences Between Surface Water Temperatures at Matnstem Locations .................................. . 3.4 Diel Surface Water Temperature Fluctuations .............. . 3.5 Selected Slough Habitat Studies .......................... . i E-3-1 E-3-1 E-3-8 E-3-8 E-3-21 TABLE OF CONTENTS (Continued) Page - 3.5.1 Introduction •••....•...............•.....•..•...... 3.5.2 Relationships Between Water Quality in the Mainstem River and Selected Sloughs with Respect to Mainstem Discharge ............. 0 •••••• e •••••••••• D. 1;1 ...... e • .e 3.5.3 Relationships Between Water Quality Characteristics in Study Sloughs .....•...•......• E-3-21 E-3-25 E-3-29 4. PREDICTIVE MODELS.............................................. E-4-1 4.1 I ntroducti o·n .............................................. . 4.2 Stage Analysis ...•.•.....•...••...••.•..•..•......•....... 4.3 Water Temperature Analysis •.•.......•..••...........•..... 4.4 Pre-project and Post-project Flow Comparisons ......•...... E-4-1 E-4-1 E-4-13 E-4-15 5. CONCLUSION..................................................... E-5-1 6. CONTRIBUTORS. . • • • . . • . . • . • . . . . . . . . • . . . . . . • • . . • . • . . . . . . • . . • . . • . . . E-6-1 7. ACKNO\~LEDGEMENTS .........•...•.•.•••.•••.•....•....••.......... E-7-1 8. REFERENCES..................................................... E-8-1 9. APPENDIX....................................................... E-9-1 i i - - - - ~1 ~- .,..., - - - - - LIST OF FIGURES Figure E.1.1 Figure E.l. 2 Figure E.2.1 Figure E.2.2 Figure E. 2. 3 Figure E.2.4 Figure E.2.5 Figure E.2.6 Figure E.2.7 Figure E. 2.8 Figure E.2.9 Susitna River drainage basin ..................... . Drainage map of the Susitna River showing phase 1 study areas ...................... . Hydrograph (discharge vs. time) for May-September 1981 for the Susitna River at Gold Creek, Sunshine, and Susitna stations and for the Yentna River near Susitna Station (USGS 1981) .............................................. . Provisional periodicity for the various life phases of chinook salmon as it relates to discharge of the Susitna River (USGS 1981} ........................ . Provisional periodicity for the various life phases of coho salmon as it relates to discharge of the Susitna River (USGS 1981} ........................ . Provisional periodicity for the various life phases of chum salmon as it relates to discharge of the Susitna River (USGS 1981) ........................ . Provisional periodicity for the .various life phases of pink salmon as it relates to discharge of the Susitna River (USGS 1981) ........•................ Provisional periodicity for the various life phases of sockeye salmon as it relates to discharge of the Susitna River (USGS 1981) .............•.........•. Sonar counts of adult chinook salmon at each AA sonar site as compared to discharge of the Susitna River (adapted from USGS 1981 and ADF&G 1981a) .................. . Sonar counts of adult coho salmon at each AA sonar site as compared to discharge of the Susitna River (adapted from USGS 1981 and ADF&G 1981a) ................•.. Sonar counts of adult chum salmon at each AA sonar site as compared to discharge of the Susitna River (adapted from USGS 1981 and Jl..DF&G 1981a) ................. .. iii Page E-1-2 E-1-4 E-2-6 E-2-7 E-2-8 E-2-9 E-2-10 E-2-11 E-2-13 E-2-14 E-2-15 LIST OF FIGURES (Continued) F i g u re E . 2 . 1 0 Figure E. 2 .11 Figure E.2.12 Figure E. 2.13 Figure E.2.14 Figure E.2.15 Figure E.2.16 Figure E.2.17 Sonar counts of adult pink salmon at each AA sonar site as compared to discharge of the Susitna River (adapted from USGS 1981 and ADF&G 1981a) ................•.. Sonar counts of adult sockeye salmon at each AA sonar site as compared to discharge of the Susitna River (adapted from USGS 1981 and ADF&G 1981a) ...............•... Changes in the percent incidence of burbot catch in the Talkeetna to Devil Canyon reach of the Susitna River as it relates to mainstem discharge of the Susitna River at Gold Creek (adapted from USGS 1981 and ADF&G 1981f) ........................•.... Changes in the percent incidence of rainbow trout catch in the Talkeetna to Devil Canyon reach of the Susitna River as it relates to mainstem discharge of the Susitna River at Gold Creek (adapted from USGS 1981 and ADF&G 1981 f) ....•....•.............•..... Changes in the percent incidence of chinook salmon fry {age 0+) catch in the Talkeetna to Devil Canyon reach of the Susitna River as it relates to mainstem discharge of the Susitna River at Gold Creek (adapted from USGS 1981 and AOF&G 1981f) ......... . Trapping incidence data for juvenile chinook salmon versus point specific depth and mean column water velocity data collected in minnow traps at habitat locations, 1981 (AOF&G 1981c and d) .............................................. . Trapping incidence data for rainbow trout versus point specific depth and mean column water velocity data collected by trot lines at habitat locations, 1981 (ADF&G 198lc and f) .............. . Bering cisco spawning area on the Susitna River at Sunshine, R.M. 78.0 to R.M. 79.0, October 13, 1981 (adapted from ADF&G 1981 f) ....................... . iv ~' E-2-16 - E-2-17 - E-2-18 - E-2-19 - E-2-20 E-2-27 - E-2-28 E-2-32 - - - - LIST OF FIGURES (Continued) Figure E.2.18 Figure E.2.19 Figure E.2.20 Figure E.2.21 Figure E.3.1 Figure E.3.2 Figure E.3.3 Figure E.3.4 Figure E.3.5 Bering cisco spawning area on the Susitna River at Montana Creek (Sites 1 and 2), R.M. 76.0 to R.M. 77.5, October 15, 1981 (adapted from ADF&G 1981f) .•...•.•..•.•.•......... Bering cisco spawning area on the Susitna River at mainstem West Bank R.M. 75.0 October 13, 1981 (adapted from ADF&G 1981f) .......................• Locatinn of selected habitat slough sites along the Susitna River between Talkeetna and Portage Creek (adapted from ADF&G 1981a) ................................ . Sampling design for identifying habitat location and miscellaneous fish habitat study sites in the Impoundment study reach tributaries .•.....•.•.•.......•....... Mainstem turbidity (Talkeetna to Portage Creek reach) versus mainstem discharge of the Susitna River at Gold Creek (adapted from ADF&G 1981c and USGS 1981) .................................... . Slough turbidity (Talkeetna to Portage Creek reach) versus mainstem discharge of the Susitna River at Gold Creek (adapted from ADF&G 1981c and USGS 1981) ......•....•.•.............•.......• Mainstem turbidity (downstream of Talkeetna) versus mainstem discharge of the Susitna River at Sunshine (adapted from ADF&G 198lc and USGS 1981 ) ............................................ . Slough turbidity (downstream of Talkeetna) versus mainstem discharge of the Susitna River at Sunshine (adapted from ADF&G 1981c and USGS 1981 ) ............................................. . Mainstem turbidity of the Susitna River as a function of time at the following sites: below Deshka River (R.M. 31.0); above the Parks Highway Bridge (R.M. 84.0); above Gold Creek (R.M. 136.9) and above Jay Creek ( R. M. 203. 9) ....................................... . v E-2-33 E-2-34 E-2-46 E-2-50 E-3-2 E-3-3 E-3-4 E-3-5 E-3-7 LIST OF FIGURES (Continued) Figure E.3.6 Figure E.3.7 Figure E.3.8 Figure E.3.9 Figure E.3.10 Figure E.3.11 Figure E.3.12 Figure E.3.13 Figure E.3.14 Figure E.3.15 Figure E.3.16 Mean daily mainstem surface water temperature profile for the Susitna River for June 20, 1981 .......•................... Mean daily mainstem surface water temperature profile for the Susitna River for June 30, 1981 ..........................• Mean daily mainstem surface water temperature profile for the Susitna River for July 17, 1981 ........••................. Mean daily mainstem surface water temperature profile for the Susitna River for July 29, 1981 .............•....•........ Mean daily mainstem surface water temperature profile for the Susitna River for August 15, 1981. ...................... .. Mean daily mainstem surface water temperature profile for the Susitna River for August 25, 1981. ...................... .. Mean daily mainstem surface water temperature profile for the Susitna River for September 8 and 11, 1981 ......••........ Mean daily mainstem surface water temperature profile for the Susitna River for September 28, 1981 .•...•....•....•...•.. Comparison of weekly diel surface water temperature variations in Slough 21 and the mainstem Susitna River at Portage Creek (adapted from ADF&G 1981c) •••.................•......•....• Comparision of weekly diel surface water temperature variations in Montana Creek and the mainstem Susitna River at the Parks Highway Bridge (adapted from ADF&G 1981c) ........•........ Susitna River gradient between Tal- keetna and Portage Creek showing positions of selected habitat study sloughs (adapted from R&M 1982b) .................. . vi E-3-10 -· E-3-11 -E-3-12 - E-3-13 - E-3-14 - E-3-15 E-3-16 E-3-17 - E-3-18 E-3-19 E-3-22 - - - - - LIST OF FIGURES (Continued) Figure E.3.17 Figure E.3.18 Figure E.4.1 Figure E.4.2 Figure E.4.3 Figure, E. 4. 4 Figure £.4.5 Figure E.4.6 Figure E.4.7 Planimetric map of Slough 8A ....•.....•..•.•...... Planimetric map of Slough 9 ...•................... Comparison of the observed stage/ discharge relationship (ADF&G 1981c) to the predicted WSEL/discharge relationship (R&M 1982a, b) for the Susitna River at Talkeetna Base Camp (R.M. 101.0) ....•..............•............. Comparison of the observed stage/ discharge relationship (ADF&G 1981c) to the predicted WSEL/discharge relationship (R&M 1982a, b) for the Susitna River at the Mainstem 2 habitat 1 ocation (R.M. 114.4) ................... .. Comparison of the observed stage/ discharge relationship (ADF&G 1981c) to the predicted WSEL/discharge relationship (R&M 1982a, b) for the Susitna River at the Curry Fishwheel Camp (R.M. 120.7) ................................. . Comparison of the observed stage/ discharge relationship (ADF&G 1981c) to the predicted WSEL/discharge relationship (R&M 1982a, b) for the Susitna River at the Curry habitat location (R.M. 120.7) ..........•......•........... Comparison of the observed stage/ discharge relationship (ADF&G 1981c) to the predicted WSEL/discharge relationship (R&M 1982a, b) for the Susitna River at the Mainstem Susitna-Inside Bend habitat location Page E-3-23 E-3-24 E-4-5 E-4-6 E-4-7 E-4-8 (R.M. 136.9) ...... _......... ..... .... .......... ... .. E-4-9 Comparison of the observed stage/ discharge relationship (ADF&G 1981c) to the predicted WSEL/discharge relationship (R&M 1982a, b) for the Susitna River at Slough 168 (R.M. 138.0) ......... . Comparison of the observed stage/ discharge relationship (ADF&G 1981c) to the predicted WSEL/discharge relationship (R&M 1982a, b) for the Susitna River at Slough 19 (R.M. 140.0) .......•... vii E-4-10 E-4-11 """' LIST OF FIGURES (Continued) Page - Figure E.4.8 Comparison of the observed stage/ discharge relationship (ADF&G 1981c) to the predicted WSEL/discharge relationship (R&M 1982a, b) for the Susitna River at the Mainstem Susitna - Island habitat location (R.M. 146 . 9 ) .............. E-4-12 - Figure E. 4 . 9 Mean monthly pre-project (USGS 1977, 1978a, 1978b, 1979) and predicted ~~ (R&M 1982a, b) post-project power (Case A scenario) discharge (cfs) of the Susitna River at Gold Creek for the period 1950-1978 .......•.................. E-4-20 -· Figure E.4.10 Mean monthly pre-project (USGS 1977, 1978a, 1978b, 1979) and predicted -(R&M 1982a) post-project power (Case A scenario) discharge (cfs) of the Susitna River at Sunshine for the period 1950-1978 ...•....•................. E-4-21 - Figure E.4 .11 Mean monthly pre-project (USGS 1977, 1978a, 1978b, 1979) and predicted -(R&M 1982a) post-project power (Case A scenario) discharge (cfs) of the Susitna River at Susitna Station for the period 1950-1978 ............•..... E-4-22 Figure E.4.12 Mean monthly pre-project (USGS 1978a) and predicted (R&M 1982a) post--project power (Case A scenario) discharge (cfs) of the Susitna River at Gold Creek for the years 1950-1964 and pro-·~ visional periodicity of adult salmon spawning and passage ........•..........•... E-4-23 Figure E.4.13 Mean monthly pre-project (USGS 1977, 1978a, 1978b, 1979) and predicted (R&M 1982a) post-project power (Case A scenario) discharge (cfs) of the Susitna River at Gold Creek for the years 1965-1978 and pro- visional periodicity of adult salmon .,., spawning and passage •.......................•.•... E-4-24 - - viii LIST OF TABLES Table E.2.1 - Table E. 2. 2 Table E.2.3 Table E.2.4 Table E.2.5 Table E.2.6 - Table E.2. 7 - Provisional USGS discharge data (cfs) for the Susitna River at Gold Creek, Sunshine, and Susitna Station and for the Yentna River near Susitna Station for the period of May -September, 1981 (USGS 1981) ..............•.........•..•....•. Bering cisco spawning site evaluation on the Susitna River, October 10-13, 1981 {adapted from ADF&G 1981c, f) •............... Matrix of observed fish species and physiochemical parameters for habitat locations in the Yentna study reach of the Susitna River, May-September, 1981 (adapted from ADF&G 1981a, c, d, f, g) .......................................... . Matrix of observed fish species and physiochemical parameters for habitat locations in the Sunshine study reach of the Susitna River, May-September, 1981 (adapted from ADF&G 1981a, c, d, f, g) ............ ;.. ..... -......................... . Matrix of observed fish species and physiochemical parameters for habitat locations in the Talkeetna study reach of the Susitna River, May-September, 1981 (adapted from ADF&G 1981a, c, d, f, g) ......................................... . Matrix of observed fish species and physiochemical parameters for habitat locations in the Gold Creek study reach of the Susitna River, May-September, 1981 (adapted from ADF&G 1981a, c, d, f, g) ................................ ~·········· Matrix of observed fish species and phys i ochemi ca 1 parameters for habitat locations in the Impoundment study reach of the Susitna River, May-September, 1981 (adapted from ADF&G 1981a, c, d, f, g) •••••• ·-···· ................................ . ix E-2-2 E-2-31 E-2-36 E-2-37 E-2-38 E-2-39 E-2-40 LIST OF TABLES (Continued) Table E.2.8 Table E.2.9 Table E.2.10 Table E.2.11 Table E.2 .12 Table E.2.13 Table E.3.1 Table E.4.1 Matrix of observed fish species and physiochemical parameters for the selected habitat slough study sites of the Susitna River, May-September, 1981 (adapted from ADF&G 1981a, c, d,f,g) ........................................... e Comparison of adult sockeye and chum salmon escapement counts for Sloughs SA, 9, 98, 19, and 21 (ADF&G 1981a) to Susitna River discharge data (cfs) at Gold Creek (USGS 1981) •.•..••••.•..•..•..•••••. Arctic grayling hook and line catch and effort at habitat location sites in the lower mile of each tributary in the Impoundment study area, 1981 (adapted from ADF&G 198lg) .•.•••.....•..•••....••• Arctic grayling hook and line catch and effort at miscellaneous fish habitat sites between the mouth and proposed impoundment elevations (PIE) at each tributary in the Impounpment study area, 1981 (adapted from ADF&G 1981g) •..•..•..•.••....•••.•.• Arctic grayling hook and line total catch by tributary between the mouth and proposed impoundment elevations (PIE) and month in the Impoundment study area, 1981 (adapted from ADF&G 198lg) .................... ····~··············· ... . Arctic grayling population estimates for tributaries in the Impoundment study area, 1981 (adapted from ADF&G 1981 g ) ............................................. . Mainstem Susitna River surface water temperatures, oc (ADF&G 1981c) for various sites used in developing Figures E.3.6-E.3.13, 1981 .............•...•.••• Comparison of observed stage (ADF&G 1981c) to predicted water surface elevation (WSEL) data (R&M 1982a, b) at various Susitna River discharges, cfs (USGS 1981), used in developing Figures E .4 .1 -E.4 .8 •••.•••.••••..•......•••••.•• X - E-2-42 E-2-44 - E-2-51 E-2-52 - E-2-53 - -E-2-54 - E-3-9 - E-4-3 - .- - - LIST OF TABLES (Continued) Table E.4.2 Table E.4.3 Table E.4.4 Tab 1 e E.4 .5 Comparison of observed mean monthly surface water temperatures, °C (ADF&G 1981c), to predicted mean monthly surface water temperatures (Acres 1982) for the Susitna River ..........•............ Case A scenario mean monthly post- project power discharge (cfs) for the Susitna River at Gold Creek (R&M 1982a) for the years 1950- 1978. • • • • a • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Mean monthly pre-project discharge (cfs) for the Susitna River at Gold Creek (USGS 1977, 1978a, 1978b, 1979) for the years 1950-1978 .•......•..•...••..•....•.. Comparison of mean monthly pre-project (USGS 1977, 1978a, 1978b, 1979) and predicted post-project power discharges (cfs) (R&M 1982a), for the Susitna River at Gold Creek, Sunshine and Susitna Station over the period of 1950-1978 ....................................... ·-. xi E-4-14 E-4-16 E-4-17 E-4-19 LIST OF PLATES Plate 1 Plate 2 Plate 3 Plate 4 Plate 5 Plate 6 Plate 7 Plate 8 Plate 9 Plate 10 - - Gill net set at Slough West Bank (R.~1. 65.6) ...................................... . Baited fry trap set at Whiskers Creek .......•..... Seining Jay Creek Slough .....•.................... Electrofishing in lower Jay Creek .........•....... Arctic grayling with Flay anchor tag .............................................. . Confluence of Susitna River and Kosina Creek in the Impoundment study reach, showing mixing of clear and turbid waters ..••...••...•....•..•....•. Mouth of Slough 9 (mainstem Susitna discharge 7,920 cfs), October 14, 1981 ...•....•.••.•.•..••...........••. View of head of Slough 168 (mainstem Susitna River discharge 14,500 cfs), September 9, 1981 ................................ . View of mouth of Slough 168 (mainstem Susitna River discharge 14,500 cfs), September 9, 1981 ....•..•.•.....•.•.•...........•. Aerial view of Slough 19 (mainstem Susitna discharge 7,440 cfs), October 15, 1981 .•...•......•......•....•.•....... xii E-2-22 E-2-25 E-2-56 E-2-58 E-2 -60 E-2-63 E-3-26 E-3-28 E-3-30 E-3-32 - - - LIST OF APPENDIX TABLES Table EA-1 Table EA-2 Table EA-3 i Table EA-4 Table EA-5 Table EA-6 Table EA-7 Table EA-8 Table EA-9 Table EA-10 Table EA-11 Table EA-12 Table EA-13 Table EA-14 Head pin elevations in Slough 8A surveyed October 7-10, 1981 ................................................... I •••• EA-2 Cross section elevations in transect 1 (first head) of Slough 8A, surveyed October 10, 1981. Transect was dewatered .........................................•........ EA-3 Cross section elevations in transect 2 (second head) of Slough 8A, surveyed October 10, 1981. Transect was dewatered ........•...•..................................... EA-4 Cross section elevations in transect 3 (third head) of Slough 8A, surveyed October 10, 1981. Transect was dewatered ...•.............................................. EA-5 Cross section elevations in transect 4 (fourth head) of Slough 8A, surveyed October 10, 1981. Transect was dew a tered.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . • . . . . . . . . . . . . EA-6 Cross section elevations in transect 5 (fifth head) of Slough 8A, surveyed October 11, 1981. Transect was dewatered ................................................... EA-7 Cross section elevations in transect 6 (sixth head) of Slough 8A, surveyed October 10, 1981. Transect was dewatered ..........................•....................... EA-9 Cross section elevations in transect 7 (mouth) of Slough 8A, surveyed October 10, 1981. ............................. EA-10 Head pin elevations in Slough 9, surveyed October 12-14, 1981. ................................•...................... EA-11 Cross section elevations in transect 1 (head) of Slough 9, surveyed October 14, 1981. Transect was dewatered ......... EA-12 Cross section elevations in transect 2 of Slough 9, surveyed October 14, 1981. Transect was dewatered •........ EA-14 Cross section elevations in transect 3 of Slough 9, surveyed October 14, 1981. ................................. EA-15 Cross section elevations in transect 4 of Slough 9, surveyed October 14, 1981.................................. EA-16 Cross section elevations in transect 5 (mouth) of Slough 9, surveyed October 14, 1981 ............................... EA-17 xiii - LIST OF APPENDIX TABLES (Continued) Table EA-15 Head pin elevations in Slough 168, surveyed September 9, 10, 16,and 17, 1981 ........................................ EA-18 -Table EA-16 Cross section elevations in transect 1 (mouth) of Slough 168, surveyed September 9, 1981. ........................... EA-20 Table EA-17 Cross section elevations in transect 2 of Slough 168, surveyed September 17, 1981. ............................... EA-21 Table EA-18 Cross section elevations in transect 3 of Slough 168, -surveyed September 16, 1981. ............................... EA-22 Table EA-19 Cross section elevations in transect 4 of Slough 168, surveyed September 16, 1981. ............................... EA-23 Table EA-20 Cross section elevations in transect 5 of Slough 168, surveyed September 16, 1981. ............................... EA-24 - Table EA-21 Cross section elevations in transect 6 of Slough 168, surveyed September 16, 1981 ................................ EA-25 - Table EA-22 Cross section elevations in transect 7 of Slough 168, surveyed September 16, 1981 ....•...................•....•.. EA-26 Table EA-23 Cross section elevations in transect 8 of Slough 168, surveyed on September 16, 1981. ............................ EA-27 Table EA-24 Cross section elevations in transect 9 of Slough 168, surveyed on September 16, 1981. ............................ EA-28 Table EA-25 Cross section elevations in transect 10 of Slough 168, surveyed September 16, 1981. ............................... EA-29 Table EA-26 Cross section elevations in transect 11 of Slough 168, surveyed September 16, 1981 ................................ EA-30 Table EA-27 Cross section elevations in transect 12 of Slough 168, surveyed September 16, 1981. ............................... EA-31 1able EA-28 Cross section elevations in transect 13 of Slough 168, surveyed September 10, 1981 ...................•............ EA-32 - Table EA-29 Cross section elevations in transect 14 of Slough 168, surveyed September 10, 1981. ............................... EA-33 Table EA-30 Cross section elevations in transect 15 of Slough 168, surveyed September 10, 1981 .....•.......................... EA-34 xiv LIST OF APPENDIX TABLES (Continued) - Table EA-31 Cross section elevations in transect 16 of Slough 168, surveyed September 10, 1981. ............................... EA-35 Table EA-32 Cross section elevations in transect 17 (head) of Slough 168, surveyed September 9, 1981. Transect was dewatered ... EA-36 Table EA-33 Head pin elevations in Slough 19, surveyed September 25, 1981 ....................•.................................. EA-37 Table EA-34 Cross section elevations in transect 1 {mouth) of Slough 19. surveyed September 26, 1981. ........................... EA-38 Table EA-35 Cross section elevations in transect 2 of Slough 19, surveyed September 26, 1981. ............................... EA-39 Table EA-36 Cross section elevations in transect 3 of Slough 19, surveyed September 26, 1981. ............................... EA-40 Table EA-37 Cross section elevations in transect 4 of Slough 19, --surveyed September 26, 1981................................ EA-41 Table EA-38 Cross section elevations in transect 5 of Slough 19, '~ surveyed September 26, 1981. ............................... EA-42 Table EA-39 Cross section elevations in transect 6 of Slough 19, surveyed September 26, 1981 ................................ EA-43 Table EA-40 Cross section elevations in transect 7 of Slough 19, surveyed September 26, 1981................................ EA-44 Table EA-41 Cross section elevations in transect 8 of Slough 19, surveyed September 26, 1981. Transect was dewatered ....... EA-45 Table EA-42 Cross section elevations in transect 9 of Slough 19, surveyed September 26, 1981 ................................ EA-46 Table EA-43 Cross section elevations in transect 10 {head) of Slough 19, surveyed September 26, 1981. .................... EA-47 Table EA-44 Head pin elevations in Slough 21, surveyed August 24-27, 1981 ..•...•......•.............•.................... EA-48 Table EA-45 Cross section elevations in transect 1 {head) of Slough 21, surveyed September 5, 1981. Transect was dewatered .... EA-50 Table EA-46 Cross section elevations in transect 1-A (head) of Slough 21, surveyed September 5, 1981. Transect was dewatered .... EA-51 XV LIST OF APPENDIX TABLES (Continued) - Table EA-47 Cross section elevations in transect 1-B of Slough 21, surveyed September 5, 1981. Transect was dewatered ........ EA-52 Table EA-48 Cross section elevations in transect 2 of Slough 21, surveyed September 5, 1981. Transect was dewatered ........ EA-53 Table EA-49 Cross section elevations in transect 2-A of Slough 21, surveyed September 5, 1981 ................................. EA-54 Table EA-50 Cross section elevations in transect 3 of Slough 21, -surveyed September 5, 1981 ...................... ; .......... EA-55 Table EA-51 Cross section elevations in transect 4 of Slough 21, surveyed September 5, 1981 ................................. EA-56 Table EA-52 Cross section elevations in transect 5 of Slough 21, surveyed August 25, 1981................................... EA-57 Table EA-53 Cross section elevations in transect 5-A of Slough 21, surveyed August 25, 1981. ....••...................•..••...• EA-58 Table EA-54 Cross-section elevations in transect 6 of Slough 21, surveyed August 25, 1981 .................•................. EA-59 Table EA-55 Cross section elevations in transect 7 of Slough 21. surveyed August 25, 1981. .................................. EA-60 Table EA-56 Cross section elevations in transect 8 of Slough 21, surveyed August 25, 1981 ................................... EA-61 Table EA-57 Cross section elevations in transect 9 of Slough 21, surveyed August 25, 1981. .................................. EA-62 Table EA-58 Cross section elevations in transect 10 of Slough 21, surveyed August 25, 1981. .................................. EA-63 Table EA-59 Cross section elevations in transect 11 of Slough 21, surveyed August 25, 1981 •..............•........•.......... EA-64 Table EA-60 Cross section elevations in transect 12 of Slough 21, surveyed August 25, 1981. .................................. EA-65 Table EA-61 Cross section elevations in transect 13 of Slough 21, surveyed August 25, 1981 ..............................•..•. EA-66 - xvi - -i - l. lNTRODUCfl ON - 1. INTRODUCTION 1.1 Background and Objectives This report highlights and compares selected physical, chemical, and biological data contained in a series of reports evaluating the feasibility of the Susitna Hydroelectric (Su-Hydro) project. The feasibility study reports were submitted to Acres American Inc. {Acres) by the Alaska Department of Fish and Game {ADF&G) Su-Hydro Aquatic Studies Team and other project i nvesti- gators. Acres was contracted in 1979 by the Alaska Power Authority (APA) to assess the feasibility of the proposed two dam Susitna Hydroelectric project. The feasibility assessment includes a five year, two-phase fish ecology study program. Objectives established for this program are (Acres 1980): 1. describe the fishery and aquatic habitat resources of the Sus i tna River (Figure E.1.1); 2. 3. assess the impacts of development and operation of the Su-Hydro project on these resources; and propose mitigation measures to minimize adverse impacts. The ADF&G Aquatic Studies Team was contracted by the APA under a Reimbursable Services Agreement to begin the collection program directed at meeting the first objective. The second and third objectives were subcontracted to Terrestrial Environmental Specialists (TES) by Acres in 1980. E-1-1 J Map Area ;/ , ,., / .,..,...------.... / I I I I I I I I I I \ \ ' ......... ........ ,, ', ........ ..... , ....... ' ' \ / I / / I I I I I I ..-' / Figure E.l.l. Susitna River drainage basin. J / I I I I I / / ', ' ' ' ' ........ ..... _ ---.... ' ' \ \ ' ' ' I I I I I I I I I I I // fl'-..... / / ...... ______ ., Drainage Boundary .._ __ , I I I I I ....., __ ... - - The ADF&G data collection program (designed to meet objective one) was initiated in November 1980. The ice-covered (November 1980-May 1981) portion of the field data collection program was subdivided into two sections: 1) Resident and Juvenile Anadromous Fish Studies (RJ), and Aquatic Habitat and Instream Flow Studies (AH). During the open water field season (June 1981-0ctober 1981), the program was subdivided into three sections: Adult Anadromous Fish Studies {AA), RJ, and AH. Specific objectives of the AA, RJ, and AH sections based on a five year study program are: 1. determine the seasonal distribution and relative abundance of adult anadromous fish populations produced within the study area (Figure E.1.2) (AA); 2. determine the seasonal distribution and relative abundance of selected resident and juvenile anadromous fish populations within the study area (RJ); and 3. characterize the seasonal habitat requirements of selected anadromous and resident fish species within the study area {AH). Following preliminary data reduction, field data collected by the ADF&G during 1980-1981 were summarized in a series of six reports (ADF&G 1981a, b, c, d, f, g). Progress towards meeting the first ADF&G aquatic study objective included the collection of escapement data which gave a description of the five adult salmon populations which returned to the Susitna River during an odd-year E-1-3 fTl I ....... I ..p:. ~ N ' / I I I I I I I I I I l \ \ ,- SUSITNA RIVER DRAINAGE BASIN ~ 1981 Open Water Study Area ~ 1980-1981 Winter Study Area .---i 1 1 River Drainage Study Area ___ ... Figure E.1.2. Drainage map of the Susitna River showing phase 1 study areas. - -· - - salmon run (ADF&G 1981a and b)*. AA field studies in 1981 did not include an assessment of the seasona 1 distribution and relative abundance of eul achon (Thaleichthys pacificus) or Bering cisco (Coregonus laurettae). Bering cisco, not previously known to utilize this system, were observed spa\·-ming in the Susitna River during 1981 (ADF&G 1981f). Progress on the second aquatic study objective included describing the distribution and abundance of selected resident and juvenile anadromous fish observed over one year (ADF&G 1981d, f, g). Although some of this information was quite detailed [e.g. information on Arctic grayling (Thymallus arcticus) populations in the proposed impoundment area], other data were quite sparse and did not permit definitive determinations of distribution or abundance. For example, the extent, location, and duration of fresh-water rearing of juvenile sockeye populations is largely unknown. Progress towards addressing the third aquatic study objective was limited to a first attempt at describing the aquatic resources of selected areas in the Susitna River and characterizing the relationships between the fishery resources and their aquatic habitats. The description of the aquatic habitat relationships studied by AH in 1980-1981 are summarized in the AH report (ADF&G 1981c). To accomplish the three aquatic study objectives, additional information will be required through succeeding years. Relationships between the fishery * Salmon runs vary on a year to year basis (e.g. pink salmon escapement is usually highest during even years). E-1-5 resources and aquatic habitat which can presently be identified are preliminary and are limited to those fish species/life stages and habitat areas in which data on both fish distribution/abundance and aquatic habitat characteristics are most complete. These relationships were not reported in detail in the six ADF&G reports. Therefore, one of the objectives for preparing this report is to present a better description of these fishery/aquatic habitat relationships. Accordingly, the first chapter of this report describes those fishery/aquatic habitat relationships which can be developed given existing information. A second objective of this report is to expand the discussions describing the relationships between individual physical and chemical {physiochemical) aquatic habitat parameters contained in the earlier AH report (ADF&G 198lc). Accardi ngly, the second chapter describes the relationships observed between individual aquatic habitat parameters (eg. temperature and turbidity) and discharge. These are some of the obvious relationships which can be affected by the installation and operation of the proposed dams. A third objective of this report is to discuss some of the preliminary physical computer mode1s which have been developed by Acres and their subcontractors to predict postproject temperature and stage/discharge relationships of the Susitna River downstream of the two dams. Comparisons between predicted characteristics are and observed included in stage, temperature, this chapter. Predicted and and discharge observed discharge characteristics are also related to provisional periodicity data on E-1-6 - ~\ "''" - - r- 1 adult anadromous salmon spawning activity. These data could also be used to refine the existing models and identify additional data collection require- ments. It should be emphasized that this report should not be interpreted as an impact analysis : a more thorough analysis of the six previously produced ADF&G reports (ADF&G 198la, b, c, d, f, and g), this report, and other documents (e.g. ADF&G 1974, 1976, 1977, 1978; ADNR 1977, 1979; R&M 1982a) by a designated contractor is required. Also, note that the analysis and summarization of information contained in this report is ~ intended to substitute for the six individual ADF&G aquatic study summary reports. 1.2 Description of Study Area The study area was 1 imited to the mainstem Susitna River and the mouths of major tributaries (Figures E.1.1, E.1.2). The Susitna River is approximately 275 miles long from its sources in the Alaska Mountain Range to its point of discharge into Cook Inlet. Its drainage encompasses an area of 19,400 square miles. The mainstem and major tributaries of the Susitna River, including the Chulitna, Talkeetna and Yentna Rivers, originate in glaciers and carry a heavy load of glacial flour during the ice-free months (approximately May through October). There are many smaller tributaries which are perennially clear. Specific descriptions of the study sites and additional details are presented in the AA, AH and RJ reports (ADF&G 1981a, b, c, d, f, g). E-1 -7 Anadromous fish species inhabiting the Susitna River include eulachon, Bering cisco, and five of the six species of Pacific salmon (chinook, Oncorhynchus tschawytscha; coho, Q. kisutch; chum, Q. keta; sockeye, Q. nerka; and pink, Q. gorbuscha). With the exception of sockeye salmon, the majority of upper Cook Inlet salmon production occurs within the drainage (ADF&G 198lb). Some of the important resident species found in the Susitna River drainage include Arctic grayling, rainbow trout (Salmo gairdneri), lake trout (Salvelinus namaycush), burbot (Lata lata), Dolly varden (Salvelinus malma), and round whitefish (Prosopium cylindraceum). The principal impacts of the proposed Susitna Hydroelectric project on fish species will likely result from changes in the natural flow regimes of the river; of particular concern are: modification of seasonal instream flows*, increased turbidity levels during winter months, and variation of thennal and chemical parameters. The feasibility studies will ultimately provide the basis for quantifying these impacts and evaluating mitigation options. 1.3 Methods Data collection methods are discussed in the ADF&G Procedures Manual (ADF&G 198le) and AH, RJ and AA subject reports (ADF&G 1981a, b, c, d, f, g). Data analysis techniques utilized in this report are discussed in the respective sections. * The quantity or flow of water which is present in a river or stream at a given location and time constitutes the instream flow. E-1-8 - - - - - - ~- - 2. FISHERIES PI·ID HABITAT RELATHliSHIPS -i r I ,..,. I I - - 2. FISHERIES AND HABITAT RELATIONSHIPS 2.1 Introduction This chapter describes several fishery/aquatic habitat relationships which can presently be developed. These relationships are limited to those areas in which data on both fish di !;itribution/abundance and aquatic habitat characteristics are most complete. It should be noted, however, that infonnation en all species and their corresponding habitats in the Susitna River is still in a preliminary stage of development and analysis. 2.2 Salmon Periodicity and Sonar Counts in Relation to Discharge Changes in discharge can influence fish behavior and activities (Hynes 1970; Hocutt et al. 1980). Provisional discharge data (Table £.2.1) for the Susitna River at Gold Creek, Sunshine (Parks Highway Bridge), arid Susitna Station gaging sites, and the Yentna River gaging site (T.R.M. 10)*, for the period May through September 1981, are presented as hydrographs (discharge versus time plots) in Figure E.l.1 Figures £.2.2 -£.2.6 combine the Susitna River hydrographs with provisional periodicity charts illustrating the known seasonal timing of spawning, incubation, rearing, and passage for each of the five species of salmon inhabiting the Susitna River in two reaches downstream of Devil Canyon (R.M. 0 -R.M. 84 and R.M. 84 -R.M. 149}.** The periodicity charts are based on a combination of the data presented in the AA and RJ subject reports (ADF&G * ** Tributary river mile. Susitna river mile. E-2-1 ~~ Table E.2.1. Provisional USGS discharge data (cfs) for the Susitna River at Gold Creek, Sunshine, and Susitna Station and for the Yentna River near Susitna Station for the period of May -September, 1981 (USGS 1981). Susitna River Yentna River Date Gold Creek Sunshine Susitna Susitna 810501 28,000 10,000 810502 35,000 10,000 810503 45,000 11 ,000 810504 60,000 12,000 810505 70,000 14,000 810506 70,000 17,000 810507 75,000 25,000 ""'' 810508 35,300 80,000 45,000 810509 56,600 95,000 50,000 810510 24,000 49,300 100,000 52,000 """ 810511 22,400 46,000 95,000 52,000 810512 20,000 42,800 85,000 50,000 810513 18,400 41,000 80,000 45,000 810514 19,100 41,000 80,000 . 40,000 """ 810515 21,800 44,700 85,000 40,000 810516 21,900 45,600 95,000 45,000 810517 20,700 44,600 110,000 45,000 -810518 19,100 42,000 100,000 50,000 810519 18,200 41,100 100,000 54,000 810520 17,000 39,400 100,000 58,100 810521 14,600 37,000 99,800 60,500 ~· 810522 12,700 34,000 91,100 50,900 810523 11 ,300 31,400 83,200 44,500 810524 10,800 32,700 '76 ,400 40,500 810525 11 '700 31,800 75,100 39,700 810526 13 ,300 34,500 78,700 43,300 810527 14,600 37,000 86,900 49,500 810528 16,400 40,500 94,900 52,900 810529 19,900 46,700 102,000 54,100 810530 20,500 48,400 105,000 55,700 810531 22,400 51,600 110,000 58,900 -810601 27,600 62,400 120,000 62,200 810602 23,400 57,200 122,000 60,900 810603 19,000 48,000 112,000 57,000 810604 17,000 44,800 103,000 53,200 - 810605 17,000 43,300 98,900 49,600 810606 19,100 46,600 98,000 48,000 810607 18,000 45,700 94,900 43,900 ~ 810608 15,800 43,100 94,700 45,300 810609 16,700 44,300 94,300 46,600 810610 18,300 47,200 99,500 49,400 ~ 810611 16,200 43,700 97,200 44,500 810612 14,800 41,200 90,200 42,700 810613 14,000 40,200 89,000 42,900 ---Data unavailable. E-2-2 Table E.2.1 (Continued). Susitna River Yentna River !""" Date Go1d Creel< Sunshine Susitna Susitna 810614 14,200 40,900 89,700 44,600 810615 15,300 42,000 93,000 47,900 810616 18,200 47,400 98,800 50,900 810617 18,300 50,700 105,000 52,700 810618 17,400 51,100 113,000 58,600 810619 17,200 52,700 117,000 63,000 810620 16,600 53,100 121,000 66,600 810621 17,000 53,500 122,000 67,200 810622 16,800 53,600 122,000 65,500 810623 16,500 51,400 117,000 61,000 810624 16,600 51,900 116,000 60,500 810625 17,100 51,600 117,000 61,400 -810626 17,200 50,000 118,000 61,500 810627 18,000 49,000 117,000 60,500 810628 23,000 52,000 119,000 61,100 810629 24,100 56,000 127,000 57,900 810630 24,000 56,000 132,000 57,800 810701 21,800 51,000 131,000 49,200 810702 18,800 46,000 115,000 41,600 810703 16,200 43,000 103,000 38,500 810704 14,600 42,000 95,200 37,700 810705 13,900 42,000 91,600 38,300 810706 14,600 46,000 89,800 39,200 810707 16,900 50,000 92,600 42,700 810708 24,800 56,000 98,300 45,500 """' 810709 24,900 68,000 108,000 43,400 810710 36,300 86,000 119,000 51,600 810711 49,100 100,000 183,000 76,700 810712 58,200 130,000 198,000 78,000 810713 49,300 115,000 189,000 68,300 810714 38,600 100,000 176,000 67,500 810715 32,200 99,000 174,000 78,400 810716 34,000 98,700 189,000 95,100 810717 38,400 98,500 200,000 95,300 810718 43,000 97,100 194,000 85,900 810719 43,500 97,100 189,000 79,000 ,_ 810720 43,000 96,800 186,000 76,900 : i 810721 40,800 97,000 190,000 81,800 I 810722 35,900 90 '100 185,000 78,100 f""' 810723 33,100 87 '100 172,000 72,900 810724 34,200 86,500 168,000 69,200 810725 36,100 88,800 166,800 69,600 810726 37,500 90,200 176,000 78,700 f"""' 810727 36,300 86,500 173,000 75,500 810728 31,000 80,000 158,000 65,200 ..... -E-2-3 Table E.2.1 (Continued). Susitna River Yentna River Date Gold Creek Sunsfiine Susitna Susitna ~ 810729 28,800 75,100 146,000 60,400 810730 28,100 76,000 142,000 58,400 810731 26,200 78,900 140,000 57,300 810801 33,100 78,800 134,000 53,800 810802 51,900 126,000 174,000 68,400 810803 49,500 116,000 223,000 83,200 810804 40,200 99,400 201,000 72,500 810805 32,300 85,600 171,000 65,000 810806 27,500 76,800 154,000 61,500 810807 26,200 72,500 146,000 60,000 810808 28,800 73,600 146,000 64,400 810809 40,400 84,600 161,000 77,500 -810810 42,600 92,300 176,000 79,300 810811 43,500 95,000 185,000 84,000 810812 42,400 96 ,500 190,000 91,900 810813 46,400 104,000 217,000 113 ,000 810814 51,300 110,000 227,000 97,800 810815 50,800 118,000 223,000 83,400 810816 48,400 117,000 228,000 69,100 810817 40,900 98,500 201,000 53,500 810818 32,900 81,600 161 ,000 43,900 810819 30,200 73,000 138,000 38,300 810820 34,200 76,400 132,000 36,600 810821 41,300 82,800 137,000 39,600 810822 41,700 84,700 142,000 36,400 810823 37,900 81,600 138,000 35,000 ~~ 810824 33,400 74,700 130,000 33,600 810825 28,600 65,500 120,000 32,100 810826 25,600 61,500 113,000 32,300 810827 24,200 60,200 110,000 36,300 -810828 24,200 61,200 113,000 41,000 810829 23,900 62,100 116,000 45,400 810830 23,600 62,300 120,000 47,800 ~ 810831 22,400 60,700 120,000 48,000 810901 21,500 58,800 117,000 48,200 810902 20,200 54,800 113,000 44,000 810903 18,300 49,200 106,000 38,900 ~-~ 810904 16,600 44,400 97,800 37,200 810905 16,000 41,300 93,000 36,000 810906 15,700 40,800 90,100 36,500 -810907 15,800 40,500 90,500 39,200 810908 15,900 39,200 91,200 36,700 810909 14,500 37,000 84,900 31,000 810910 14,200 34,400 76,000 27,000 - 810911 14,300 34,200 69,800 24,500 E-2-4 - Table E.2.1 (Continued). "'"" Susitna River Yentna River -Date Gold Creek Sunshine Susitna Susitna 810912 14,100 34,600 67,100 23,300 F"" 810913 13,200 33,300 66,200 23,600 810914 12,700 31,800 63,500 22,700 810915 11,800 30,500 58,400 20,700 810916 11,300 29,000 54,200 810917 11 ,300 28,000 51,000 810918 10,800 27,000 48,000 810919 10,500 27,000 46,000 810920 11,400 28,000 44,000 810921 12,200 29,000 43,000 810922 11,600 27,000 45,000 810923 10,600 26,000 41,000 810924 10,400 24,000 38,000 810925 10,100 23,000 36,000 810926 9,560 22,000 35,000 """' 810927 8,890 21,000 34,000 810928 20,000 33,000 810929 . 19,000 33,000 810930 19,000 32,000 811001 10,500 43,000 811002 10,300 42,000 811003 10,100 40,000 811004 9,800 39,000 811005 9,520 38,000 811006 9,380 37,000 811007 9,340 39,000 811008 9,760 42,000 811009 10,100 44,000 811010 9,700 47,300 -811011 8,820 42,500 811012 8,160 38,300 811013 7,620 34,400 811014 7,290 32,500 811015 7,440 33,100 ,.. ---Data unavailable. F"' E-2-5 250 200 ,-, 0 0 0 X (/) lL 150 0 ....... w 0 m a: I <( N I I 0 0'1 100 (/) 0 50 10 20 MAY 20 JUNE 10 JULY 10 20 AUGUST PROVISIONAL USGS 1981 DISCHARGE DATA Susitna River Yentna River---------· Susitna St•llion Sunshine Gold Crook 10 20 SEPTEMBER Figure E.2.1. Hydrograph (discharge vs. time) for May-September 1981 for the Susitna River at Gold Creek. Sunshine, and Susitna stations and for the Yentna River near Susitna Station (USGS 1981}. J 1"11 I N I ....... ··~ CHINOOK t (/)<1i f~ 12· ~~ f €S ~~ ~~ 12~ ~it (/)~ ~~ Q. ~ 0 g 200 X (JJ "-8 w 100 C) a: ~ ~ i5 Spawning * Incubation • Rearing Adult Passage Spawning * Incubation* Rearing Adult Passage * Data unavailable. 1 ----Susilna Slalion (USGS 16294350) ·············•· Sunshine (USGS 152927110) --Gold Creek (USGS 162911000) 6/15 6~15 9/2 9/7 USGS .19111 Proviaianal Data Figure E.2.2. Provisional periodicity for the various life phases of chinook sal- mon as it relates to discharge of the Susitna River (USGS 1981). Consult ADF&G for further interpretation. rr1 I N I ()) COHO t ~~ f2• ~~ f 5 ~~ ~! f2~ ~ ~---a. § 200 oX U) ... 8 ~ 100 ~ :r 0 !a D Spawning • lncuballon • Rearing Adull Paaeage Spawning Incubation • Rearing Adult Pauage • Data unavailable. ----Sualtna Station (USGS 1629431ilil) 1: fl\ ·········-···· Sunahlne (USGS 15292780) P"' 1\ } I --Gold Creek (USGS 151!92000) 1 '\/V \ I ~ ~\ ,, .......... '\ 11/i II. \"' A ,, / \,..) yj\...._, 1\ 1\ \ ,u" I "V{h , { /'...... 1\.A,/' ...... J .... " \. .... I ..., .............. ~ 6/27 9/1 8/ 1 10/2 7127 9 19 USGS, 1981 Provial.onal Data Figure E.2.3. Provisional periodicity for the various life phases of coho salmon as it relates to discharge of the Susitna River (USGS 1981}. CoA- sult AOF&G for further interpretation. J rr1 I N I 1.0 ····~ CHUM L (/)l ~~ ~· ~~ f 5 ~~ ~.~ 0~ 1-o ~; ~~ Q; 0 8 200 ~ X (/) u. 8 Spawning 100 • Incubation • Rearing Adull Passagu Spawning Incubation • Rearing Adull Passage • Data unavailable. Figure E.2.4. 1 6127 1/15 4/25 715 1 17 9/ 6 9/ 6 9/1Jj USGS,1981 Provisional Data DEC Provisional periodicity for the various life phases of chum salmon as it relates to discharge of the Susitna River (USGS 1981). Consult ADF&G for further interpretation. n1 I N I Cl PINK 0 c 2 200 X Vl IJ.. 0 w 100 Cl a: <( J: 0 Vl i5 0 t Spawning " I; Incubation " ~· ~; Rearing f AduU Passage 6 Spawning ~~ • ~! Incubation oi? ..... f~ Rearing ;J ~~ 0. AduU Passage " Dala unavailable. ----Susitna Stalion (USGS 15294350) ··········•···· Sunshine (USGS 15292780) ---Gold Creek (USGS 15292000) "' f1 II M"' '' Jl I \\1\1 I I 1j 'f I I ' ~\ • "·/' ':\ • 1_, '' r I ' r. ' , \ ~ ,, I '" I \,J i • i; f, \ i\1 \./ ,.1 :· ''\ •• • ... j~f~ 1.. \ I i ~· •t ~'\ \. I :-: , .......... i ·····~ \ 1\..... :" ~ ..... , ...... ' ,.._ I -..,; -.... ' .............. JAN FEB MAR AI'R 6127 9/2 8/ 9/4 4/25 /23 /16 8 20 USGS, 1961 -Provisional Data NOV DEC Figure E.2.5. Provisional periodicity for the various life phases of pink salmon as it relates to discharge of the Susitna River (USGS 1981). Con- sult ADF&G for further interpretation. J rn I N I -' -' SOCKEYE t ~~ l:?· ~~ ~ 0 g 200 X . (J] u. 0 1'j 100 ~ l: () (/) i5 Spawning * Incubation* Rearing ] ----Susitna Station (USGS 15294~b0) ·••·····••·•·•• Sunshine (U3GS 15292790) ---Gold Creek (~SG~ 152?2000) USGS, 191M Provisional Data f Adull Passage 6/23 9/4 6 Spawning 8/ 9/ 5 ~~ ~~ Incubation* 0~ ~'-• !; Rearing ' ~~ Adult Passage 71 9/29 a: . • Data unavailable. Figure E. 2. 6. Provisional periodicity for the various life phases of sockeye sal- mon as it relates to discharge of the Susitna River (USGS 1981). Consult ADF&G for further interpretation. 1981a, b, d), field observations by Su-Hydro and other ADF&G personnel, and review of drafts of these charts by Su-Hydro staff. The data presented in these charts are in a preliminary stage of refinement and the ADF&G should be consulted regarding their interpretation. Periodicity charts were not developed for resident fish species due to insufficient data. Generally, passage of adult salmon corresponded with the peak periods of the hydrograph (Figures E.2.2 -E.2.6). Spawning of adult salmon occurred during the waning of the peak flow periods. However, passage of adult salmon on a day to day basis, as monitored by daily sonar counts of adult salmon (Figures E.2.7-E.2.11), indicated that salmon movements decreased during periods of highest flows and increased as flows subsided following major flow events. Apparently, peak flows, with the corresponding increased water velocities, discouraged passage and encouraged milling. 2.3 Percent Incidence of Selected Fish Species in Relation to Discharge The percent incidence of catch for three fish species at habitat sites* between Talkeetna and Devil Canyon were compared with mainstem Susitna River discharge at Gold Creek from June through September 1981 (Figures E. 2.12 - E.2.14). Percent incidence of catch equals the total number of habitat locations where at least one individual of the target species was captured, divided by the total number of habitat locations that were sampled during a designated sampling period, multiplied by 100. * See ADF&G 1981a, c, d, f and g for descriptions and listings of habitat locations. E-2-12 - - - - - - - - ~""' - - - ADF&G SONAR STATIONS 350 260 "' ... z ::> 210 0 SUSITNA STATION u (AM 26) 0: .. z 140 0 / "' 70 75 60 "' ~ I >-z ::> 45 0 YENTNA STATION u ,~-\J (TAM 4) 0: .. z 30 0 Ul 15 300 240 "' ,... z 180 ::;) 0 SUNSHINE STATION u a: (AM SOl .. 120 z 0 <J) 60 125 100 <J) ~ CHINOOK /i ' ! l 1 200 0 0 :: 150 ::2 u '" <:l 100 0: .. :r w 5 50 0 150 0 ~ ~ u 100 '" <:l a: .. :r u 50 ~ " 150 0 ~ ::2 u 100 - 50 150 '" (!1 0: .. z u "' 5 0 0 ~ USGS GAGING SITES SUSITNA STAT\ON (USGS 15294350) (AM 26) YENTNA RIVER (USGS 15294345) (TRM 10) SUNSHINE [USGS 15292780) CAM 84j TALKEETNA STATION 8 (AM 103) 0: .. z 0 75 ::2 100 u GOLD CREEK (USGS 15292 OOOJ [AM 137] Figure E. 2. 7. 50 "' 25 ·--·- 6/20 S/30 7/10 7120 7130 8/10 8/20 8/30 9/10 DATE Daily Sonar- Count Dischar-ge ( CFS x 1000) w <:l 0: .. z 50 u <J) 5 Sonar counts of adult chinook salmon at each AA sonar site as compared to discharge of the Susitna River (adapted from USGS 1981 and ADF&G 1981a). E-2-13 AOF&G SONAR STATIONS SUSITNA {AM 26] YENTNA (TRM 4) SUNSHINE (RM 80) TALKEETNA cAM 103] Figure E.2.8. ~' z 5 () 0:: <: z 0 "' "' z :;:, 0 () 0:: <: z 0 "' 0:: < z 0 "' 0:: <: z 0 "' 3000 2400 1800 1200 600 1500 1200 900 600 300 2500 2000 1500 1000 soo 250 - 200 - 150 - 100- so COHO (~~ i .-..... _ .. /\ ' ' \ . .i ,·, _.•"';,M_ ~ ;) ._..,...,-J 1 I I \k ' '·,j 1'1 I I I \ r.J \ I . A !"l ' \ \..: 6120 6/30 7! T-0 7/20 7130 8/TO 8/20 8/30 9/10 DATE I- I Oa•~v Sonar C.:ii.lnt C)!~charge ( CFS x 1000 ) 200 150 "' 50 150 so 150 G c c 2 0 0 2 100 "' G 50 USGS GAGING SITES SciSITNA ST A liON [USGS 15294350) (RM 26) SUNSHINE iUSGS t 5292780) (RM 84) GOLD CREEK cusc: 152920000) (AM t37l Sonar counts of adult coho salmon at each AA sonar site as compared to discharge of the Susitna River (adapted from USGS 1981 and ADF&G 1981a). E-2-14 - - - - - - - - - - - - - - ,... - - - - ADF&G SONAR STATIONS "' f-z ~ 0 SUS I TNA STA T!ON U (RM 26) a: < z 0 "' (/) f-z ~ YENTNA STATION 8 (TAM 4) a: SUNSHINE STATION (RM 80) < z 0 "' "' f-z ~ TALKEETNA STATION 8 CAM 103) a: < z 0 "' 2500 2000 1500 1000 500 1000 .aoo 600 400 200 5000 4000 3000 2000 1000 700 560 420 280 14{) CHUM : '·-~--.. 8/20 6/30 7110 7/20 7130 8110 8/20 8/30 9110 DATE Daily Sonar Count DischarQe ( CFS x 1000 ) 200 150 100 50 150 ~ 100 a: < i'5 "' i5 50 0 150 100 :f () 50 150 100 ~ () w 0 a: 50 ~ () "' a USGS GAGING SITES SUSITNA STA T!ON (USGS 15294350) (RM 26) YENTNA RIVER (USGS 1 5294345) [TAM 10) SUNSHINE (USGS 15292780] (AM 84] GOLD CREEK (USGS 1 5 292000) CRM 137) Figure E.2.9. Sonar counts of adult chum salmon at each AA sonar site as compared to discharge of the Susitna River {adapted from USGS 1981 and ADF&G 1981a). E-2-15 ADF&G SONAR STATIONS SUSITNA STATION [AM 261 YENTNA STATION [TAM 4) SUNSHINE STATION [RM 80) TALKEETNA STATION [RM 103) U) 1-z 5 u "' <( z 0 "' "' 1-z :l 12,500 10,000 7500 5000 2500 3250 2600 0 1950 u a: <( PINK ! \ } ~ _; ' ;.·--·· .•. \. ...... ····.\. ......... 5 1300 Cl) / •• -· .............. .. "' 1-z 650 9000 7200 5 5400 u 0: < 5 3600 "' 1800 6/20 6/30 7/10 7120 7/30 8110 8/20 8/30 9/10 DATE ~--O.aily Sonar Couni Di~char(le ( CFS X 1000 ) 200 150 100 50 150 100 50 0 150 100 50 50 0 0 = U) "-u LIJ '-' 0: < ::t: u "' 0 0 g "' u.. u "' '-' a: <( ::t: u >:! c 0 0 = U) u.. u w '-' 0: <( ::t: u >a c 0 0 0 ~ USGS GAGING SITES SUS\TNA STATION [USGS 1 5294350] [AM 26] YEN TNA RIVER (USGS 15294345] [TAM 10) SUNSHINE [\JSGS 15292780] CAM 84) GOLD CREEK (USGS 15292000) CAM 137) Figure E.2.10. Sonar counts of adult pink salmon at each AA sonar site as camp a red to discharge of the Sus i tna River (adapted from USGS 1981 and ADF&G 1981a). E-2-16 - - - - - - - - - - P"" '""" ~ ... ~Iii!! ""--- r- - """' - - ADF&G SONAR STATIONS SUSlTNA STATION (RM 26) YENTNA STATION {TRM 4) SUNSHINE STATION (AM 60) TALKEETNA STATION (AM 103) "' ,... :z 32,500 26,000 6 19,500 (.) J: < g 13,000 "' 6500 16,500 13,200 "' ,_ z :J 9900 0 () "' < z 6600 0 CD 3300 9000 7200 "' ,_ z :J 5400 0 () "' < z 3600 0 "' 1800 375 300 "' ,... z :J 225 0 0 "' < 150 z 0 (j) 75 Figure E.2.11. SOCKEYE USGS GAGING SITES /""1 I 200 0 0 ;:! 150 "' u. () SUSITNA STATION w (USGS 15294350) (!l 100 a: (RM 26) < J: () "' i5 50 150 0 0 ;:! '~ (f) u.. TOO () YENTNA RIVER H ,, w (USGS 15294345) ~ I ·, v'\j\J \ G (TRM 10] J: < J: () \/\ 50 !!! 0 -"' -\'- ' 0 150 0 0 / ;:! i I .. , 100 "' ! f u. SUNSHINE (.) \ /\ \/ \ (USGS 15292780) \'-\ w G CAM 84) "' \ 50 < a: ---~--() "' i5 150 0 0 ;:! 100 (j) u. () GOLD GREEK w (USGS 15292000) (!l (RM 137) a: < 50 J: 0 (j) i5 0 6/20 6130 7110 7120 7130 8110 8120 8130 9/10 DATE Daily sOnar Discharge Count ( CFS x iOOO ) Sonar counts of adult sockeye salmon at each AA sonar site as compared to discharge of the Susitna River (adapted from USGS 1981 and ADF&G 1981a). E-2-17 IT1 I N I ...... co 100 6 o----<1 Discharge BUR BOT ~ Percenl Incidence 6 80 ;-"\ 0 0 0 4 T"" 60 X C/) lL 8 3 w Cl 40 a: < J: 0 2 C/) -0 20 1 May June July August September October Figure E.2.12. Changes in the percent incidence of burbot catch in the Talkeetna to Devil Can- yon reach of the Susitna River as it relates to mainstem discharge of the Susit- na River at Gold Creek (adapted from USGS 1981 and ADF&G 198lf). J w 0 z w 0 0 z ..... z w 0 a: w a. .) m I N I I-' 1.0 o--o Discharge RAINBOW TROUT l!,')iS:yJ Percent Incidence 6 r"\ 0 0 0 4 .... )( C/) u. 8 3 w CJ 40 0: < :c 2 0 C/) 0 20 1 May June July August September October Figure E.2.13. Changes in the percent incidence of rainbow trout catch in the Talkeetna to Devil Canyon reach of the Susitna River as it relates to mainstem discharge of of the Susitna River at Gold Creek (adapted from USGS 1Y81 and ADF&G 198lf). w 0 z w 0 0 z 1- z w 0 0: w 0... rn I N I N 0 J 6 .,.... 0 0 0 4 ,... X en 1L 0 3 ~ w (!) a: < :I: 2 (J en 0 1 May CHINOOK SALMON (AGE 0+) June July August 00 <>----'> Discharge F~:.c',~:,;J Percent Incidence September October Figure E.2.14. Changes in the percent incidence of chinook salmon fry tage 0+) catch in the Talkeetna to Devil Canyon reach of the Susitna Kiver as it relates to mainstem discharge of the Susitna River at Gold Creek (adapted from USGS 1981 and ADF&G 19131 f) • ,} w 0 z LU 0 0 z 1- z LU 0 a: w a.. - Burbot, rainbow trout, and juvenile chinook salmon {age class 0+)* were selected for analysis because sampling techniques used to capture these species remained consistent throughout the open water season. Accardi ngly, the percent incidence figures reflect actual changes in fish distribution. Percent incidence for each species was ca 1 cul a ted for minnow traps and trot lines for each two week period between June and September 1981. An equivalent number of study sites were sampled at mainstem {5), slough and side channel (7), and tributary mouth (5) habitat locations. Discharge data used in this analysis were recorded at the Gold Creek gaging station (USGS 1981). The percent incidence for all three species may not represent actual fish distribution for the June 1 through 15 and September 16 through 30 sampling periods due to limited sampling efforts. Likewise, data collected during peak discharge events may reflect gear efficiency rather than the influence of discharge on the suitability of fish habitat. Changes in the percent incidence of burbot catch appear to coincide with similar changes in discharge (Figure E.2.12). Burbot were captured at fewer locations during low flows resulting in a corresponding low percent incidence of catch. The relative increases of both percent incidence of burbot catch and discharge may indicate that additional suitable habitat is available at higher flows. Burbot catches, during low flow conditions, were primarily restricted to the mainstem Susitna and deeper slough and side channel habitats. During higher flows, burbot were captured at a greater number of habitat locations, including shallow side-channels, sloughs, and tributary mouths. *Age was determined by length/frequency and scale analysis (see ADF&G 1981d). E-2-21 - - 1""' 0::: ~ c 10 ,....., o::J -+-' V) OJ 3 ,_c en :;:::5 0 r- tn -+-' 10 -+-' OJ V) -+-' OJ c •r--~ ,...... Q) -+-' -10 r- 0.. - E-2-22 - - The percent incidence of rainbow trout catch illustrates an apparent inverse relationship to changes in mainstem discharge (Figure E.2.13). Rainbow trout were captured at a higher percentage of habitat locations during June and September 1981 (when mainstem discharges at Gold Creek ranged from approx- imately 10t000 to 20t000 cfs) than during July and August 1981 (when mainstem discharges generally ranged from 20,000 to 50,000 cfs). The change in percent incidence of catch could be explained by the migrational patterns of rainbow trout. Habitats utilized seasonally by rainbow trout for overwintering, spawning, and summer feeding vary (Scott and Crossman 1973; Morrow 1980). During the winter, rainbow trout are only captured in isolated slough and mainstem study sites, resulting in a low percent incidence of catch. As spring approaches and fish begin to migrate to tributaries to spawn, the rainbows are found in a greater range of study site habitats, corresponding to a higher percent incidence of catch during this period. Once the spring spawning migration is completed and the fish have relocated into the tribu- taries for spawning and summer habitat, the fish are found at fewer study sites, corresponding to a lower percent incidence of catch. As freeze-up begins and the fish outmigrate from the tributaries, they are again found to inhabit a greater range of study habitats, resulting in a higher percent incidence of catch. The percent incidence of catch of chinook salmon fry in the Talkeetna to Devil Canyon reach of the Susitna River appears to be a function of fish growth (Figure E.2.14). The percent incidence of catch of these fry is relatively low in early June and increases at a steady rate through September regardless of fluctuations in discharge. The average total length of age 0+ chinook salmon increased from approximately 45 mm in early June to 75 mm in late September (ADF&G 198ld). Therefore, it appears that as juvenile chi nook salmon increase in length, they inhabit a greater variety and number of the habitats sampled (e.g. includes areas having higher water velocities). - - 2.4 Percent Trapping Incidence of Selected Fish Species in Relation to -· Point Specific Deoth and Velocity Point specific data* are required to ascertain the degree and extent to which specific habitat criteria (e.g. depth, velocity, substrate, water temperature, etc.) are utilized by an individual fish species for each life phase (i.e. spawning, incubation, rearing, and passage). These data provide the basis for defining the types and ranges of habitat characteristics which are associated with the continued existence of various 1 ife phases of a fish species. By comparing point specific utilization criteria with hydraulic data (which quantifies the wetted area having various point specific values at a range of discharges), one can predict the potential impacts of various flow regimes on fish habitat availability. Point specific data (ADF&G 1981c) were collected at RJ fish trapping sites during the 1980-1981 field season. Evaluation of substrate characteristics was prevented when turbid water conditions were present. Fish trapping locations were selected on the basis of professional biological judgment, the primary objective being to select locations optimum for capturing fish as - - - - - opposed to selecting locations representing the range of habitat types present ~ * Data collected in the same vertical water column and depth (or mean depth of the water column) as an organism or object of interest. E-2-24 .... - E-2-25 N OJ +-' rtl ....... 0.. - -I at the individual fish collection site. Accordingly, interpretation of 1981 observed relationships between trapping incidence and point selected depths and velocities is limited to the distribution of depths and velocities occurring at specific trap sites. Analytical limitations resulting from this restricted sampling distribution can be partially overcome from a statistical (or data analysis point of view) by controlling for the given sampling distribution (the range over which the parameters were actually sampled). However, interpretation of trapping incidence as it might be affected by depth and velocity would then only be valid from a statistical point of view. Two exam~les of trapping incidence (juvenile chinook salmon captured in baited minnow traps and rainbow trout captured on baited trotlines) versus point specific depth and mean column velocity are presented q.s illustrations (Figures E.2.15 and E.2.16)*. The sparse sampling effort in terms of the larger depths and velocities (Figures E.2.15 and E.2.16) may indicate that a narrow range of habitat types with these larger depths and velocities was sampled. Generally, it appears that both juvenile chinook salmon captured in minnow traps and rainbow trout on trotlines are collected in all of the depths and velocities from which they are sampled (Figure E.2.15 and E.2.16). However, this apparent relationship may only be a function of the limited * Note that the top two graphs on both figures represent the total sampling distribution of the appropriate gear in terms of depth and velocity. The bottom two graphs represent the number of traps or trotlines in which at least one individual of the appropriate species were collected. E-2-26 m I N I N ........ 775 (f) 620 11. <! £Y 1-465 J 0 z 310 z H :L * 155 0 165 (f) 1 32 11. <{ (Y t-99 J 0 z 66 z H L: * 33 TOTAL TRAPS SET 1360 (f) 1088 11. <i IY N 2934 1-616 N 2443 3 0 z 544 z H I: * 272 e 0.00 2.10 4.20 6.30 8. 40 10.50 0.00 121.7121 I. 40 2.10 2.60 3.50 SAMPLING DEPTH (ft.) SAMPLING VELOCITY (fl/s) TRAPS WITH FISH N = 660 0. 00 2 . I 121 4. 20 6. 30 B. 4121 10. 50 COLLECTION DEPTH Cft) 335 (f) 268 Q_ <( n:: t-201 J 0 z 134 z H L: * 67 121. 00 0. 70 I . 40 2 . I 0 2. 80 3. 50 COLLECTION VELOCITY Cfl/s) FigurE.2.15. Trapping incidence data for juvenile chinook salmon versus point specific depth and mean column water velocity data collected in minnow traps at habitat locations. 1981 (ADF&G 198lc and d). -I rr1 I N I N co -... 1 1 TOTAL TRAPS SET (f) w z H ..J t-o 0:: I- 0. 00 I . 70 3. 40 5. 10 6. 80 8. 50 SAMPLING DEPTH Cfl) t-o ~ 1- * 0~00 0.95 I .90 2.85 3.80 4.75 SAMPLING VELOCITY Cfl/s) TRAPS WITH FISH e . 00 1 . 10 3 . 40 s. 1 0 6. a0 a . sa .1J COLLECTION DEPTH Cft) 16 (f) w z H 12 -' t-o 8 l:k:: I- "" 4 0 Figure E.2.16. Trapping incidence data for rainbow trout versus and mean column water velocity data collected by locations, 1981 (ADF&G 1981c and f). 0 . 00 0. s5 1 . se 2 . 65 3 . 60 4 . 75 COLLECTION VELOCITY Cfl/s) point specific depth trot lines at habitat sampling distribution chosen. Without information on the distribution of depths and mean column velocities in the habitats sampled, it is inappropriate to conclude that these fish utilize a particular depth or velocity. These data can however be viewed to represent the effectiveness of various types of sampling gear to collect a particular species in the habitats sampled. Improvements in this data base will be necessary to better define the ranges of physical characteristics utilized by fish. Fish distribution and habitat utilization field crews will be segregated in 1982. This will enable habitat utilization crews to concentrate their efforts at specific sites and better define the range of point specific habitat criteria utilized by fish (i.e. - sample with the primary objective of identifying fish habitat utilization """ rather than of catching fish). Sampling methods will be employed which permit fish to be observed in the habitat they are occupying, that is techniques which do not attract fish to sampling sites or at least reduce the extent to which a technique will attract fish to a sampling site or to leave the habitat originally occupied. These methods could include: direct visual observation, electrofishing, seining, baited* and baitless (and possibly modified) minnow traps, radio telemetry, and nets. In addition to perfecting these sampling approaches, modifications to substrate evaluation techniques will be adopted so that methods become more uniform and practical {in terms of application to the Susitna River drainage). * A series of baited minnow traps which are equally distributed along a transect to ensure that a variety of habitats are sampled while at the same time reducing the bias of baiting traps. E-2-29 ~ .... 2.5 Bering Cisco Spawning Habitat Evaluation Although Bering cisco were not previously known to occur in the Susitna River system, spawning activities of these fish were observed by RJ/AH electro- fishing crews downstream of Ta 1 keetna in 1981 (ADF&G 1981 f). Although four major areas of spawning activity were located between R.M. 75 and R.M. 80, the extent of Bering cisco spawning activity in other portions of the Susitna River is unknown. A discussion of the life history of the Bering cisco and 1981 catch data are presented in the RJ subject report (ADF&G 1981f). A preliminary habitat evaluation of these three spawning areas was undertaken to begin understanding the habitat characteristics associ a ted with Bering ci sea spawning. The results of the surveys are presented in Tab 1 e E. 2. 2 and Figures E.2.17 to E.2.19. Bering cisco were observed to spawn in relatively shallow water, riffle, and bank zone areas. Substrate used for spawning ranged from silt/sand (particle sizes less than 1/16 11 ) to cobble {particle sizes 3 11 -6 11 ), with gravel (particle sizes 111 -3 11 ) and cobble being predominant. Mean water column velocities and water depths were measured at the surveyed spawning areas as described in Bovee and Cochnauer (1977), and ranged from 1.5 to 4.7 ft/sec. and 1.4 to 1.9 ft deep respectively. Surface water temperatures ranged from 3.0 to 3.8°C. The limited number of spawning sites evaluated {Table E.2.2 and Figures E.2.17 -E.2.19) may not represent the range of conditions characterizing Bering cisco spawning habitat. Accordingly, continuation of these detailed studies are planned for Phase II in 1982. E-2-30 Table E.2.2. Bering cisco spawning site evaluation on the Susitna River, October 10-13, 1981 (adapted from ADF&G 1981c, f)~ Specific Mean Spawning Mean Spawning Conduc-Dis~ Depth Velocity Water tance solved Temp. (umhos Oxygen Standard Standard Site (OC) pH /em) (mg/1) (ft) Error ft/sec Error Substrate Sunshine 3.8 7.0 127 12.3 1.50 0.08 1.50 0.12 40%:1"-3"gravel (R.M. 78-79) 25%:3"-6"gravel (combined riffle and (n=39) 20%:silt & sand gravel bar zone) 10%:1/4"-1"gravel Montana 1 3.0 7.0 131 13o4 1.38 0.16 2.23 0.27 30%:1"-3"gravel n1 (R.M. 77-77.5) 30%:3"-6"gravel . I N (gravel bar zone) (n=12) 20%: silt & sand I w 10%:1/4-1 11 gravel Montana 2 3.3 6.8 128 12.6 1.64 0.09 1.66 0.12 30%: l"-3''gravel ~R.M. 76-77) 30%: 3''-6"grave 1 upper riffle zone) (n=18) 20%:silt & sand 10%:1/4"-1"gravel Mainstem-West Bank 3.1 7.0 134 13.0 1.85 0.12 4.67 0.25 40%:1 11 -J"gravel ~R.M. 75.0) 20%:3"-6"gravel gravel bar zone) (n=l2) 20%:sand & silt 10%:1/4"-l"gravel .-- - _.-ao'_..\ : -~\ 0.5/1.3* 1.111.4 2.0/3.0 . . . . \'• ~:::· . ;?\0 ':::·. i7/1.9 12/2.7 1.813.4 . . .·~c. . . . .. • • • -: . 1.0/2.2 1.5/2.8 1.8/3.8 . . .. . . . . . ::.....-.· .. 1.5/1.4 1.811.7 . . 1.0/0.8 1.5/0.8 0.710.7 1.711.2 2.3/1.2 .. .. . . . . . .. . , .. , 1.0/0.8 1.4/1.1 2.112.3 .... • . . . . .. . . . .. . .~ . : 1.1/0.8 1,9/1.3 2.2/1.5 co .. ·. . .0 .. . . :·-: .'i .. =' > .... co .. 12/0.7 1.7/1.0 2.0/1.5 . ... . .•. Cl . .. .. : .. . '• .. . . ... 1.111.0 2.0/1.3 2.5/1.4 . . ·.· · ... · . . .. . : .. 1.4/1.1 1.9/1.2 2.3/1.5 1.0/1.0 1.5/1.4 2.0/1.9 1.0/0.7 1.8/1.5 2.0/1.9 so' --.J "'--~ cc ~ ~ ·-~ (f) • depth (ft) I velocity (ftlsecJ Figure E.2.17. Bering cisco spawning area on the Susitna River at Sunshine, R.M. 78.0 to R.M. 79.0, October 13, 1981 (adapted from ADF&G 198lf). E-2-32 . . . . ill ; . : .. _:.: . . -.,_ ... . . . . .. . . . • ._ • II • : • 4 80' 4( ) .... . .. .. . ; . . . . .. " . 0.6/0.8* 0.9/1.7 1.8/3.2 ... . " ..... ~ . . .. 41 ....... -~ ... ·.:: . . . Cl •• tr 0.7/1.9 1.3/2.6 2.0/4.1 . . . : . . . .• 5001 . . . . . a • • • . .. 1.0/1.5 1.7/2.4 2.013.0 ·' 1.0/12 1.5/2.0 2.112.3 ' -~ 0.911.3 1.6/1.3 1.811.8 ~ . . .. .. , • tl ... 2500 ·:·: 1.4/1.7 1.7/2.2 2.0/2.5 I •-. . . . ., • e CJ :.:: .. . .... .. . . 41 .. ., : ... .. . . ... 4 ' ..... 0-. . • 0 • .. : 0 'II ... . ~ .... . 1.411.3 1.0/2.1 1.5/12 1.8/1.1 2.0/1.5 1.8/1.4 2.311.9 1.5/2.3 2.112.5 Site 2 Riffle Zone Site 1 Gravel Bar Zone ... 80' I * depth (ft) I velocity (ftlsec) Figure E.2.18. Bering cisco spawning area on the Susitna River at Montana Creek (Sites 1 and 2), R.M. 76.0 to R.M. 77.5, October 15, 1981 {adapted from ADF&G 198lf). E-2-33 - - - ~ - - - - - - - - - - · . .... ! : • . .. , :. . . : .·. . . .. . . .... ·. . . ' . . . ':' . . : ·: ~: ... . . ,. .. . . .. .. . · ... . .. . . . .• . . .. ~ .... . . .. ·~· .. . . . ... . . . .. . : gravel bar gravel bar : .· ~~. . . . * depth (ft) I velocity (ftlsec) . .: •· . . . .. ·~ • I •'• :: ... ... . . :·: ... • .-• I ~ .:..= ......,_10-..f .. ~: . ::: * 1.513.6 2.5/4.5 1.5/4.5 2.3/5.8 1.5/4.5 1.9/5.4 1001 1.0/3.5 2.0/5.4 2.0/5.8 2.014.8 22/5.0 .. Figure E.2.19. Bering cisco spawning area on the Susitna River at mainstem West Bank R.M. 75.0 October 13, 1981 (adapted from ADF&G 1981f). E-2-34 2.6 Matrixes of Fishery and Physiochemical Observations Matrixes of the ranges of physiochemical parameters measured {ADF&G 1981c) and life phases of fish* species (ADF&G 1981a, d, f, g) captured or observed during the open water {May-September, 1981) field season at each general - habitat evaluation study site**, grouped by river reach, are presented in Tables E.2.3 to E.2.7. Selected habitat slough evaluation site** data are presented in Table E.2.8. This information is intended for use as a general indication of the relative changes in water quality over the five month open-water sampling period in 1981 and to catalog fish species observed at the time of sampling. The physiochemical data do not represent the full range of seasonal habitat conditions used by the life stages of fish species included in the matrix. Species lists for each location do not necessarily include all species and life phases present at that location. Further study combined with additional analysis data collected prior to 1981, will be required to define patterns of fish occurrence and the habitat criteria associated with these patterns. Keeping these limitations in mind, some provisional conclusions can be derived from these matrixes. Adult anadromous salmon species have not been observed in the impoundment study reach, supporting the belief that hydraulic characteristics of the Susitna River at Devil Canyon may act as a barrier to salmon movement. The higher number of fish species present in the lower * ** Arctic 1 amprey (Lampetra japoni ca) may represent both anadromous and resident forms {ADF&G 1981f). Descriptions and locations of these sites are presented in the AA, AH, and RJ subject reports (ADF&G 1981a, c, d, f, g). E-2-35 - - - - - - ITI I N I w 0'1 1 --J Table E.2.3. Matrix of observed fish species and physiochemical parameters for habitat locatiuns in the Yentna study r~ach uf the Susitna.River, May-September, 1981 (adapted frum ADF&G 1981a, c, d, f, g). Cunsult ADF&G fur futher interpretatiun. HABITAT LOCATION fhh Creek A I exander Creek SHeA SHe B Site C Anderaon Creek Kroto Slough Mouth Halnstem Slough Hld·Kroto Slough Deshka River Site A Site B Site C Delta Island little Willow Creek l ADF&C 1!178 Anadromou& X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X ---Data not collected, X X FISH SPECIES X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X Resident X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X :: .. ... .~ 1 .... •r • ... :a ... :I 0 ... .. t: ... , .. ... ;a. .. " 4.~ !.1.6 ·-9.7 8,9 -10,2 9.0 -9,7 8,4 -9.6 8,, -11.3 8,3 -9.9 9.7 -12,0 9.8 -10,9 8.2-11.4 8.4 -H.5 8.5 -12.0 9.7 -10,6 9,9 -12.- 6,9-7,2 7' 1 6.~ 1-7.1 6.5 -7.9 6,8 -9,7 7.0 -9,2 7.3 -7.4 6.6 -7.~ 6.0 -7.0 6.0 -6,9 7,6 5.5 -6.9 PHYSIOCHEMICAL PARAMETERS 11't -118 78 -99 78 -96 76 -95 70 -123 80 -199 88 -137 94 -132 39 -80 29 -66 28 -~7 103 -118 34 -39 210.00 -230.00 1 .~o -29,oo 2.50 -36.00 ,99 -2-.00 ~.00 -190.00 18,00 -150.00 24.50 -225,00 21.00 -200.00 3.10 -90,00 1.60 -3.60 2 .oo -5.~0 110.00 -150.00 1.50 -28.00 12.~ -13.6 11.6 -1~.~ 11.7 -15.~ 12.3 -17.8 6.0 -1~.3 5.9 -16.8 3.6 -1~.9 8.9 -15.2 5.~ -15.8 3.9 -19.~ ~.1-16.2 10.9 -13.2 2.0 -15.5 ... ;."( 19.2 -21.0 11.0 -12.2 12.0 -15.5 12.5 -21.0 6.1 -21.~ 10.1 -25.0 8.1 -. 15.8 13.7 -21.0 6.0 -18.0 6.0 -20.8 7.0 -22.~ 15.~ -3~.0 12.0 -31.0 3 ).; ... O•r •r 1J .. , !'~ ..... ..... oz. fl" C•r .. ::~ ..... .,_, I"Tl I N I w ..... Tab I e E. 2 . 4. HABITAT lOCATIOII Matrix of observed fish species and physiochemical parameters for habitat locations in the Sunshine study reach of the Susitna River, May-September, 1981 (adapted from ADF&G 1981a, c, d, f, g). Consult ADF&G for further interpretation. X X X X X Anadromoua. X X X X X X X X fiSH SPECIES X X X X X X Re&ldent X X X X X X X X X :J .. ... .. .. ·::: 1 .... _., .: ..... ~ ... ii: ... , 01;: " .. .. u .... .! ""' .... f .... fc :1! 4.- 2 ti "' =-o-... ::::. u· 'ii-.. .. i5 "' ... 8.9-12.1 6.9 -7.5 9.8 -12.9 6,4 -7.1 1.6-11.3 6,1 -7,0 a.o • 12.1 6.8 -7.6 PHYS I OCHEH I CAl PARAMETERS f " .. .. tl .. I c t-.. f ~fi ,._ " p :J}' ... .. .:!t .. ~ .. "' 1: it ... :O:i II ... -'o ·~!;; ., ... .... .. -f-.. .. $ " .i! < ... 67 -72 61.00 • 150.00 8.5 -1~.2 12,2 -17.4 24 • 36 ll.SO-ll2,00 6,4 • 12.'-10.ll -21.2 27 -~6 1.00 -1.90 9,0 -16.0 12.8 -16.0 68 -216 21.00 -210.00 6,"4 -10.8 10.2 -16,0 Ruol:ic Wlldern••• Ka•hwltna River Ca$well Creek Slouyh-Weot B•nk Sheep Creek Slough Goo•e Creek X X X X X X X X X X X X X X X X X X X X X X X X X X X X 9.3 -11.0 6.1-7.2 29 -47 2.20 -ll,OO 1.a -1o;o 12.0 -21.6 (!.ower) 1 GoO:io& Creek (lower) 2 X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X 9,2 -12.2 10.ll • 12.1 10.6 -12.1 10.5 -12.6 6.1 -7.1 6.0-7.1 6.8 -7.7 6.7 -8.0 18 -37 0.40 • ll.SO 6,3 -10,7 9.6 -17.8 HI -27 0.63 -3.ll0 7.3 -10,3 11.8 -18.6 56 -85 9.10-120.00 7.7 -11.0 --- 76 -"2 6.30 -255.00 1.2 -10,0 5.5 -16.ll ~ 'i .e. .. uu o-~ ·~ ... "" ~~ a. .. ...... o .. D. tlc C·~ .. .. .. .. ... .... o..-q 1,2 1,2 1,2 Goose Creek Slough Hal n•tem·West Bank Honl:ana Creek Sun•hlne Camp X X X X X X X X X X X X X X X X 1 ,2 ,3 10.0 -11.9 6.0 -6.7 21 -37 0.30 -1.70 10.9 -12.6 13.4 -18,6 1,2,3 fhhwheel 1 AOf&G 1976 2 AOF&G 1977 3 AOF&G 1978 X ---Data not collected. .I X X X X X X X X X ------------------ _I rrl I N I w CX> 1 ] Table E. 2. 5. Matrix of observed fish species and physiochemical parameters for habitat locations in the Talkeetna study reach of the Susitna River, ~1ay-September, 1981 (adapted from ADF&G 1981a, c, d, f, g). Consult ADF&G for further interpretation. HABITAT LOCATION Halnsteon 1 SunshIne Creek Bl rch Creek 51 ough Birch Creflk C..che Creek Slough C..che Creek Whlske" Creek Slough Whiskers Creek Slough 6A Laoe Creek Halosteon 2 ~ AOF&G 1974 l AOF&G 1976 4 AOF&G 1977 AOF&G 1970 Anadroonouo X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X ---Data not collected. fiSH SPECIES X X X X X X X X X X X X X X X X X X X X X X X X X X Rnldent X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X 1,2,3 1,2,'• 1,2,4 1,2,'• 1,2,4 10.3 -11.3 9.8 -10.9 9.4 -10.3 9.4-11.1 11.2 -12.3 5.0 -12.3 10.5 -11.6 10.7 -12.8 11.0 10.9 11.6 6.4 -7.5 5.6 -7.3 6.2 c 7.4 5.7 -7.2 6.2 -7.7 5.7-7.3 5.3 -6.6 5.1 -6.6 5.6 -7.1 6.4 -7.2 6.6 -7.4 PHYS I OCilEH I CAL PARAMETERS 78 -145 40 -65 67 -132 43 -100 57 -135 31 -304 18 -43 15 -31 42 -113 45 -65 98 -158 25.00 -170.00 1.60 -23.00 2.40 -95.00 0.50 - 7 .so oo.oo -270.00 0.60 -22.00 o.so -23,00 0.60 -3. 70 1.00 -22.00 0.60 -5.40 13.00 -135.00 f I 7.7 -12.8 8.9 -15.5 8.4 -16.0 8.8 -15.4 4.9-14.1 s.s -11.9 7.6 -18.0 7.6 -16.2 4.8 -16.5 5.2 -9.8 5.3 -15.2 9.4 -10.0 8.0 -18.2 8.0 -20.0 9,0 -1!1.6 s.o -23.0 12.0 -24.5 10.0 -23.6 11.0 -23.0 7.0-22.4 7.0 -21.8 7.0 -18,0 1,2,3 1,2,4 1,2,4 1,2,4 f11 I N I w \D Table E.2.6. Matrix of observed fish species and physiochemical parameters for habitat locations in the Gold Creek study reach of the Susitna River, t·1ay-September. 1981 (adapted from AOF&G 198la, c, d, f, g). Consult AOF&G for further interpretation. HABITAT lOC.,TION Curry Side Channe 1 Gravel Bar Slou9h 8A 4th of July Co·eek Slough 10 Slough 11 Inside Bend Indian River Slough 20 Island Portage Co•eek Hell copter Si teo Indian River 1 Indian River 2 Indian Rl ver 3a Indian River 3b Portage Creek 1 Portage Creek 2 Portage Creek 3a Portage Creek 3b ~ ADF&G 1974 3 ADF&G 1976 4 ADF&G 1977 ADF&G 1978 Anadromous X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X ---Oat a not collected. fiSH SPECIES X X X X X X Reo! dent X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X ·X X X J X X X X X X X X X X X X X X X X X X X X X X X X .. u 1: ! . .... ·-. ..... _ '0 ..... ,. a .. x: c .. l; 2,3,4 2,3,4 2.3,4 2,3,4 2,3;4 2,3,4 c u !!': &-:: "D ... !! 0 .. .. i5 9.1 -10.9 9.5 • 10,3 9.6-11.0 8.8 -10.5 9. 2 -10.1 9.0 -11.5 9.3-10.7 10.4 -11.8 8,6 -10.6 10,3 -11.0 10.2 -11.9 9.5 -11.0 10,6 -12.3 6.8 -12.0 10.7 10,0 -11.8 10,2-12.1 10.3 -12.3 10.4 10,6 -12.3 7,2. 7,5 6.7 -7,6 7.3-7,8 6.8 -7,6 6.3 -6.7 7.0-7.8 6.8-7.1 7.0 -7.6 6.4 -7.4 6.9 -7,6 7,2 -7.5 6,6-7.1 5,6 -6,7 5,9 -6.8 6.8 6.0 -6.3 6.9 6.7 -6.9 7.2 6.1 -6.8 PHYS IOCifEHICAL PARAH.ETERS 96 -152 77 -129 104 -167 108 • 160 15 -31 101 -171 lh -222 92 -168 31 -49 39 -104 66 -150 55 -98 40 -52 38 -45 51 38 • 49 78 -158 72 -128 50 48 -82 23,00 -110.00 22.00 -93,00 7 .so -230.00 o. 70 -205,00 0,40 -30,00 1.50 -190,00 1.50 -98.00 9.00 -150,00 2.00 -15,00 1.50 -148.00 13.00 -140,00 2.30 -25.00 0,50 -1.80 1.00 • 2.40 o. 75 -2,20 0.75 -3,80 o. 25 -0,40 6.9 -15.0 8.1 • 16.3 0.6 -14.5 4.5 -16.4 2.0 • 15.0 2.7 -12.8 4.0 -9,7 1.8-11.8 5.4 -12.2 3.8 -11,5 2.7-11.7 2.9 -8.9 2.7-7,2 3.4 -7.9 4,G 3,3 -8.4 1.5 -9.4 1.5 -8.3 5,9 2.0 -7.0 8,8 -21.4 11.2 -26,0 3.6 • 19.8 3,0 -26.4 2,2·25.1 4.6 -24.2 5.3 -25.0 0,6 -23.4 3.0-17.6 4.2 -18.0 4.8 -15.4 4.6 -17.8 4.4 -13.6 4.1-19,2 2.9 -20.5 1.9-20.4 2.1 • 26.3 2.4 -23.8 2,4 3,4 2,3,4 2,3,4 1,3,4 IT1 I N I ~ a Table E.2.7. 1 Natrix of observed fish species and physiochemical parameters for habitat locations in the Impoundment study reach of the Susitna River, ~1ay-September, 1981 (adapted from ADF&G 1981a, c, d, f, g). Consult ADF&G for further interpretation. FISH SPECIES PHYSIOCHEHICAL PARAMETERS ] -------~-----------;-----------------------r---r------------------~-------------------------------.---4 HABITAT I.OCATIOH Susltna at Fog Creek Fog Creek -Sec. 01 Fog Creek -Sec, 02 Fog Creek -Sec. Ol Sus I tna at T susena Creek husena Creek • Sec. 01 Sus I tna at Deadman Creek Deadman Creek - Sec, 01 Sec, 02 Susltna at Watana Creek Watana Creek • Sec. 01 Sus I tna at Sec. 02 Sec. 03 Sec. 04 Sec. 05 Kosi na Creek Koslna Creek - Sec, 01 Sec, 02 Sec. 03 Sec. 04 Sec, 05 1 AOF&C 1978 ---Data not collected, Anadromou• ... .. . f tl 0 ... :i a ~ ·-~ ... &. ~ ~ 8 ~ c .... c ~ .,... +1 m c L U C:: .,.. dl ~ .!1 IJ. X X X X X X X X X X .X X X X X X X X X Resident X X X X X X X X X X X X X X X 10.1 -11.6 10.0 -11.8 10.5 -11.6 9,8 -12,2 9.9 -13.2 9,9 -11.6 9.5 -12,6 9,, -12.6 9.6-11.7 9.5 -14.1 9.8 -13.9 9.7 -n.1 10.2 -11.7 9.7 -10.6 9,0 -12.1 9,1 -12.9 ll.9 -ll.6 9.2-ll.7 9. I -13.5 9.2 -13.6 7.'1 -7.5 7.3 -7,, 7.3-7,, 7.3-7.5 6,8-7,3 7.3-7.7 7.0 -7,5 7.0-7,3 7.5-7.7 7.1 -7,7 7.3-7.7 7.3 -7.7 7.6 -7.6 7.6 -7.7 6.8 -7.5 7.1-7.5 7.1-7.5 7,1-7.6 7.1 -7,5 7 .I - 7 ·" 73-90 68 -81 68 -81 106 -107 55 -71 100 -138 44 -79 44 -79 109 -132 101 -245 101 -2U 103 -246 149 -248 156 -247 106 -146 54 -68 53 -67 54 -67 54 -67 53 -68 0.34 -1.40 0.65 -1.10 0.60 -1.50 48.00 -125.00 0.60 -1.80 51.00 -130.00 0.68 -1.80 1.50 -2.30 58.00 1,30-9,80 1.30 -9.60 3.10 10.00 -HS.OO 0.50 -1.90 0,60 -1.50 1.50 -4,40 f ~ i ... .. ~ .. o .... -~ .. fl .. 't .if 6. I -10.4 6,4 -9,4 6.4 -9.7 8.6 -10.0 7.5 -9.8 8.4 -12.6 7.6 -12.4 7.5 -12.4 8.0-11.7 1.5-11.3 1.9 -11.2 2. I -11.'1 8.3 -10.0 10.4 -11,4 3.3 -12.5 2.8 -12.3 2.7 -10.5 2.7-10.9 2.7-11.2 2.9 -11.5 ~. 16.5 -22.0 17,0-19.2 16.8 -'19,0 12.5 -14.0 13.0 -15.0 11.4 -19.0 11.4 -19.0 11.4 -15.0 14.5 -16.0 1.3-18.0 3.7 -18.0 3.8 -19,0 16.5-21.5 19.0 -21,0 5.2 -24.0 5.0 -24.0 5.4 -23.5 5.3 -19.0 5.3 -28.0 6.8 -24.5 ';;; u 'i. .c .. .... 0·~ •o-"0 .. :I ,., ... .c .. Q. ... ...... oz. :! c :·: ..... .... ... .., .. , fTl I N I ..j:::,. Tab 1 e E. 2 • 7 • Su~ i tna at Jay Creek Ja'f Creek • Sec, 01 Sec. 02 Sec. 03 Sec. 0~ Sec. OS Susitna at Coo6e Creek Goose Creek ~ Sec. 01 Sec, 02 Sec. 03 Sec. 0~ Sec, 05 Susi tna at Oshetna Ri vc r Os.hetna River ~ Sec, 01 Sec. 02 Sec, 03 Sec. 0~ Sec. 05 1 AOF&G 1978 ---Data not collected. (continued). Anadromou:r. fiSH SPECIES X X X X X X X X X X X X X X X X X J Resident X X X X X X 9. I -12.3 9.9 -13.0 10.1 -13.1 10.0-13.1 10.1 -13.0 10,1 -13,2 8.5 -12,9 8.6 -11.1 8,8 -13.6 8.9 -13.5 8.6 -13.8 8.6 -13".6 9.3 -12,3 8,9 -12,0 9.~ -12.0 9.6 -12,1 9,5 -12.0 9.6 • 12.0 7,2-7.7 7.~ -7,9 7.5-7.8 7.5 -7.8 7.6 -7.8 7.5-?.7 7.3-7.7 7.0-7,5 7.1 -7 -~ 7,0-7,4 7,0-7.~ 7.0 -7.~ 7,4 -7.6 7.2-7.6 7.2-7.6 7.2-7.6 7.2-7.6 7.2-7.6 PHYSIOCHfHICAL PARAMETERS 100 -170 12~ -175 128 -175 128 -17~ 128 -174 128 -173 100 -152 ~7 -66 ~7 -6~ ~7 -6~ 48 -M ~8 -66 101 -152 69 -135 65 -135 65 -135 65 -no 65 -132 19.00 -155.00 0.60 -2.20 0.50 -8.60 0,60 - 23.00 - 0.40 - 0,35 - 0.35 - 0.32 - 0.35 - 5.~0 155,00 2.20 o.~o I. 70 0.~0 2.60 2~.00 • 175.00 1. 20 -9,00 1.50 1.30 -19.00 1.90 1.20 -13.00 6.7-11.~ 5.7-9,7 3.6 -9.~ ~.o -8.3 ~.2-8,5 ~.3 -8.8 5.0 -13.7 5.~ -1~.~ ~.3 -12.3 ~.7 -n.~ ~.9 -H.~ 5.2 -14.6 G.l -12.3 7.0 -12,6 5.2 -10.7 5,8 -10.8 5.8 .. 11.0 6.0-11.5 10.7 -18.0 10.6 -18.0 11.0 -16.0 7.8-17,0 10.2 -2~.0 9.6 • 2~.0 6.0 -211.0 6,0 -21.5 6.2 -19,0 7.8-23.5 7.9 -21.0 7,7 -22.0 8.5 -20.0 7.8 -14.0 10,0 -18.5 10.0 -21.0 10,0 -22.5 10,0 .. 23.5 fT1 I N I ~ N -j 1 Table E.2.8. SlOUCH 8A 9 168 19 21 l 1 ~latrix of observed fish species and physiuchemical parameters for the selected habitat slough study sites of the Susitna Ri.ver, Nay-September, 1981 (adapted from ADF&G 1981a, c, d, f, g). Consult AOF&G for further interpretation. X X X X X X X X X " ·~ c !l ::1 .... ., :; . l! X X X X X FISH SPECIES* Reo! dent X X X X X X X X X " ... it .. " ! . .... ~· '1-·~ "D 't~ " ...... r: .. :l fc 4. ·~ 2,4 1,214 1,2,,,4 1,.2,3,'1 1,2,3,•t 8.8 -10.5 10.6 • 11.4 10.8 -11.7 9.4 -10.4 10.1 -11.3 6.8 -1.6 6.8 -7.4 6.l! -7.1 6.5 -2.3 7.0-2.7 PHYSIOCIIEHICAL PARAMETERS** 108 -160 111 -145 6ft -72 121 -150 103 -226 o. 70 -205.00 0.60 -130.00 0.50 -43.00 O.ltO -2.50 O.ltO ~ 150.00 I l 4.5 -16,1t 5.6 -14.2 4.8 -14.0 1.8 -9.8 2.4 -11.3 " L " .... :! ft .... L ::;: 3,0 -26,1t 7 .s -20,1 l~ 0 ·~ ·~ '0 .. " ..... .1:.14 ... .... ... .. 0 .. a. fl c <=·~ .. .... ...... L IJ ...... 2,4 2,1t 2,3,4 2,3,4 2,4 * 1981 fishery dah for juvenile anadromous and resident fhh species were not collected in Sloughs 9, 168, 19, and 21. ** Physiochemical data for Sloughs 9, Hi8, 19, and 21 are based on throe oampllng vhtta. Slough BA was sampled on a routine bnh as a habitat location. ~ ADF&G 1974 AOF&G 1976 ~ AOf&G 1977 AOF&G 1978 reaches of the river suggest that a greater diversity of habitat types or more favorable conditions are present in the downstream portion of the river. This however does not infer that the existing habitats in the impoundment study area cannot support anadromous fish populations. Several trends in physio- chemical characteristics are also apparent: e.g. specific conductance values are usually higher in the mainstem than in slough or tributary study sites; pH values are higher in the impoundment study reach than in other study reaches. 2.7 Chum and Sockeye Adult Salmon Observations in Selected Sloughs in Relation to Mainstem Discharge Surveys of spawning grounds in the Susitna River and its sloughs were conducted by AA personnel to enumerate adult salmon in these areas (Table E.2.9). Table E.2.9 compares chum and sockeye salmon enumeration at Sloughs* 8A, 9, 98, 19, and 21 (Figure E.2.20) with discharge data for the mainstem Susitna River at Gold Creek on the same day. These sloughs were selected for comparing hydrologic characteristics with spawning activity because physiochemical characteristics were evaluated in greater detail at these locations than at other study sites. Additional discussions of these areas are presented in Chapters 3 and 4 and the AA, AH, and RJ subject reports (ADF&G 1981a, c, d, f). When mainstem flow is too low to enter the head (upstream end) or mouth {downstream end) of a slough {values which are unique * Sloughs, as defined in this study, are the side channel or adjacent wetted habitats to the mainstem Susitna River which periodically receive a portion of their surface water from the rna in stem Susitna River in addition to other water sources (e.g. groundwater. intragravel and surface water). The contribution of the mainstem Susitna River to the surface water flow in each slough can vary from 0 to nearly 100% depending on the Susitna River stage/discharge relationship to the thalweg of the slough. E-2-43 - - - - - -· - Table E.2.9. Comparison of adult sockeye and chum salmon escapement counts for Sloughs 8A, 9, 98, 19, and 21 (ADF&G 1981a) to Susitna River discharge data (cfs) at Gold Creek (USGS 1981). ,- Slough 8A Survey Susitna River Date Sockeye Chum Conditions Discharge 810807 0 16 Excellent 26,200 810820 0 0 Poor 34,200 810827 0 0 Poor 24,200 810904 177 620 Excellent 16,600 810912 105 311 Excellent 14,100 810921 38 7 Excellent 12,200 810927 9 0 Excellent 8,890" Slough 9 Survey Susitna River Date Sockeye Chum Conditions Discharge 810807 0 0 Poor 26,200 810811 0 5 Fair 43,500 810820 0 0 Poor 34,200 810823 0 0 Excellent 37,900 -810827 24,200 810904 10 260 Excellent 16,600 810916 6 71 Excellent 14,100 810920 10 16 Excellent 11,400 810927 0 2 Excellent 8,890 Slough 98 Survey Susitna River Date Sockeye Chum Conditions Discharge 810807 26,200 810811 27 58 Excellent 43,500 810820 34,200 810823 47 90 Excellent 37,900 810827 81 71 Excellent 24,200 810904 71 49 Excellent 16,600 810916 62 26 Excellent 14,100 810920 54 7 Excellent 11 ,400 810927 35 0 Excellent 8,890 ---Data unavailable. E-2-44 - Table E.2.9 {Continued). - -· Slough 19 Survey Susitna River Date Sockeye Chum Conditions Discharge 810806 0 0 Excellent 27,500 810810 0 a Fair 42,600 - 810821 13 3 Excellent 41,300 810826 20 0 Excellent 25,600 810903 23 1 Excellent 18,300 810911 18 0 Excellent 14,300 810919 8 0 Excellent 10,500 810926 6 0 Excellent 9,560 """ ! "'""': Slough 21 Survey Susitna River -Date Sockeye Chum Conditions Discharge 810806 0 0 Poor 27,500 810810 0 0 Poor 42,600 -810821 0 0 Poor 41,300 810826 1 169 Excellent 25,600 810903 26 274 Excellent 18,300 ~ 810911 38 136 Excellent 14,300 810919 33 67 Excellent 105500 810926 3 0 Excellent 9,560 - - - E-2-45 ,- - - - I Devil Canyon : 7 Rivermiles Fourth oC July Creek ""'( Slough 19 Sherman Creek Indian River Creek \ Talkeetna: 26 Rivermileil Figure E.2.20. Location of selected habitat slough sites along the Susitna River between Talkeenta and Portage Creek (adapted from ADF&G 1981a) E-2-46 for each slough), surface water influence from the mainstem is effectively eliminated and clear water base fl ovJs are still observed in the sloughs. These base flows could originate from various. sources, including tributaries, springs and groundwater inflow. Spring water could be fed by a perched water table or from interstitial flow (flow of water through spaces in the substrate) from the mainstem. Sloughs 8A, 9 and 21 have tributaries contributing water to the base flow. Slough 19 originates from a large spring at its head (upstream end). Sloughs 19 and 21 also have many areas of upwelling throughout the stream bed, and Slough 21 has water seeping in along the edges during periods of falling discharge of the mainstem Susitna River. Observations of fish activity in these sloughs indicate that they provide the most important salmon spawning habitat of the Susitna River habitats evaluated during 1981 between Devil Canyon and Talkeetna (ADF&G 198la, c). Peak spawning activity of sockeye salmon was observed to occur in the sloughs during the last week in August and the first three weeks of September (ADF&G 1981a). Chum salmon peak spawning activity occurred during the last two weeks of August and the first two weeks in September. Counts of spawning activity were highest for chum salmon in Slough SA and highest for sockeye in Slough 11. One factor contributing to the large numbers of salmon spawning in these sloughs may be the availability of holding areas at the mouth of the sloughs in proximity to suitable spawning substrate within the main channel of the sloughs. The level of spawning activity in Sloughs 9 and 9B (Table E.2.9) may be attributed to the availability of spawning substrate as wel1 as flows sufficient to provide access into the mouths of these sloughs from the mainstem Susitna River. Flow levels in these two sloughs are augmented by E-2-47 - - - - - - - - - - - - - - - tributaries which contribute to the availability of suitable habitat within the sloughs when the mainstem flow of the Susitna River decreases. The limited spawning activity observed in Slough 19 (Table E.2.9) may be due to limited access during lower flows of the mainstem Susitna River and to lack of spawning substrate. During low discharges of the mainstem Susitna River, access to the mouth of Slough 19 was limited to a depth of 0.3 feet on September 26 when mainstem Susitna River discharge at the Gold Creek station equalled 9,560 cfs. At high mainstem Susitna River discharges, a backwater forms at the lower end of this slough. The deep deposits of silt near the mouth of Slough 19 are characteristic when streamflows are insufficient to flush fine sediments from this slough. The absence of spawning salmon suggests that these deposits of deep silt are undesirable as spawning substrates. The relatively high number of spawning chum salmon and sockeye observed in Slough 21 {Table E.2.9) may be primarily due to suitable spawning substrate and maintenance of flows. These flows are maintained by groundwater and tributaries, and provide adequate spawning habitat when mainstem flows of the Susitna River are too low to flow into the slough. Spawning activity was observed to peak long after mainstem flow of the Susitna River was completely restricted from entering the head portion of the slough. {The flow within Slough 21 is compared to corresponding mainstem discharges in Table E.5.7 of the ADF&G subject report, ADF&G 198lc). E-2-48 - 2.8 Fisheries and Habitat Relationships in the Proposed Impoundment Area 2.8.1 Introduction This section compares data on Arctic grayling and habitats in eight major - clearwater tributaries located in the study area upstream of Devil Canyon (Impoundment reach) by RJ and AH personnel during the 1981 open water field season.* Data from each tributary were collected between the tributary mouth and the proposed impoundment elevations, PIE of the Watana (2185 ft msl) and Devil Canyon (1455) Reservoirs (Figure E.2.21). Habitat study locations and miscellaneous sampling site areas are i 11 ustrated in Figure E. 2.21. Deta i 1 ed habitat descriptions of these study areas are presented in the AH and RJ - subject reports {ADF&G 1981c, g). 2.8.2 Water Quality Water quality data collected in the Impoundment study reach are presented in Table E.2.7 {See Section E.2.6). No major differences are apparent in the range of water quality data from various sites which might influence grayling distribution and abundance in tributaries and the mainstem Susitna River. Although increased turbidity levels in the Oshetna River, Jay Creek and Watana Creek were at times associated with lower catch per unit effort, CPUE (Tables E.2.10 and E.2.11) and total catch (Table E.2.12), population estimates remained relatively high for the Oshetna River and Jay Creek (Table E.2.13). * Arctic grayling were selected for analysis because of their importance as a sport fish and the availability of sufficient data on this species. E-2-49 - - - - - - - - - ~ Miscellaneous Habitat Study Site Iii Habitat Location Sampling Site ---Proposed Impoundment Elevation ver Susitna Rl Figure E.2.21. Sampling design for identifying habitat location and miscellaneous fish habitat study sites in the Impoundment study reach tributaries. E-2-50 Table E.2.10. Arctic grayling hook and line catch and effort at habitat location sites in the lower mile of each tributary in the Impoundment study area, 1981 (adapted from ADF&G 1981g). TRIBUTARY HABITAT LOCATION Ma~ June Jull August seet. TOTAL Fog Creek Total Catch 14.0 17.0 11.0 4.0 5.0 51.0 Man Hours 1.8 3.9 2.6 1.8 2.5 12.5 CPU£ 8.0 4.4 4.3 2.3 2.0 4.1 Tsusena Creek Total Catch 23.0 19.0 74.0 18.0 1.0 135.0 Man Hours 5.0 3.4 8.3 5.5 0.5 22.6 CPUE 4.6 5.6 8.9 3.3 2.0 6.0 Deadman Creek Total Catch 53.0 69.0 27.0 4.0 0.0 153.0 Man Hours 7.5 9.0 3.5 2.2 1.4 23.6 CPUE 7.1 7.7 7.7 1.8 0.0 6.5 Watana Creek Total Catch 1.0 29.0 14.0 5.0 10.0 59.0 ~1an Hours 3.3 5.4 4.3 2.0 3.1 18.1 CPUE 0.3 5.4 3.3 2.5 3.3 3.3 Kosina Creek Total Catch 119.0 79.0 87.0 17.0 33.0 335.0 Man Hours 16.6 7.3 6.8 3.0 2.8 36.5 CPUE 7.2 10.8 12.8 5.7 12.0 9.2 Jay Creek Total Catch 3.0 49.0 64.0 13.0 47.0 176.0 Man Hours 2.4 5.4 7.3 2.9 5.5 23.4 CPUE 1.3 9.1 8.8 4.6 8.6 7.5 Goose Creek Total Catch 121.0 76.0 36.0 32.0 2.0 267.0 r~an Hours 16.3 12.3 4.5 7.4 2.4 42.9 CPUE 7.4 6.2 8.0 4.3 0.8 6.2 Oshetna Creek Tota 1 Catch 4.0 43.0 50.0 46.0 7.0 150.0 ~ian Hours 2.2 4.8 7.7 5.1 3.4 23.2 CPUE 1.8 9.1 6.5 9.0 2.1 6.5 TOTAL TOTAL CATCH 338.0 381.0 363.0 139.0 105.0 1,326.0 MAN HOURS 55.1 51.3 45.0 29.9 21.6 202.8 CPUE 6.1 7.4 8.1 4.6 4.9 6.5 E-2-51 ~ - - """' - """' - - ~ - - - - - F" - - ~ - - Table E.2.11. Arctic grayling hook and line catch and effort at miscellaneous fish habitat sites* betvJeen the mouth and proposed impoundment elevations (PIE) at each tributary in the Impoundment study area, 1981 (adapted from ADF&G 1981g). MISCELLANEOUS FISH HABITAT SITES Tributary 1st Mile Fog Creek Tota 1 Catch 21.00 Man Hours 4.16 CPUE 5.05 Tsusena Creek Total Catch t~an Hours CPUE Deadman Creek Total Catch 37.00 t~an Hours 5.07 CPUE 7.30 ~Jatana Creek Total Catch 21.00 Man Hours 4.50 CPUE 5.19 Kosina Creek Total Catch 57.00 Man Hours 11.46 CPUE 4.92 Jay Creek Total Catch 60.00 ~1an Hours 6.35 CPUE 9.45 Goose Creek Total Catch 64.00 Man Hours 8.49 CPUE 7.54 Oshetna River Total Catch 59.00 Man Hours 7.91 CPUE 7.46 TOTAL TOTAL CATCH 319.00 MAN HOURS 47.50 CPUE 6.70 * Does not include fish habitat location sites. ** PIE for Fog and Tsusena Creeks = 1455 ft; all others = 2185 ft. ---Data unavailable. E-2-52 Above Mile 1 to PIE** 186.00 19.56 9.51 357.00 32.16 11.10 81.00 7.41 10.93 51.00 6.16 8.28 297.00 22.07 13.96 972.00 87.41 11.12 Table E.2.12. Arctic grayling hook and line total catch by tributary between the mouth and proposed impoundment elevations {PIE*) and month in the Impoundment study area, 1981 (adapted from ADF&G 1981g). CATCH TRIBUTARY MAY JUNE JULY AUGUST SEPTE~iBER TOTAL Fog Creek 22 17 23 5 5 72 Tsusena Creek 23 19 74 18 1 135 Deadman Creek 53 86 42 6 3 190 Watana Creek 1 49 16 172 28 266 Kosina Creek 136 246 143 67 187 779 Jay Creek 3 178 70 16 50 317 Goose Creek 121 136 82 37 6 382 Oshetna River 19 92 155 73 167 506 TOTAL CATCH 378 823 605 394 447 2,647 * PIE for Fog and Tsusena Creeks= 1455 ft; all other tributaries= 2185 ft. E-2-53 - - - - ~ ~ - .... - ·~ - - - ..... - - - Table E.2.13. Arctic grayling population estimates for tributaries in the Impoundment study area, 1981 (adapted from ADF&G 1981g).* POPULATION CONFIDENCE** STREAM ESTIMATE INTERVAL Fog Creek 176 115-369 Tsusena Creek 1,000 743-1,530 Deadman Creek 979 604-2,575 Kosina Creek 2,787 2,228-3,720 Jay Creek 1,089 868-1,462 Goose Creek 1,327 1,016-1,913 Oshetna River 2,017 1,525-2,976 * Watana Creek estimate is not included because the number of recaptures was too low. ** Based on June through September recoveries. E-2-54 Therefore, the lower catch values most likely resulted from the reduced effectiveness of hook and line sampling in turbid water. Grayling recaptures in Watana Creek were insufficient for calculating the population. Grayling distribution and abundance in the Impoundment reach appeared to be closely associated with surface water temperature. As water temperatures in the tributaries increased in the spring, increased numbers of grayling were observed migrating upstream into areas having pool type habitats [presumably after spawning in the lo\'1er reaches of the tributaries, (Morrow 1980)]. Tagging studies indicate that a large number of these fish continued to utilize these areas for rearing into the summer. As surface water temperatures began to decrease in the late summer and early fall, lower numbers of fish were observed in these upper stream habitats. CPUE also decreased in most of these areas and tagged fish were observed to be migrating downstream. The large decline in total catch (Table E.2.12) and lower CPUE levels (Table E.2.10) in late summer and early fall indicate that fewer fish were present. In small shallow streams such as Goose and Jay Creeks, grayling began moving downstream earlier in the season. Lower numbers of fish were captured in these smaller streams in the late summer. Conversely, fish were observed in the larger streams (e.g. Oshetna River and Kosina Creek) up until late September, at which time it appeared as though a downstream migration of the grayling was beginning. Thermographs were not placed in these streams, and continuous water temperature records are not available for correlating specific water temperatures with grayling migrations on different streams. E-2-55 - - - - - - - - - -· E-2-56 -------------- - ~"""" I ' ' Installation of thermographs and intensive sampling at selected sites in 1982 may help substantiate these observations. 2.8.3 Substrate Substrate composition at the habitat evaluation sites in the lower mile of each tributary in the Impoundment study area are presented in Appendix EA of the AH subject report (ADF&G l981c). Substrates in the 1 ower mile of each tributary appear to be similar to the composition of substrate in the reach above the lower mile up to the PIE. Therefore, substrate data presented for the lower mile of each tributary appears to be representative for that particular tributary up to the PIE (Watana Creek cannot be included in this evaluation because it was not assessed above the lower mile). Grayling have been observed to spawn over a wide variety of substrates with a preference for sandy gravel (Morrow 1980). Although spawning has not been observed in the Impoundment reach, it probably occurs to some extent in a 11 eight tributaries sampled, since suitable spawning habitat has been observed in each stream. Assuming other conditions for spawning are favorable, it is not likely that the availability of spawning substrate is the limiting factor influencing grayling numbers in the upper Susitna and its tributaries. Substrate relationships to food production (Reiser and Bjornn 1979) are probably more important in influencing grayling distribution in these tributaries. E-2-57 ~~~-------------- - - - - - - E-2-58 - ~ Q) Q) s... u >, rU 'J s... Q) 3: 0 ...t:: Vl 4- 0 s... +-' u Q) ....... w <;;t Q) +-' ctl ....... 0... 2.8.4 Streamflow and Channel ~1orphology Streamflow and channel morphology may be the most important habitat character- istics in determining grayling distribution and abundance in the Impoundment study reach. High pool/riffle ratios with large deep pools and moderate streamflow velocities appear to indicate preferred grayling habitat. Higher CPUE occurred where these conditions were observed. In the impoundment reach~ 1 arge deep streams such as the Oshetna River and Kosina Creek appear to provide optimal fish habitat. Population estimates listed in Table E.2.13 support this evaluation. Kosina Creek, in particular, has a relatively high pool/riffle ratio and contains many large deep pools which may be used as overwintering habitat. Goose and Jay Creeks, which also have relatively high population estimates, are shallower and smaller than Kosina Creek and the Oshetna River, and do not appear to have suitable overwintering habitat. In contrast to these streams~ lower Deadman and Tsusena Creeks are characterized by few pools and long reaches of whitewater. The only habitat which might be suitable for overwintering in either of these creeks are the few pools located below their falls. With the exception of Fog Creek, which was one of the smallest areas studied in the Impoundment reach (Table E.2.13), population estimates were lowest in these two streams. t~ean column water velocities were measured near observed grayling during the 1981 season. Based on both visual observations of fish and CPUE in habitats where streamflow velocities in this range were measured, provisional data E-2-59 - - - .... - - E-2-60 - indicate that grayling may prefer to reside in habitats where mean column velocities are less than 2.0 ft/sec. Hook and line sampling may have biased the data because it proved to be an ineffective capture method in higher velocities. Accurate visual observations were not possible in areas of high streamflow velocities. 2.8.5 Conclusions With one year of limited data it is difficult to determine quantitatively the relationship between aquatic habitat and the distribution and abundance of grayling in the eight major tributaries in the study area. Data limitations include: 1. each of the streams in the study area was only sampled approximately two days per month and many of the habitat characteristics measured will have to be monitored more extensively to accurately assess fisheries habitat, and 2. with respect to fisheries data, there is a certain amount of bias associated with the primary method of capture (hook and line). In some cases, such as in areas with high turbidities, alternative fish capture techniques may improve catch rates. Keeping these limitations in mind, some preliminary conclusions derived from the 1981 data are: E-2-61 1. changes in water movements in and respectively; temperature appeared to influence grayling out of streams in spring and late summer 2. grayling were genera11y more abundant in habitats with streamflow velocities below 2.0 ft/sec; 3) channels with large deep pools and/or cutbanks appeared to provide optimal habitat, large numbers of grayling were found in these areas; and, 4) availability of spawning substrate did not appear to significantly limit grayling distribution and abundance in the study area. E-2-62 Plate 6. Confluence of Susitna River and Kosina Creek in the impoundment study reach, showning mixing of clear and turbid waters. - 3. HMITAT R£LATION9HPS ,... - - - - - - - 3. HABITAT RELATIONSHIPS 3.1 Introduction This chapter discusses the relationships among specific physical aquatic habitat parameters. The data used in developing these relationships were originally reported in the AH, RJ and AA subject reports (ADF&G 1981a, b, c, d, f). Included in this chapter are descriptions of how several physiochemical parameters are related to discharge. These relationships can potentially be affected by the proposed development of the two dams. 3.2 Discharge and Turbidity Relationships Relationships between mainstem Susitna River discharge {USGS 1981) and turbidity in the mainstem and sloughs (ADF&G 1981c) are shown in Figures E.3.1 -E.3.4. Figures E.3.1 and E.3.2 illustrate the relationships between mainstem discharge measured at Gold Creek and turbidity in selected mainstem and slough sites, between Talkeetna and Portage Creek. Figures E.3.3 and E.3.4 illustrate the relationship between mainstem discharge measured at Sunshine and turbidity in selected sites from the mainstem and sloughs, below Talkeetna. Mainstem Susitna River turbidity generally increases with mainstem discharge {Figures E.3.1 and E.3.3). Slough turbidity remains low as mainstem discharge increases until a certain threshold mainstem discharge level (unique for each slough) is attained; at that point, the turbidity in the slough rapidly increases and mirrors the turbidity and discharge relationships characterizing the mainstem (Figures E.3.2 and E.3.4). These relationships E-3-1 250 200 ....... ::;) 1- z 150 ..... rTJ I >-w I 1- N c 100 m a: :::> 1- 50 0 5 o Malnatem 2 • Melnatem at Curry 6 Susltne Side Channel 4 Su~ltna Gravel Bar 0 Malnatem lnalde Bend 8 Malnatem Island 0 10 15 • 6 4 0 0 20 • • ~ D. 0 • 0 25 30 35 40 SUSITNA DISCHARGE AT GOLD CREEK ( C F S X 1 0 0 0) 0 0 Figure E. 3 .1. Mainstem turbidity (Talkeetna to Portage Creek reach) versus mainstem discharge of the Susitna River at Gold Creek (adapted from ADF&G 1981c and USGS 1981). 0 • 45 50 250 ..... 200 :::> 1- z ...., 160 >- ITl 1- I w I c 100 w m a: ::l 1-60 0 5 J • Slough OA 0 Slough 8A & Slough 8 A Slough 10 0 • Slough 11 0 Slough 188 X Slough 10 * Slough 20 till Slo.ugh 21 ®=O&OXI<il * 1<11 t=O&A + A * 0 A 0 A • * lit>~. e • .®. 0 'JI )lM 10 16 20 26 30 36 40 45 SUSITNA DISCHARGE AT GOLD CREEK (CFS X 1000) F i g u re E. 3 . 2 . Slough turbidity (Talkeetna to Portage Creek reach) versus mainstem discharge of the Susitna River at Gold Creek (adapted from ADF&G 1981c and USGS 1981. • 60 -::J 1- z - >- 1- fT1 0 I w I m .;:;. a: ::> ..... 300 e Lower Dalla Iaiande 0 Rutlla Wlldarnau ... Malnalam Watt Bank 250 .6. Malntlam 1 200 150 100 50 0 20 30 Figure E.3.3. • .6. ... • 0 0 40 50 60 70 80 90 100 SUSITNA DISCHARGE AT SUNSHINE (CFS X 1000) Mainstem turbidity (downstream of Talkeetna) versus mainstem discharge of the Sunshine River at Sunshine (adapted from-ADF&G 1981c and USGS 1981}. J 110 300 250 ...... ::> 200 1- z ..... >-150 t- rn I c w I Ul m 0: 100 ::> 1- 50 0 e Kroto Slough Mouth 0 Mld-Kroto Slough A Malnatem Slough A Slough Weal Bank • Sheep Creek Slough 0 Gooee Creek Slough X Birch Creek Slough * Cache Creek Slough * A * • 0 • A A !i. X 20 30 A 0 • 40 SUSITNA * 0 * 0 • * 0 0 )( * A 0 i' ,. )( • • •• 60 60 70 80 90 DISCHARGE AT SUNSHINE (CFS X 1000) Figure E.3.4. Slough turbidity (downstream of Talkeetna) versus mainstem discharge of the Susitna River at Sunshine (adapted from AOF&G 1981c and USGS 1981). * i 8 • )( • 100 110 are more easily observed in the reach of the Susitna River between Talkeetna and Devil Canyon than in the reach between Cook Inlet and Talkeetna. Some sloughs (e.g., Sloughs 6A and 19) retain low turbidities even at high mainstem discharges due to localized conditions, e.g. clear water influx or no upstream connection with the mainstem Susitna River*. Turbidity patterns at Slough 10 are similar to those in the mainstem because samples were actually collected in the mainstem at or below the slough mouth. Figure E.3.5 illustrates changes in mainstem Susitna River turbidity from June through September 1981 at four sites: below the Deshka River (R.M. 31.0), above the Parks Highway Bridge (R.M. 84.0), above Gold Creek (R.M. 136.9), and above Jay Creek (R.M. 203.9). The points are connected to facilitate comparisons between sites; however, it should be noted that few points are plotted and that large variability may occur in turbidity for the time frame shown. Generally, turbidity levels increase with increases in discharge and this trend is followed throughout the length of the river (Figure E.2.1 and Figure E.3.5). Additional data will be required to represent the various peaks in discharge which were not represented with these data. Sites should be sampled more frequently to better define the discharges at which sloughs are affected by mainstem surface water influx and to determine if a difference in turbidity exists between rising versus falling discharge levels. Samples should be collected in both the mainstem Susitna River near the slough and within the slough. * See Section 2.7 and Chapter 4. E-3-6 - - - - - 240 200 160 .-. ::> t-z '-' >-t-120 0 iii a: f1l ::> I 1-w I 80 ........ 40 6/18 6/30 F i g u re E. 3 . 5 . .. q .. .. .. .. 7/18 7/30 8/15 . \ . . .. . . ..... , o~~~~ .. 8/30 DATE (1981) -i --.. ] 0 • • • • .. o Below Deshka River, A.M. 31.0 •·-........ Above Parks Highway Bridge, A.M. 84.0 l::s·-·-·-6 Above Gold Creek, A.M. 136.9 o-----o Above Jay Creek, A.M. 203.9 'o 9/5 9/20 9/29 Mai nstem turbidity of the Susitna River as a function of time at the following sites: below Oeshka River (R.M. 31.0); above the Parks Highway Bridge (R.M. 84.0); above Gold Creek (R.M. 136.9) and above Jay Creek (R.M. 203.9). 3.3 Differences Between Surface Water Temperatures at Mainstem Locations Biweekly mean daily surface water temperatures of the mainstem Susitna River at 11 sites between Alexander Creek (R.M. 10.0) and Devil Canyon (R.M. 152.0) are listed in Table E.3.1 for the period from June 20 through September 27, 1981 (ADF&G 1981c). These data were used to construct temperature profiles for the mainstem Susitna River (Figures E.3.6 -£.3.13). Surface water temperatures for the Sus i tna River show significant variabi 1 i ty upstream to downstream. This may be due to the effect of major tributaries (such as the Chulitna, Talkeetna and Yentna Rivers) on the temperature regime of the Susitna River. Inflow from these tributaries may also buffer Susitna River temperatures. Higher winter temperatures are predicted for the reach of the Susitna River between Talkeetna and Devil Canyon if the dams are built (Acres 1982). Inflows from the Chulitna9 Talkeetna, and Yentna Rivers may therefore buffer this temperature alteration downstream from the respective confluences. Additional data will be collected in 1982 to better define the relationships between the Chulitna, Talkeetna, Yentna, and mainstem Susitna River temperatures and to predict the influence of post-project temperatures downstream of Talkeetna. 3.4 Diel Surface Water Temperature Fluctuations Water temperatures in the Susitna River drainage fluctuate on both a temporal and spatial basis. Variations in temperature over a 24 hour period are referred to as diel fluctuations. Water temperature data for selected thermograph sites (see ADF&G 198lc) were plotted (Figures E.3.14 to E.3.15) to show diel fluctuations at representative sites. The plots show the one week E-3-8 - - - .... - .... rr1 I w I '-0 1 Table E.3.1. ~1ainstemSusitna River surface water temperatures, oc (AOF&G 1981c), for various sites used in developing Figures E.3.6 to E.3.13. DATE (1981) rl rl co LO s.... rl N QJ 0 0 co m ..c RIVER ('J M rl N +"' +"' E til til QJ MAINSTEM SITE MILE QJ QJ >, >, :::1 :::1 +"' c: c: ..... ..... Cl Ol 0.. :::1 :::1 :::1 :::1 :::1 ::I QJ r-::1 r-::1 r-::1 r-::1 <( <( Vl ·TEMPERATURE Above Alexander Creek 10.1 10.1 7.1 8.6 8.1 7.1 7.1 Above Yentna River 32.3 13.4 8.5 11.1 10.5 8.2 9.5 Above little Willow Creek 50.5 7.8 10.0 9.4 7.3 8.7 6.9 Above Kashwitna River 61.2 7.3 Above Montana Creek 77.5 12.6 7.7 10.3 Sunshine (Parks Highway Bridge) 83.3 13.3 8.1 Talkeetna Base Camp 103.0 13.6 8.5 8.1 9.2 8.4 Above Fourth of July Creek 131.8 12.8 5.5 10.2 10.6 6.8 7.6 7.4 Above Gold Creek 136.8 9.3 6.9 8.5 6.3 Above Indian River 138.7 9.1 8.1 6.2 7.5 6.5 Above Portage Creek 148.8 10.0 10.1 7.1 9.6 7.3 ---Data unavailable. r-... N s.... QJ ..c E QJ +"' 0.. QJ Vl 2.4 2.6 2.4 5.4 1.8 2.5 0.2 1.2 1.4 - OL-£-3 - TEMPERATURE ( °C) --0 en 0 01 .... , I . f <..C c: -s ro ABOVE ALEXANDER CREEK !-0 I"T'' (AM 10) . w . 0"\ ~ ABOVE YENTNA RIVER ~ 0 Vl:S:: [AM 29) c: ro VIQ.l .-.::s M-::so.. Q,JQ,l ABOVE LITTLE WILLOW CREEK ..... :::0 --' (RM 50) --·'< < r.l3 .... '"'SQ.> ...... --t,::S ABOVE KASHWITNA RIVER ~ 0 VI -s M-(AM 61) ro C....3 -!:: ::SVI roc: -s ABOVE MONT ANA CREEK 1-0 N--t, OQ.J (AM 78) ... (") en ro ...... :::j 1.0::£ m OOQ.J ...... M-SUNSHINE (PARKS BRIDGE) 1-0 ro -s (AM 84) M-ro 3 "0 ro TALKEETNA BASE CAMP '1-0 -s .-Q.J (F!M 103) M- !:: -s ro 0 ~ "0 ABOVE 4th OF JULY CREEK ~ ~ 0 -s 0 (RM 131) ::> ......, .. iD 3 ro -1 -ll> ......, I 3 0 ABOVE GOLD CREEK '0 -s (RM 137) ll> .. ~ M-c: :::r .. ro ll> ... ABOVE INDIAN RIVER 1-~ (AM 139) c.. c ::> Cll -~ .o -ABOVE PORT AGE CREEK 10 (X) (AM 149) - ------------------------- ll-£-3 TEMPERATURE ( OC) -... ... 0 "' 0 c.n , . I I' ...... 1.0 s::: ABOVE ALEXANDER CREEK 0 -s ~ ro (RM 10) I'T1 .... . w ....... ABOVE YENTNA RIVER 0 '(RM 29) tl'l::S:: S:::C'D VIPJ ...... ;::::~ rl" 0 ;::10.. ABOVE LITTLE WILLOW CREEK ~ PJPJ (RM 50) ...... ;;c __, ...... '< < C'D3 -s PJ ABOVE KASHWITNA RIVER ~ ...... -t,;::l (RM 61} OVI "'Sri" C'D C.....3 s::: ;:I VI C'DS::: ABOVE MONT ANA CREEK too 0 -s (RM 78) w-+> OPJ en .. n =i C'D m """' ...... I.O:E OOPJ SUNSHINE (PARKS -BRIDGE) 1-0 ...... rl" . ro (RM 84) -s rl" C'D 3 "'0 TALKEETNA BASE CAMP 1-0 C'D (J:!M 103) -s PJ rl" s::: 0 -s ro ABOVE 4th OF JULY CREEK !: 0 II> "'0 (RM 131) 5' -s "' 0 ; -+> 3 ...... -1 ~ C'D 3 -+> ABOVE GOLD CREEK . ~ fRM 137) ... 0 ~ -s = rl" a; "' ;:I" 0 ro :::0 -ABOVE INDIAN RIVER . .._ (RM 139) c: :::0 <1> Co> p -· ABOVE PORT AGE CREEK ~ ~ (RM 149) ZL-£-3 '""' TEMPERATURE (O·C) ... -0 t7l 0 01 -...., I t,Q c ABOVE ALEXANDER CREEK · Ia-0 -s (1) [AM 10) rrJ w 00 Ia-ABOVE YENTNA RIVER 0 [AM 29) c.n:::s:: c ro VIQ.J -'•::S M- Ia-0 ::so.. ABOVE LITTLE WILLOW CREEK Q.JQ.J (RM 50) ;;o _. -'·'< < rD3 --:;Q.J ABOVE KASHWITNA RIVER '" -+.::S (AM 61) OVI -se-t-ro C...3 c ..... (/) '<c ABOVE MONTANA CREEK !--s (AM 78) 1-' -+> ...... Q.J Ch .. n :::j ro m 1-' ~::E: ~ COQ.J SUNSHINE {PARKS BRIDGE) 1-' c-1" (RM 84) . (1) -s i!ii.i!alM M-ro 3 TALKEETNA BASE CAMP Ia-"'C ro [RM 103) -s Q.J c-1" c ®:) -s ro ABOVE 4th OF JULY CREEK .3:3: 0 "'C (RM 131) II> Ill -s 5"5' 0 "'"' -+> (DC) ...... 33 ..... -!-1 ro <DCD ~ -+> ABOVE GOLD CREEK • 33 (RM 137) '0'0 0 CD<D ...... -s IIlii> c-1" s;s; :::T CDCD ro ,.., .. -ABOVE INDIAN RIVER ~ 00 ® (AM 139) :::!:::! t..t.. c:c: -<-< 1\)--9~ ASOVE PORT AGE CREEK Ia-coco 0 CAM 149) OOCX> 'iii.'M .... ..,., ...... <.0 c ABOVE ALEXANDER CREEK ""'S (1) tAM 10J I"T'' . w 1.0 ABOVE YENTNA RIVER lAM 29) Vl3: s::: l'tl t/) ~ -'•=' M" ABOVE LITTLE WILLOW CREEK ::lO. ~~ {AM 50) ...... :::0 ....... -'•'< < (1)3 ""'S~ ABOVE KASHWITNA RIVER ...... -+!::l (AM 61) OVl ""'SM" l'tl C-.3 s::: ....... t/) '<S::: ABOVE MONT ANA CREEK ""'S (RM 78) N -t, (/) 1.0~ ~ ~ n l'tl m ..... 1.0~ [PARKS BRIDGE) co~ SUNSHINE ..... M" (AM 84) l'tl ""'S M" l'tl 3 TALKEETNA BASE CAMP "'0 l'tl (RM 103) ""'S Ql M" c ""'S l'tl "'0 ABOVE 4th OF JULY CREEK (RM 131) ""'S 0 -+> ...... l'tl ABOVE GOLD CREEK -+> {RM 137) 0 -s c-r :::::s- l'tl ABOVE INDIAN RIVER (RM 139) ABOVE PORT AGE CREEK (RM 149) 0 ~ ""' ~ ~ ~ 0 5:: 1-~. :l "' g 3 -1 (I) 3 '0 (!) ... "' E' ... (I) "' 0 !-:l c.. =. '< I\:) .fCI .... «l DJ ...., TEMPERATURE {'OCJ "' .... 0 • 0 0 0 0 0 0 0 .tn ' - i ' Md ' I - """" - """' - - vt-E-3 - TEMPERATURE ( OC) ~ --0 0'1 0 0'1 I -..,., ~ 0 ABOVE ALEXANDER CREEK t.O {RM 10) s::::: I -; rD rrl . w ABOVE YENTNA RIVER ~ 0 ,_. (RM 29) 0 . (.1) 3: 0 s:::::ro ABOVE LITTLE WILLOW CREEK Vl Q.J CAM 50) -'•:::S ~ rl" ::so.. Q.JQ.J ...... :::c ...... -'•'< ABOVE KASHWITNA RIVER 1-< (RM 61) rD3 ...... -;Q.J ...... -t,;::s OVl -;rt rD ABOVE MONTANA CREEK ::r:-3 {RM 78) s::::: en lC Vl s:::::s::::: ~ Vl-; m rt....., Q.J ,_. (") SUNSHINE (PARKS BRIDGE) ~ tJ'T(O (RM 84) ::e: ,_. Q.J L.O rt COrD ...... , . rl" TALKEETNA BASE CAMP 1-0 rD (RM 103) 3 "'C 0 rD ~ -; 3:::: Q.J '" rt ABOVE 4th OF JULY CREEK s· 0 s::::: CRM 131) .. -; e-rD 3 "'C -i II> -; 3 0 "t:l ....., ABOVE GOLD CREEK (!) 0 CRM 137) ; E" rD ., _. II> ....., "' 0 0 -; = rt ABOVE INDIAN RIVER ")> 0 CRM 139) c ::r cc .... rD c· ~ -,0'1 -0 ABOVE PORT AGE CREEK r ~ (RM 149) I - - SL-£-3 TEMPERATURE (OC) 0 01 0 0'1 'l'dl1 "'T'T 1 I ...... tO c -s ABOVE ALEXANDER CREEK 0 ('1) r (RM 10) -· rT'l .. w ....... I ....... ABOVE YENTNA RIVER 0 (RM 29) tn3: C('l) VlPJ ...... :;::) ('1- ABOVE LITTLE WILLOW CREEK . 0 :;::)0.. PJPJ {RM 50) ...... ::C.--' -'•'< < I ('1)3 ..... -sPJ ABOVE KASHWITNA RIVER ...... ~:::5 (RM 61) OVl ""SM- ('1) ::t::o3 c tO Vl ABOVE MONT ANA CREEK c c 1-Vl""S (RM 78) ("'!-~ en PJ ~ """' N("') U"'('l) m =E ....... PJ SUNSHINE (PARKS BRIDGE) 1.0 ('1-(RM 84) ooro 1-'""S ('1- ('1) 3 TALKEETNA BASE CAMP 0 -c 1-('1) (RM 103) --s PJ 0 ('1- c ;;: -s g, ('1) ri -c ABOVE 4th OF JULY CREEK 0 -s {RM 131) 0 ~ ...... ('1) (!) ~ ABOVE GOLD CREEK !-·; 0 0 {RM 137) ~ -s (!) .. ('1-0 ::1" ('1) ::l ABOVE INDIAN RIVER 1-~ 0 (RM 139) IQ c ~ II:> .0'1 ·-ABOVE PORT AGE CREEK 1-g; 0· (RM 149) -- 9L-E-3 - -TEMPERATURE (°C) ... -01 c::> en ..., ..... I • tO c. -s I ro ABOVE ALEXANDER CREEK rT1 (RM 10) . w . ..... N ABOVE YENTNA RIVER "" ~ (RM 29) Vl~ c.ro VlQJ -'•:::l rl- :::l c.. ABOVE LITTLE WILLOW CREEK "" ® QJQJ {RM 50) -'• :::c __, -'•'< < -rt>3 -sCJ ..... .. 0 (.ll:::l ABOVE KASHWITNA RIVER rt>Vl {RM 61) "0 rt' c-t-rt> ~3 <:7 Vl i't) c. ABOVE MONT ANA CREEK "" 0 > > ..... [AM. 78) COCJ ~ ["') (I) QJI't) ::j :::l m o..:::: QJ SUNSHINE: (PARKS BRIDGE) "" ..... rl- CAM 84) 1-'(l) -~ -s ..... rt' 1.0 ro C03 ..... "0 TALKEETNA BASE CAMP ~-~ 0 C'D --s (RM 103) 3:3: QJ c-t' Q)Ql I:: s·s· .... > mm C'D r 33 -"0 ABOVE 4th OF JULY CREEK -1-1 0 > CRM T31) CllC!l o· 33 """ '0'0 ...... CllCD ... ... C'D ~,;:. i::C -ABOVE GOLD CREEK .... ;; 0 ..... {RM 137) • fPfP 0 > 00 :I :I rl-CI)C/l ::s-(!)Cil -ro '0'0 ABOVE INDIAN RIVER 1-iDiii 0 CAM 139) 33 C"C' (!)Cil ..... -.ao f"~~ -_co ABOVE PORTAGE CREEK p. coao 0 (RM 149) ao- ~ LL-£-3 .,,,, TEMPERATURE (°C) -... 0 (1! 0 !" "Tl . . . -...... c.o s:::: -s ABOVE ALEXANDER CREEK ~ ('1) (RM 10) rr1 . w ...... w r ABOVE YENTNA RIVER (AM 29) i-0 Vl ::s:: S::::('l) V)QJ ...... ~ c-t-ABOVE LITTLE WILLOW CREEK 0 ~c.. • Q.>CJ (RM 50) ;;o ...... -'•'< < ('1)3 -sc.o ...... ABOVE KASHWITNA RIVER .. 0 -h::::l 0(1') (RM 61) -se-t- ('1) Vl3 ~ ('1) "'C (f) c-t-S:::: ABOVE MONT ANA CREEK -0 ('1) -s (RM 78) 3-h c-g., en ron ~ --sro m N~ o::>CJ SUNSHINE (PARKS BRIDGE) . ~ c-t-(RM 84) ('1) 1-'""'S -1.0 o::> c-t- 1-'('1) . 3 "'C TALKEETNA BASE CAMP . 0 ('1) (RM 103) 0 -s CJ ::::: c-t-"' s:::: 3" -s '(/> ('1) CD' ABOVE FOURTH OF JULY CREEK ~ .0 3 "'C (AM 131) -t' -s Cl) 0 3 -h '0 ...... !1; "' ('1) E" ABOVE GOLD CREEK ~0 .. -h Cl) 0 (RM 137) "' -s 0 ::1 c-t-C/l ;;;:r Cl) ('1) ·'0 -ABOVE INDIAN RIVER . .. 0 CD' 3 (AM 139) cr Cl) .. ~ po ... ABOVE PORT AGE CREEK 0 co ex> (AM 149) """ SLOUGH 21 SUSITNA RIVER ABOVE PORT AGE CREEK (RM 142) (RM 149) 18.8 3\-SEP 6 -,... AUG ,... AUG 31-SEP 6 u Sl.e u v v 1!1. a.. 7.8 ~ 18.8 ,.., l: w e.8 w 8.8 1-1- S.lil 8.8 I I I I I I I I I I I I I I I I I ,_, 121<488 , .. reae 121<488 1888 1888 2288 8.8 SEP 7-f3 12. SEP 7-13 -,... 8.8 ,... u u v v 7.8 a.. ••• a.. l: :E -w S.lil w 1-1- -4.8 I I I I· I I I I I I Q.488 1888 1688 2288 uaea 1688 2288 fll!llW!' 9.8 SEP 14-20 11 .a SEP 14-20 " S.lil ,... 18.8 ~ u u v 7.8 v 8.8 a.. e.8 a.. 8.8 :E l: f.LI 5.8 w 7.8 ~ 1-1- 4.8 I I I I I I I e.8 I I I t I I I Q.488 llil88 18811 2288 (Hiillil 1888 !888 2298 ~1· 8.8 SEP 21-27 SEP 21-27 '"' 7.8 " 7.lil u u v v """ 1!1.8 e.8 a.. s.8 a.. s.a l: l: w 4.8 w t.a 1-!--3.B 3.B I I I I I I I I I B"'QIII 1888 1888 22B8 8-188 l&ea re• 2288 TIME TIME ~ Figure E.3.14. Comparison of weekly diel surface water temperature variations in Slough 21 and the mains tern Susitna River at Portage Creek (adapted from ADF&G 1981c). E-3-113 ~· _, - ~ ~ ~ r- - MONT ANA CREEK SUSITNA RIVER AT PARKS HIGHWAY BRIDGE (RM 76) CRM 84] 15 . .11 15-21 17 • .11 .JUN 15-21 JUN "' 1-t.lil " 11!1.8 u u v v 13.111 15.8 a.. 12.111 a.. 14.8 ::t: ::t: l.LJ 11 .a l.LJ 13.8 1-1- 18 . .11 12.8 I I l I I I 1888 1158111 2288 .... ·-18811 15.8 22-28 te.a ..I UN 22-28 JUN "' 14.8 "' IS.a u u v 13.8 v 14.8 a.. 12.8 a.. 13.1l ::t: :L l.LJ u .a l..LJ 12.8 1-r- 18.8 11.8 I l I I l 1888 1888 2288 1888 15811 13.8 JUN 29-..JUL 5 13.8 ..I UN 29-.JUL 5 "' 12.a ,., 12.8 u u v v II .Ill II .a a.. ta.a a.. 18.8 ::t: :L l.LJ 9.8 w 9.8 r-1- s.a 1!1.8 -I I I I I I I I I I 188lil 1 eaa 2288 a-tea 188111 teaa H.a JUL 6-12 14.8 .JUL 6-12 G 13.a "' 13.8 u v 12.8 v 12.8 a.. 11 .8 0. 11 . .a :L :L LLJ 18.a l.LJ 18.8 1-1- a.a e. I I I I I I I j I I 1114Btil laaG 18Btil 2288 111488 tasaa 181i18 TIME TIME Figure E.3.15. Comparision of weekly diel surface water temperature variations in Montana Creek and the mainstem Susitna River at the Parks Highway Bridge (adapted from ADF&G 1981c). I I I 22M I I I 2288· I 22811 I I 2288 average of two hour intervals for a 24 hour period (i.e. each point equals the average water temperature at a specific time of day for a seven day period). The values on each temperature axis were selected to best reflect the range of water temperatures recorded. Each temperature axis encompasses a 5°C span in water temperature. Diel temperature fluctuations can differ in a slough from those recorded in the mainstem (Figure E.3.14). Surface water temperatures in Slough 21 during September 1981 significantly increased during the afternoon, while the mainstem Susitna River temperature near Portage exhibited no corresponding increase, and in some cases decreased slightly (these sites are separated by 6 river miles). Slough temperature increases may be due to the increased solar warming of the shallow water in the sloughs; the glacial source of mainstem flows keeps water temperatures nearly constant. These data were collected during a period when the slough head was dewatered; thus mainstem water had little influence on slough temperatures. Slough water temperatures would be expected to correspond more closely to mainstem temperatures during periods of high discharge when mainstem flows enter the slough. Figure E.3.15 illustrates temperature regimes for Montana Creek and the mainstem Susitna River at the Parks Highway Bridge for mid-June through mid-July 1981. The timing of diel temperature fluctuations in Montana Creek is similar to that in the mainstem; however, mainstem fluctuations are dampened. It appears that the larger amount of water in the Susitna buffers temperature change. Diel temperature patterns may exert an influence fishery resources and the productivity of aquatic habitats (Hocutt et al. 1980; \-lard and Stanford 1979; E-3-20 - ~I - - - - - - - Baxter and Glaude 1980). Depending upon the relationship between surface and intragravel water temperatures, alteration of diel variations may influence egg deve 1 opment and fry emergence (Reiser and Bj ornn 1979). Altering Sus itna River temperatures may affect stocks of rearing fish in unknown ways. The effects on productivity in the Susitna River are also unknown. Diel temperature fluctuations may influence or be related to diel fluctuations in productivity. However, because primary productivity was not evaluated during the 1981 field season, it is unknown whether diel fluctuations occur in pro- ductivity. Studies should be considered to define the relationship between surface and intragravel water temperature fluctuations, as well as temperature influence on productivity in the mainstem, sloughs, and major tributaries. 3.5 Selected Slough Habitat Studies* 3.5.1 Introduction Comprehensive water quality and discharge data were collected on a cooperative basis with the USGS at five selected slough habitat study sites between Talkeetna and Devil Canyon (Sloughs 8A, 9, 168, 19, and 21, Figure E.2.20). Figure E.3.16 illustrates stream gradient and relative elevation of each slough between Talkeetna and Portage Creek. Planimetric and morphometric maps of Sloughs 16B, 19, and 21 are included in the AH subject. report (ADF&G 1981c). Planimetric maps of Sloughs 8A and 9 are presented in this report (Figures E.3.17 and E.3.18). These sites were selected because they represented varied types of slough habitat and fishery activities as deter- * Refer to Sections 2.6, 2.7 and the AH subject report (ADF&G 1981c) for additional site description and background information. E-3-21 ..... ...J w 900 > LLJ ..J <C 800 w (./l z <C 700 w :1E LLJ > 0 600 CD < 1-w 500 w lJ... -z 0 400 t= <C > LLJ 300 ...J LLJ 200 80 90 100 110 120 130 140 150 160 RIVER MILE Figure E.3.16. Susitna River gradient between Talkeetna and Portage Creek showing positions of selected habitat study sloughs (adapted from R&M 1982b). E-3-22 - - .... ~ - - ~ - - fT1 I w I N w J -----i!l ~ ••. :' ·: .. ~.· •• •••• • ......... • • ~ ··: • ...... ; ... :·~· •••• :·i:-.-·:.t ." .. -:: ....... : .. · ... :· .... , ........... • .. • :·· ........... ~ ... -T .... · ~ ~·· ··~ ... :-.: ... :.·:;·· ...... . Susitno . River 7 ~ ........ ;.::~--.. .:·-~···::·-~·· .. ···;··,·:: .. . ··=··'· : .. ::.;.::i:--~:·.·.: ., ... 1'".-,,·,·:. :-·.:·.:,...;:-.......... ~,.:,-••. : .... · .• I -- Figure E.3.17. Planimetric map of Slough 8A. SLOUGH 8A & = ADF&G Temporary Bench Mark 0 ~ R&M Temporary Bench Mark LAX =Lower River Cross Section (below Devil Canyon) -------= A&M Transect -----= ADF&G Transect ADF&G Survey Date: Oct. 10-11, 1981 rrl I w I N .j::oo 5 R&M LAX 31 4 -AIIIIf------Susima River Figure E.3.~8. Planimetric map of Slough 9. ) SLOUGH 9 & = AOF&G Temporary Bench Mark LAX = Lower River Cross Section (below Devil Canyon) = R&M Transect = ADF&G Transect ADF&G Survey Date: Oct. 14, 1981 .! - - - - - - - - mined from: a) fishery, water quantity and quality baseline data collected by the ADF&G (1974, 1977, 1978); and b) a reconnaissance trip to the study area in June 1981 by ADF&G Su-Hydro and USGS personnel . Supplemental fishery and physiochemical data for these sloughs are presented in Chapter Two. Water quality data analysis is preliminary and interpretation is limited to three sets of data collected in the summer of 1981. 3.5.2 Relationships Between Water Quality in the Mainstem River and Selected Sloughs with Respect to Mainstem Discharge Mainstem and slough water quality data can be used to identify relationships between these two systems. At high mainstem Susitna River flows, many of the sloughs are essentially shallow branches of the mainstem. As mainstem discharge drops, the flow of mainstem water into the sloughs is reduced until mainstem surface water no longer enters the headwaters of the sloughs.* Turbidity is one of the water quality parameters that can be used for observing these discharge water quality relationships. Turbidity levels in sloughs drop below mainstem levels when slough headwaters are no longer interconnected with mainstem surface waters (Table E.5.8 in ADF&G 1981c). This however does not preclude the possibility that mainstem flows enter slough channels as intragravel seepage.* * See Sections E.2.7 and E.3.2 for additional slough/mainstem relation- ships. E-3-25 E-3.;.26 s... Q) ..0 0 +-' u 0 Vl 4-u_ 0 N 0) 1'-- Q) CTl s... 1'0 ..!:: u Ill •r- ""0 s... Q) > •r- Ill ::s V1 E Q) +-' Ill s:: •r- ..!:: CTl ::s 0 .-- (/) 4- 0 ..!:: +-' ::s 0 ::E Q) +-' 1'0 r- 0.. - - - - During periods when the surface water in the sloughs is c1ear there can remain some influence of mainstem turbidity at the mouth if a backwater area exists. Another parameter which demonstrates mainstem/slough relationships is the concentration of suspended trace metals. When mainstem discharge is high and enters the sloughs, trace metal concentrations in the sloughs are high (Table E.5.8 in ADF&G 1981c). At high mainstem flows in Sloughs 8A, 9, and 21, slough trace metal concentrations essentially equal those measured in the mainstem (Table £.5.8, ADF&G 1981c). At high mainstem flows, trace metal levels in Sloughs 168 and 19 were somewhat lower than those measured in other study sloughs and the mainstem river. This relationship may indicate that a larger percentage of flow in Sloughs 168 and 19 originates from groundwater or other sources. In spite of this, a positive correlation is still evident between mainstem flows and trace metal concentrations in these sloughs when slough inlets receive mainstem surface flows of the Susitna River. At low mainstem discharges, trace metal concentrations in all sloughs are well below concentrations in the mainstem. Trace metals are associated with suspended sediment rather than with dissolved constituents (Table E.5.8 in ADF&G 1981c). Thus, as slough turbidity drops, sediment-associated parameters such as trace metal concentrations also drop. Other water quality parameters in the sloughs during low mainstem flows do not vary significantly from those of the mainstem. * See Sections E.2.7, E.3.2 and Chapter 4 for additional slough/mainstem relationships. E-3-27 !Jli w I N 00 Plate 8. View of head of Slough 168 (mainstem Susitna River discharge 14,500 cfs), September 9, 1981. - - 3.5.3 Relationships Between Water Quality Characteristics in Study Sloughs A brief overview of water quality data presented in the AH subject report (ADF&G 1981c) for each of the five selected habitat study sloughs (Sloughs 8A, 9, 16B, 19, and 21) reveals intrinsic differences between water quality in each of the sloughs. Water quality differences may be explained by dif- ferences in morphology. For example, the turbidity in Slough 19, during high mainstem discharge, is low compared to the other four sloughs. This can be attributed to the source of water in Slough 19; it is the only slough that is not connected to the mainstem at its head and is almost entirely spring fed. The lower slough turbidity is likely the result of the lack of mainstem water influence (See section 3.2 and Figure E.3.2). Although water quality in Slough 19 appears to be independent of direct mainstem influence, stage within this slough, is directly affected by the mainstem Susitna at high flows. During high mainstem flows the stage of the mainstem Susitna River acts as a hydraulic barrier at the slough outlet and a large backwater forms in the lower end of the slough (See chapter 4). Under these conditions, discharge data indicate that outflow from the slough is essentially eliminated (Table E.5.8 in ADF&G 1981c). Eventually, the stage in the mainstem Susitna drops enough to allow slough outflow. This and similar backwater areas in other sloughs provide rearing areas for juvenile fish. E-3-29 ..., I w I w 0 Plate 9. View of mouth of Slough 168 (mainstem Susitna River discharge 14,500 cfs), September 9, 1981. - - Water quality characteristics of Slough 168 also differ from those of other sloughs. The specific conductance and alkalinity are markedly lower in Slough 168 than in any of the other sloughs studied (Table E.5.8 in ADF&G 1981c). Slough 168 also has the lowest turbidity (with the exception of Slough 19) and the lm·Jest trace metal concentrations during both high and low mainstem flows, of any other sloughs or the mainstem Susitna. It is suspected that this occurs because the Indian River (approximately 1 mile upstream of Slough 168) contributes a portion of the surface and subsurface flows in the slough. Sloughs 8A, 9, and 21 all appear to behave similarly. During periods of high discharge in the Susitna River, the water quality in each of these sloughs is essentially the same as that in the mainstem. As discharge drops, a critical mainstem discharge level is attained at which point the clearwater sources in each slough becomes predominant. A backwater area forms at the mouths of these sloughs during periods of high mainstem discharge. Data for Slough 21 (presented in the AH subject report, ADF&G 198lc) indicate that surface water diel temperatures ranged from 4.5 to 8.5°C while the intragravel temperature remained constant at 3.0°C from August 27 to September 29, 1981. This temperature relationship is important to the fishery because both larval devel~pment and emergence from the egg is dependent upon water temperature in the substrate {Reiser and Bjornn 1979). Subsequent fry growth and behavior would be dependent upon surface water temperatures (Reiser and Bjornn 1979). Because of the relative importance of slough habitats to the fishery resources of the Susitna River, it will be important to further define relationships E-3-31 Plate 10. Aerial view of Slough 19 (mainstem Susitna River discharge 7,440 cfs), October 15, 1981. between mainstem discharges and slough water quality characteristics. Further studies should be directed towards: 1) determining the actual sources and volumes of base flows in the -sloughs; - - 2) studying a greater variety of sloughs with different characteristics; 3) determining surface and intragravel water temperatures in the sloughs and the factors which influence them; 4) determining concentrations of intragravel oxygen in the sloughs and the factors which influence them; and 4) evaluating data collected by the ADF&G and other investigators during and prior to 1981. E-3-33 ,... \ .... i - ,... i \ 4. PfflJICTIV£ JVDliLS - 4.0 PREDICTIVE MODELS 4.1 Introduction This chapter discusses some of the preliminary computer models which have been developed by Acres and their subcontractors to predict post-project temperature and stage/discharge relationships in the Susitna River downstream from the proposed two dam hydroelectric system. Included in this chapter are comparisons between predicted and known (see ADF&G 1981c) stage, discharge and temperature characteristics. Existing data can be used to refine the current models and identify additional data collection requirements. 4.2 Stage Analysis R&M Consultants, Inc., subcontractors to Acres American, Inc., applied the HEC-2 hydraulic model (R&M 1982a, b) to forecast water surface elevations (WSEL) in the Susitna River between Talkeetna and Devil Canyon at various discharges. This model is likely to become a key decision making tool as feasibility studies progress (e.g. what WSEL at specific sites, such as sloughs, are associated with certain mainstem Susitna streamflows). Therefore, it is important to establish confidence in the predictive capabilities of the model. The HEC-2 hydraulic model has been used to predict WSEL at approximately 70 mainstem cross sections for a range of mainstem discharges. Predicted stage/discharge relationships can be compared with observed WSEL or stage data E-4-1 collected by the AOF&G at eight mainstem sites between Talkeetna (R.M. 97.0) and Devil Canyon (R.M. 152.0) during the 1981 summer field season (Table E.4.1). Elevations at two of these sites, Sloughs 168 and 19, have been referenced to the project (MSL) datum, thereby allowing WSEL datum to be computed from their respective stage data. For each site, an observed gage height or stage/ .discharge relationship was plotted using 1981 Susitna River discharge data from the Gold Creek station (USGS 1981; Figures E.4.1 -E.4.8). The observed stage/discharge rel ati onshi ps were compared to WSEL/di scharge relationships predicted by the HEC-2 hydraulic model. Either the closest WSEL datum for an R&M survey cross section (if within 0.1 mile of the mainstem AOF&G site) or WSEL datum interpolated from the nearest upstream and downstream cross sections (assuming a 1 inear drop in elevation between the cross sections) were used for comparative purposes. When comparing predicted WSEL/discharge relationships to observed gage height or stage/discharge rel ati onshi ps, the characteristic to note is the relative slope of each plot (Figures E.4.1-E.4.8). Several discrepancies between predicted and observed values are apparent. The model generally predicts a smaller than observed change in mainstem stage (or WSEL) when the discharge values are below 20,000 cfs. Therefore, more of the river channel would become dewatered for an incremental decrease in streamflow than the model predicts. An exception is noted in the vicinity of Slough 19 where the observed rate of changes in stage of the Susitna River, for discharge values less than 20,000 cfs, is smaller than that predicted by the model. The model also predicts that WSEL values at Sloughs 16B and 19 (for a given rnainstem Susitna River streamflow) will be higher than actually observed at these sites E-4-2 - - - - - - - - - ;~ - Table E.4.L Comparison of observ-ed stage (ADF&G 1981c) to predicted water surface elevation (WSEL) data (R&M 1982a, b) at various Susitna River discharges, cfs (USGS 1981), used in developing Figures E.4.1-£.4,8. OBSERVED PREDICTED Location Stage Discharoe* WSEL Discharse* Ta 1 keetna AA Fish Camp 362.7 9,990 (R.M. 101.0) 1.86 14,100 363.4 13,800 2.36 16,600 363.8 17,508 3.64 24,200 364.5 24' 107 5.18 35,900 365.3 35,540 7.14 51,900 366.8 53,566 Mainstem 2 1.46 10,600 468.4 9,990 (R.M. 114.4) 2.64 -14 ,600 469.5 13,800 3.07 17 ,400 470.3 17,508 4.36 28,800 471.9 24,107 5.82 38,400 473.5 35,540 6.16 43,000 476.4 53,566 Curry AA Fish Camp 0.00 10,500 516.6 9,990 (R.M. 120.0) 1. 52 13,900 517.1 13,800 2.16 17,200 517.5 17,508 3.63 24,000 518.4 24,107 5.16 36,300 519.3 35,540 6.07 58,200 521.2 53,566 ~iainstem Susitna-Curry 521.8 9,700 (R.M. 120.7) 522.6 13,400 2.33 17,200 523.3 17,000 3.86 24,900 524.3 23,401 5.23 34,200 . 525.4 34,500 5.68 36 '100 527.2 51,998 Mainstem Susitna ~ 1.18 9560 684.0 9,700 Inside Bend 2.22 14,600 685.1 13,400 ( R.M. 136.9) 2.51 16,200 685.8 17,000 2.88 18,800 687.0 23,401 688.1 34,500 689.9 51,998 Slouoh 168** 695.10 8,890 699.5 9,700 {R.~( 138.0) 695.80 10,400 700.4 13,400 696.00 10,800 701.1 17,000 696.10 11,300 702.0 23,401 696.50 11,800 702.9 34,500 697.00 14,500 704.4 51,998 697.40 15,900 ---Data unavailable. * Susitna River at Gold Creek. ** Stage as converted into project datum elevation~ E-4-3 Table E.4.1. (Continued). . - OBSERVED PREDICTED Location Stage Discharge* WSEL Discharge* Slough 19** 720.00 8,890 722.1 9,540 (R.M. 140.0) 720.30 9,560 723.0 13,178 720.30 10,100 723.7 16,720 ~ 720.40 10,400 724.8 23,001 720.40 10,800 725.8 33,910 720.60 11,800 727.4 51,109 -721.20 15,700 I 722.80 16,000 Mainstem Susitna -Island 1.41 28,600 810.9 9,540 - ( R • ~1. 146 . 9 ) 2.39 33,400 812.0 13,179 3.23 38,400 812.8 16,720 3.66 43,000 814.2 23,001 -· 4.21 46,400 815.9 33,910 4.51 51,300 819.1 51,109 -' ---Data unavailable. * Susitna River at Gold Creek. ** Stage as converted into project datum elevation. - - - E-4-4 -..... -I 370 en :: L6l > -0 -I ID w < 0 0 1-:: w w t\1 -1.1. 365 z 0 w 0 J: j:: w < J: > 1-w -I 0 w z La c;; 0 ::1 j WSEL Predictions I < (g u.. a: C) ::1 0 en 0 a: ~ w 1-< a: 3= 1- 0 < w "'~ 1- 0 0 361 w a: ~\l ~\l ~\l ll. ,r;::.~ <::I ~~ <;)• ~ ,r;:; Discharge (CFS) at Gold Creek (USGS 15292000) 10.0 ll. :: < 0 -I w w J: 3= 5.0 J: en """ u: < ..... z ~ 1-w 0 w ,... -::.:: -I ~ < 1-a: 1-< I Stage Data ..... 1-w w LJ.. ...... w 0 < 1-en 1.0 'i::J\l 'i::J\l >.::,0 C) C) C) c· <;:::,• <;:::,• ' ~ ,>.::. Discharge (CFS) at Gold Creek (USGS 15292000) Figure E.4.1. Comparison of the observed stage/discharge relationship (ADF&G 198lc) to the predicted .... WSEL/discharge relationship (R&M 1982a, b) for the Susitna River at Talkeetna Base Camp ( R. M. 101.0). """' E-4-5 480 475 WSEL. Predictions I Discharge (C~) at Gold Creek (USGS 15292000) 10.0 ~ ~ ::E 5,0 ri. .... ~ :;: w r-en z < ::s r-< r- I Stage Data w w ~ ...... w 0 < r- {/) 1.0 ~~ .._<:::J• <;:,<:;) <;:,<:;) r;;:,? c? ~ .._c::i Discharge (CFS) at Gold Creek (USGS 15292000) Figure E.4.2. Comparison of the observed stage/discharge relationship (ADF&G 1981c) to the predicted WSEL/discharge relationship (R&M 1982a, b) for the Susitna River at the Mainstem 2 habitat location (R.M. 114.4). E-4-6 - - - .... - - - - - - - """' - ,."!~ - ..J (/) :iE IJ.l > 0 c:l <C 1-w w u.. z Q ;-< > w ..J w w (.J <C u.. a: ::::l (/) >a: I.U 1-< ~ c IJ.l 1- 0 ·@ a: a.. 1-w w u.. ..J w c 0 :iE N ' (.) w J: w J: 1- 0 ~ (/) ::::l ~ <q 0 C\1 ::; a: 1- <C 530 525 10.0 5.0 j WSEL Predictions I r::P ~ r;:;,~· .... Discharge {CFS) at Gold Creek (USGS ·1 5292000) I. Stage Data Discharge (CFSJ at Gold Creek (USGS 15292000) Figure E.4.3. Comparison of the observed stage/discharge relationship (ADF&G 1981c) to the predicted WSEL/discharge relationship (R&M 1982a, b) for the Susitna River at the Curry Fish'wheel Camp (R.M. 120.7). E-4-7 z 0 Q w 1-:t: <C w ::> :t: WI- -' w a w ~ 0 >!) <C :;, u.. (g a: (g :;, ci Cl) C\1 a: ~ ~ <C a: :: 1- 0 <C w 1-g 0 w if > a: 5 0 1-w w u.. w a <C 1- C/) 530 525 10.0 5.0 Figure E.4.4. WSEL Predictions ~~ f:l9 .._C) Discharge (CFS} at Gold Creek (USGS 15292000} I Stage Data s:;,O . s:;,'? .._<;;J Discharge (CFS) at Gold Creek (USGS 15292000) Comparison of the observed stage/discharge relationship (ADF&G 198lc) to the predicted WSEL/discharge relationship (R&M 1982a, b) for the Susitna River at the Curry habitat location (R.M. 120.7). E-4-8 - - - - - -· - - - - - - - - ....1 r:n ::l; UJ > 0 .:.J co w· <C 0 690 1-0 ~ ~ 685 '-" I 0 :z ~ UJ 0 ii5 ~ 1- UJ UJ u.. UJ 0 <C 1-r:n 10.0 5.0 F i gu re E. 4 . 5 . ]. WSEL Predictions ] '>:;~ '::l ..... ~~· Discharge {CFS)at Gold Creek {USGS 15292000) Stage Data '>:;~ '>:;~ ... c::; Discharge (CFS) at Gold Creek (USGS 15292000) Comparison of the observed stage/discharge relationship (ADF&G 198lc) to the predicted WSEL/discharge relationship (R&M 1982a, b) for the Susitna River at the Mainstem Susitna-Inside Bend habitat location (R.M. 136.9). E-4-9 1- <( ,.... ...J en ·:!; 1.1.1 > 0 a::l <( 1-w 1.1.1 u.. ..... z 0 i= <( > 1.1.1 ...J w w 0 <( u. a: :::l CJJ a: ~ <( 3: 710 PREDICTED WSEL ,.... 0 705 a:i C") ~ a: ..... en (0 z OBSERVED WSEL " :::l 0 ...J UJ 701 ~'>:) r::;'>::J 'Q~ '>:)~ '\ Discharge (CFS) at Gold Creek (USGS 15292000) Figure E.4.6. Comparison of the observed stage/discharge relationship (ADF&G 1981c} to the predicted WSEL/discharge relationship (R&M 1982a, b) for the Susitna River at Slough 168 ( R • M • 138 . 0 } . E-4-10 - - - - - - - - - I"" 1- <( ,... ..I (/) :::· w ,... > 0 q co 0 ,... <( ':t 1-w ~ w L.i. a: ._ ""~ ._ z 0) 0 i= J: <( > 0 w ;:) ..I 0 w ..I w (/) 0 <( u. ,.,., c: :::! (/) c: w 1--<( !i: 1"""' - - 730 725 _, .-OBSERVED WSEl 721 r::Jt::) r::Jt::) r::Jc "'~ c~ !;:) " -.,c· Discharge (CFS) at Gold Creek (USGS 15292000] Figure E.4.7. Comparison of the observed stage/discharge rel ati onshi p (ADF&G 198lc) to the predicted WSEL!discharge relationship (R&t·1 1982a, b) for the Susitna River at Slough 19 (R.M. 140.0). E-4-11 r::Jc r::J~ .... !;:) -1 00 820 ::! w > 0 OJ <( -1 1-w w a w 0 c.. ::! C\1 815 z ' 0 0 i= w <( :I: > w w -1 :I: w 1- w 0 0 z <( in c.. ::J o; 0) ::l 00 cd I WSEL. Predictlona j ... a: w :i 1- <( a: == 0 1- <( w 1- 0 0 w a: a.. co §J? >.; Oiacharge {CFS) at Gold Creek (USGS 15292000) 10.0 0 z <( -1 5!2 <( 5.0 z 1- (ij ::J ...... 00 ::! C) w cd 1-... 00 ;?; :i <( ::! a: 1-'-' <( Stage Data ...... 1-w w c.. w <:l <( 1- 00 1.0 cr::. c? ' >:P r::P c? c? '-j ,<:::i Discharge CCFS) at Gold Creek (USGS 15292000) Figure E.4.8. Comparison of the observed stage/discharge relationship (ADF&G 198lc) to the predicted WSEL/discharge (R&M 1982a, b) for the Susitna River at the Mainstem Susitna-Island habitat location (R.M. 146.9). E-4-12 - - - - - - - - - - - - - - (Figures E.4.6 and E.4.7). This discrepancy indicates that larger Susitna River streamflow values, than are predicted by the model, will be required to provide a specific stage at these locations. It should be pointed out that observed discrepancies may be partly attributable to the assumption used when interpolating specific WSEL datum at various discharges for a given site, that is, elevation will drop linearly between cross sections. It is also important to note that observations indicate that stage at each site reacts in a unique fashion to changes in mainstem Susitna River discharge. The implications of these comparisons are significant, suggesting that it is difficult to predict reliable WSEL for various discharges at mainstem study sites with the existing data base. Accordingly, additional cross sections are required to calibrate the model or a different approach is needed to predict accurate WSEL values for specific mainstem discharges at particular locations. 4.3 Water Temperature Analysis Acres has applied a model to predict pre-project and post-project mean monthly surface water temperatures for the Susitna River reach between Talkeetna and De vi 1 Canyon (Acres 1982). Predicted (Acres 1982) pre-project temperature data* for June through September, are compared to the 1981 observed (ADF&G 1981c) mean monthly water temperatures for the same period for nearby sites (Table E.4.2). Differences between observed and predicted temperatures * Calibrated with 1981 climatic and Susitna River discharge data for the open-water season (Trihey 1982). E-4-13 * (/) )::> c.. 3:: -1 (1) c: c: 0 PJ ,_... -o tO ......... :::s r:::r :::s <+ c: '< <+ n (1) Vl :::y CD 0 3 <+ 3 r:::r fTI -o (1) . ...... -s """ (1) . c+ N ro . c. PJ ....... Temperature prediction for LRX 34 <+ on c+ 0'1 co 0 (1) ("'") 0 PJ . . R.M. 130.5 3 3 ~ ""'-~ 1-' -o ..-...-o Ul 11) )::> PJ ro -s Cl -s c+ PJ ..., ....... co Observed temperature value for <+ 12'> Vl ..-... 0'1 t.D c (j} 0 ~ . . R. ~1. 131.3 -s :::s ........ """ 0'1 N ltll-' N Vl t.D 0 CO-t, 3 ......... ~ 0 ;:c.no :::s n ..._, 0"' c+ -s .. Ul ~ Temperature prediction for LRX 47 (1) CD 1-' Ul ("i--s -o 0'1 co 0 R.M. 137.2 0 < CD . . . 1-' (1) -s ....... " 0 t.D-o a. fTl ..... co-s I 0 N(l)3 """ 0.. ...__. 0. CD I Observed temperature value for .....JeQ.I ....... 0 U1 co t.D -t,O:::S """ ....., . . R.M • 136.8 oc+ ~ U1 0'1 -sro3 -s * 0.0 (1) c+ :::s n ::r3c+ 0 CDCD:::Y -s PJ ........ c. Ul::::l'<: Temperature prediction for LRX 54 c: Vl3Vl U1 co t.D R.M. 140.8 ..... o c . . . c+::::l-s t.D U1 t.D :::Sc+-t, PJ :::y OJ __. n A:J'<: CD " U1 t.D Observed temperature value for ..... . . . <Vl:( """ 0'1 1-' R.M. 138.7 (l)C:PJ * -s-srt . -I, CD OJ-s n rnrt (1) :t:3 co Temperature prediction for LRX 61 PJ""' U1 t.D c+CD . . . R.M . 148.7 CD-s ""'-~ U1 co -sPJ ("i-c: -s (1) ....... Observed temperature value for Vl 0'1 co 0 .. . . . R.M . 148.8 0 ""'-~ 0 * J - - - - are minimal, suggesting that the model can be used to predict temperatures for the open-water season when calibrated. However, these temperatures only represent a portion of the 1981 open water season conditions for the mainstem Susitna River and do not include temperatures for the ice covered season. Therefore, year-round temperature data must also be collected to assess how well the Acres temperature model can predict accurate year-round mainstem surface water temperatures. Temperature predictions are particularly important, because temperature significantly affects the suitability of the mainstem Susitna River, its associated sloughs, and side channel habitats to support various life phases of fish species. Chum salmon, for example, could be highly impacted by altered thermal regimes (Reiser and Bjornn 1979) because they use all three habitats seasonally (ADF&G 1981a, d). As a result, the applicability of the Acres temperature model to slough and side channel habitats should also be studied. 4.4 Pre-project and Post-project Flow Comparisons R&M Consultants calculated theoretical post-project monthly discharges for the Susitna River at Gold Creek (Table E.4.3), Sunshine, and Susitna Station based on the assumption that the proposed two dam system had gone into operation in 1950 (R&M 1982a). Historical discharge records (USGS 1977, 1978a, 1978b, 1979) for the Susitna River at Gold Creek (Table E.4.4), Sunshine, and Susitna Station, were used to predict the outflow regimes {post-project discharges) from the dams that would have provided optimum power production (Case A scenario). E-4-15 rr1 I .p. I --' 0) Table E.4.3. Case A scenario mean monthly post-project discharge (cfs) for the Susitna River at Gold Creek (R&M 1982a) for the years 1950-1978. YEAR OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG 1950 7736 9073 12669 10814 8961 7877 7931 10434 10176 8338 5773 1951 6967 7875 9414 8340 6614 6604 6355 10016 9362 7650 6111 1952 7464 10635 13130 11386 9173 8031 7856 8838 13752 9211 8027 1953 10094 11388 12930 10886 8992 7971 8195 11809 12915 7642 9453 1954 7476 9991 12729 11087 9173 7932 8031 13161 12866 8060 9628 1955 7006 10074 13274 11581 9573 8251 7998 10179 12109 8858 14554 1956 6843 9791 12529 10766 9143 8092 7972 12287 13255 15641 16005 1957 7698 10941 13371 11487 9673 8352 7993 11151 11989 8472 10243 1958 10104 11845 14487 11759 9480 8299. 8114 10518 10704 7992 9257 1959. 6972 7686 10229 11234 9480 8131 8103 13428 12095 9401 14602 1960 8451 10741 13430 11632 9625 8348 7967 10312 9259 8359 6411 1961 9686 10891 13923 12239 9926 8961 9231 11297 13741 10718 12031 1962 7700 10591 13329 11687 9673 8552 8281 8832 16353 14623 16462 1963 8616 10691 13229 11387 9673 8152 7793 11310 12406 15775 14713 1964 8341 10141 12723 10835 9139 7974 7878 8373 16524 14787 8482 1965 7082 9062 12440 10747 9033 8051 7941 9600 11602 9908 10868 1966 9097 9989 12861 11186 9473 8452 8356 10127 14134 8370 7412 1967 6876 7599 11735 11286 9573 8351 8056 10504 11886 12937 17240 1968 7589 10244 13284 11768 10073 9051 8491 10929 12927 13800 8329 1969 6793 7664 9304 10510 8896 7967 8091 9312 8547 6053 5164 1970 7172 8004 9519 8420 6801 6968 5875 6737 11552 9506 6034 1971 7144 7780 8987 8222 7128 7462 8403 8918 12834 8086 6732 1972 6900 7758 11879 12026 10201 8974 8291 13492 14059 14508 10628 1973 6630 9987 12694 10986 9372 8151 7851 8526 11066 6587 5581 1974 7060 7922 9300 7844 8798 7876 7859 10869 10046 7560 5682 1975 6916 7775 9304 8227 . 6515 7573 8173 11254 12710 14690 9124 1976 9631 9884 12310 10760 9123 8051 8050 11258 11496 6634 5271 1977 7194 8175 9717 8191 8160 8651 8260 11686 13729 11817 9834 1978 9231 11416 13819 11815 9841 8756 8283 8295 8865 7516 5777 .1 -J SEP 4906 12518 6692 8148 6109 8159 14617 12789 4995 9909 11258 6466 12177 8131 5156' 12339 5355 14905 5032 4957 5151 5270 5634 4932 5413 9298 5070 5861 5071 rn . I ~ I -' ...... -l l Table E.4.4. Mean monthly pre-project discharge (cfs) for the Susitna River at Gold Creek (USGS 1977, 1978a, 1978b, 1979) for the years 1950-1978. YEAR OCT NOV DEC JAN FEB MAR APR f1AY JUN JUL AUG SEP 1950 6335 2583 1439 1027 788 726 870 11510 19600 22600 19880 8301 1951 3848 1300 1100 960 820 740 1617 14090 20790 22570 19670 21240 1952 5571 2744 1900 1600 1000 880 920 5419 . 32370 26390 20920 14480 1953 8202 3497 1700 1100 820 820 1615 19270 27320 20200 20610 15270 1954 5604 2100 1500 1300 1000 780 1235 17280 25250 20360 26100 12920 1955 5370 2760 2045 1794 1400 1100 1200 9319 29860 27560 25750 14290 1956 4951 1900 1300 980 970 940 950 17660 33340 31090 24530 18330 1957 5806 3050 2142 1700 1500 1200 1200 13750 30160 23310 20540 19800 1958 8212 3954 3264 1965 1307 1148 1533 12900 25700 22880 22540 7550. 1959 4811 2150 1513 1448 1307 980 1250 15990 23320 25000 31180 16920 1960 6558 2850 2200 1845 1452 1197 1300 15780 15530 22980 23590 20510 1961 7794 3000 2694 2452 1754 1810 2650 17360 29450 24570 22100 13370 1962 5916 2700 2100 1900 1500 1400 1700 12590 43270 25850. 23550 15890 1963 6723 2800 2000 1600 1500 1000 830 19030 26000 34400 23670 12320 1964 6449 2250 1494 1048 966 713 745 4307 50580 22950 16440 9571 1965 6291 2799 1211 . 960 860 900 1360 12990 25720 27840 21120 19350 1966 7205 2098 1631 1400 1300 1300 1775 9645 32950 . 19860 21830 11750 1967 4163 1600 1500 1500 1400 1200 1167 15480 29510 26800 32620 16870 1968 4900 2353 2055 1981 1900 1900 1910 16180 31550 26420 17170 8816 1969 3822 1630 822 724 723 816 1510 11050 15500 16100 8879 5093 1970 3124 1215 866 824 768 776 1080 11380 18630 22660 19980 9121 1971 5288 3407 2290 1442 1036 950 1082 3745 32930 23950 31910 14440 1972 5847 3093 2510 2239 2028 1823 1710 21890 34430 22770 19290 12400 1973 4826 2253 1465 1200 1200 1000 1027 8235 27800 18250 20290 9074 1974 3733 1523 1034 874 777 724 992 16180 17870 18800 16220 12250 1975 3739 1700 1603 1516 1471 1400 1593 15350 32310 27720 18090 16310 1976 7739 1993 1081 974 950 900 1373 12620 24380 18940 19800 6881 1977 3874 2650 2403 1829 1618 1500 1680 12680 37970 22870 19240 12640 . 1978 7571 3525 2589 2029 1668 1605 1702 11950 19050 21020 16390 8607 Observed mean monthly pre-project discharges are compared to predicted post- project discharges for the Susitna River at Gold Creek, Sunshine and Susitna Stations over the period 1950-1978 in Table £.4.5 and plotted as hydrographs in Figures E.4~9 to £.4.11. Comparisons of observed pre-project and predicted post-project discharges with the periodicity of adult salmon passage and spawning for the Susitna River at Gold Creek are illustrated in Figures E.4.12 and E. 4.13. These figures and tables illustrate that the observed pre-project Susitna River streamflows at Gold Creek Station are altered by the proposed power production flow regimes. During winter, flow is higher due to increased power demand, while during summer, flow is reduced to refill the reservoir (Figure E.4.9). As a result, normally observed high summer discharge events (floods) are dampened or eliminated (Figures E.4.12 and E.4.13). Susitna River hydro- graphs for Sunshine Station (downstream of the Talkeetna and Chulitna Rivers) and at Susitna Station (downstream of the Yentna River) show predicted post- project flows deviating in simi 1 ar ways from observed pre-project conditions (Figures E.4.10 and E.4.11). However, differences between predicted post- project and observed pre-project conditions of the mainstem Susitna River decrease progressively downstream of the Talkeetna, Chulitna, and Yentna Rivers. Fish movement may be altered by changes in the flow regime (see Section 2.3). Fish passage into sloughs can be obstructed if these habitats are dewatered. Many sloughs between Talkeetna and Devil Canyon begin dewatering at their heads when mainstem streamflows drop to approximately 20,000 cfs (at E-4-18 .... - - - ,_ ,_ - ~ """' - - Table E.4.5. Comparison of mean monthly pre-project (USGS 1977, 1978a, 1978b, 1979) and predicted post-project power discharges, cfs (R&M 1982a), for the Susitna River at Gold Creek, Sunshine and Susitna Station over the period 1950-1978. Gal d Creek Sunshine Susitna Station Discharge* Discharge* Discharge* Pre-Post-Pre-Post-Pre-Post- Month Eroject Eroject** Eroject Eroject** eroject eroject** OCT 5,664 7,810 13,775 15,921 29,822 31,967 NOV 2,465 9,504 5,835 12,874 12 ,577 19,616 DEC 1,776 12,019 4,195 14,438 8,177 18,419 JAN 1,456 10,658 3,492 12,695 7,874 17,078 FEB 1,234 9,010 2,943 109,959 7,006 14,782 MAR 1,111 8,130 2,620 9,637 6,295 13,314 APR 1,365 7,989 3,159 9,783 6,920 13,544 MAY 13,298 10,464 27,505 24,671 59,746 56,912 JUN 28,040 12,171 64,348 48,479 123,829 107,960 JUL 23,680 10,121 62,882 49,323 131,568 118,009 AUG 21,514 9,497 56,141 44,125 110 '242 98,225 SEP 13,254 7,804 32,494 27,044 65,674 60,225 * Susitna River ** Power flows (Case A Scenario) E-4-19 co ,... m .... I 0 lO 0) r-\ 0 0 0 .... X (/) 1.1.. 0 ._, UJ CJ a: fTl <: I :c +:a 0 I ~ N 0 0 >-_. :c 1-z 0 ::E z <( UJ :E 30 25 20 15 pre -proJect flows ~ 10 post -proJect power flows 5 OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP Figure E.4.9. Mean monthly pre-project (USGS 1977, 1978a, 1978b, 1979) and predicted (R&M 1982a, b) post-project power (Case A scenario) discharge (cfs) of the Susitna River at Gold Creek for the period 1950-1978. co ,.._ Q) .,... I 0 ll) Q) .... ...... 0 0 0 .... X fJ) LL 0 loJ w C) a: <( rr1 J: I 0 -+:> I !:2 N 0 _, >-_. J: 1-z 0 ::::E z <( w :E ) --J 60 50 40 pre -project flows 30 post -project power flows 20 10 OCT , NOV DEC JAN FEB MAR APR . MAY JUN JUL AUG SEP Figure E.4.10. Mean monthly pre-project (USGS 1977, 1978a, 1978b, 1979) and predicted (R&M 1982a) post-project power (Case A scenario) discharge (cfs) of the Susitna River at Sunshine for the period 1950-1978. .1 co ,._ en ..- I 0 lf) en r--. 0 0 0 ..- X (/) u_ 0 ....... w ('J 0: fl"1 <( I I .j::> 0 I ~ N N 0 >- _J I I-z 0 ~ z <( w :2: 150 125 100 75 pre -project flows post -project power flows 50 25 Susitna River At Susitna Station (AM 26) 0 L---~--~----~---L--~L---~--~----~---L----L----L--~~------~----~--------~ OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP Figure E.4.11. Mean monthly pre-project (USGS 1977, 1978a, 1978b, 1979) and predicted (R&M 1982a) post-project power (Case A scenario) discharge (cfs) of the Susitna River at Susitna Station for the period 1950-1978 . J . . ~ nl I +:> I N w J 0 0 0 X (/) LL 0 ~ ~ a:: <( I 0 (/) 0 40 35 30 25 20 15 10 5 0 • • 1950 1951 Predicted Postproject Discharge • • • • • 1952 1953 1954 1955 1956 Preproject Discharge -- n i! :, 'I lo .. r': I I (! I ! ( I I I 1957 1958 1959 YEAR --- Period of Adult Salmon Passage and Spawning ... 3 II ,. •• •' •' .: It •• II II !~ : ... I I I I • I 1 I I I I : I I I l • • 'I I, .. '·i I, ,, •• -li I• •' II J: ,, :~o i I I I i i :I I 1 ~ : i I I 1960 1961 1962 1963 1964 figure E.4.12. Mean monthly pre-project (USGS 1978a)and predicted (R&M 1982a) post-project power (Case A scenario) discharge (cfs) of the Susitna River at Gold Creek for the years 1950-1964 and provisional periodicity of adult salmon spawning and passage. l JTI I +:> I N ..p. 0 0 0 X (/) 1..1.. 0 UJ (!) cr <( :.c 0 ({) 0 40 35 30 25 20 15 lO 5 0 • Predicted PostprnJect Disch;trge • • --• - Preproject Discharge • fl II II ll ,, " II II II ,, " ., ~1 l l I ., I I I I I I I 1 • n II IO II " tj ' I I 1n u: I I I I I I I - • Period ol Adult Salmon Passc~oe and Spawnm9 • • • 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 Figure E.4.13. YEAR Mean monthly pre-project (USGS 1977, 1978a, 1978b, 1979) and predicted (R&M 1982a) post-project power (Case A scenario) discharge (cfs) of the Susitna River at Gold Creek for the years 1965-1978 and provisional of adult salmon spawning and passage. F ' - Gold Creek), and at their mouths when flows drop to approximately 10,000 cfs (see Section 2. 7 and ADF&G 198lc). Projected post-project average summer discharges at Gal d Creek never exceed 15,000 cfs, and during the period of major salmon passage (July-September) rarely exceed 10,000 cfs (Figures E.4.12 and E.4.13). This means a portion of the slough habitat would not be avail- able for salmon spawning at these streamflows because salmon passage into the sloughs would be hampered or eliminated. Periodic flood events have a flushing effect on the mainstem its side channels, and sloughs. The extent to which these periodic cleansing floods affect the fish habitat in the Susitna River is not well known, but changes in flushing events may constitute an impact to the fishery. Investigations to obtain a better understanding of these observed and pre- dicted relationships are planned for 1982. E-4-25 r ~ I I ..... r r I I"" I i' - 5. CONQLJSirn -i - - !""" ! 5. CONCLUSION It is hoped that this report provided an introduction to the scope and types of data collection programs presently being undertaken by the ADF&G as part of the APA•s Su-Hydro Environmental Feasibility Studies. Keeping in mind that this report .represents a partial synthesis of the 1981 fishery and aquatic habitat data collected, it is recommended that a contractor be designated to analyze these and other relevant data as part of a comprehensive aquatic studies impact analysis. All past and present reports related to the fishery and aquatic habitat characterization of the Susitna River should be included in this evaluation. New information should also be incorporated into this analysis as it becomes available. E-5-1 !!""' I - - r -I 6. CDNTRIBUTO~ - - - - - 6. CONTRIBUTORS AQUATIC HABITAT & INSTREAM FLOW PROJECT LEADER BIOMETRICIAN CREW LEADERS EDITORS GRAPHICS COORDINATOR DRAFTING 1. INTRODUCTION 2. FISHERIES AND HABITAT RELATIONSHIPS Salmon Periodicity and Sonar Counts in Relation to Discharge Percent Incidence of Selected Fish Species in Relation to Discharge Percent Trapping Incidence of Selected Fish Species in Relation to Point Specific Depth and Velocity Bering Cisco Spawning Habitat Evaluation Matrixes of Fishery and Physio- chemical Observations Chum and Sockeye Adult Salmon Observations in Selected Sloughs in Relation to Mainstem Discharge Fisheries and Habitat Relationships in the Proposed Impoundment Area E-6-1 Christopher Estes A 11 en Bingham Timothy Quane Andrew Hoffmann Christopher Estes All~n Bingham Camille Stephens ~Jendy Kirk Carol Riedner Kathy Sheehan Camille Stephens Sheryl Salasky Christopher Estes Allen Bingham Staff Drew Crawford Kevin Delaney Doug Lang Andrew Hoffmann Allen Bingham Christopher Estes Doug Lang Staff Timothy Quane Christopher Estes Joe Sautner - CONTRIBUTORS (Continued) - 3. HABITAT RELATIONSHIPS -Discharge and Turbidity Relationships Andrew Hoffmann Allen Bingham Differences Between Surface Water Staff -Temperatures at Mainstem Locations Diel Surface Water Temperature Andrew Hoffmann Fluctuations Selected Slough Habitat Studies Andrew Hoffmann Timothy Quane - Christopher Estes 4. PREDICTIVE MODELS Doug Lang Christopher Estes 5. CONCLUSION Staff - - - - - - - E-6-2 r .... [ r l r r I 7. ACKNOWLEDGEMENTS Many individuals representing s16te and federal agencies and the private sector provided support to this project and resultant report. The authors wish to especially thank T.W. Trent, L. Heckart, L. Bartlett, K. Delaney, B. Barrett, D. Schmidt, B. Dieryck, K. Watson and the AH, RJ, AA and Biometrics support staff (ADF&G); W. Trihey (ACRES); J. Baldridge (Arctic Environmental Information and Data Center); and, D. Lehner-Welch (Soil Conservation Service). The authors also wish to especially thank P. Skeers for typing. Special acknowledgement and appreciation are also extended to the APA for funding this first year of study. E-7-1 8. ffFEPENcr:S ,.... r - f""" I ! 8. REFERENCES Acres American, Inc. (Acres) 1980. Susitna Hydroelectric Project Plan of Study. Prepared for the Alaska Power Authority. Anchorage, Alaska. Acres American, Inc. (Acres) 1982. Susitna Hydroelectric Project feasibility report. Volume 4. Appendix A. Hydrological Status. Prepared by Acres for the Alaska Power Authority. Anchorage, Alaska. Alaska Department of Fish and Game (ADF&G). 1974. An assessment of the anadromous fish populations in the Upper Susitna River ~Jatershed between Devil Canyon and the Chulitna River. Anchorage, Alaska. 1976. Fish and Wildlife studies related to the Corps of Engineers Devil Canyon, Watana Reservoir Hydroelectric Project. ADF&G. Anchorage, Alaska. 1977. ?reauthorization assessment of the proposed Susitna Hydroelec- tric Projects: preliminary investigations of water quality and aquatic species composition. ADF&G. Anchorage, Alaska • ---. 1978. Preliminary environmental assessment of hydroelectric develop- ment on the Susitna River. Anchorage, Alaska. 1979. Preliminary final plan of study fish and studies proposed by the ADF&G. ADF&G. Anchorage, Alaska. E-8-1 - REFERENCES (Continued) - 198la. Adult anadromous phase 1 final species/subject report. ADF&G Su Hydro Aquatic Studies Program. Anchorage, Alaska. - 198lb. Adult anadromous phase 1 final stock separation feasibility report. AOF&G Su Hydro Aquatic Studies Program. Anchorage, Alaska. 198lc. Aquatic habitat and instream flow phase 1 final draft subject report. ADF&G Su Hydro Aquatic Studies Program. Anchorage, Alaska. 198ld. Juvenile species/subject report. Anchorage, Alaska. anadromous fish study phase AOF&G Su Hydro Aquatic 1 final draft Studies Program. 1981e. Procedures manual. (Draft) ADF&G Su Hydro Jl.quatic Studies Program. Anchorage, Alaska. 1981f. Resident fish investigation on the Jower Susitna River phase 1 final species/subject draft report. ADF&G Su Hydro Aquatic Studies Program. Anchorage, Alaska. - .... - - - 1981g. Resident fish investigation on the upper Susitna River phase - 1 final species/subject draft report. ADF&G Su Hydro Aquatic Studies Program. Anchorage, Alaska. E-8-2 """ i - - - """'~ I .... - REFERENCES (Continued) Alaska Department of Natural Resources (ADNR). bibliography. ADNR. Anchorage~ Alaska. 1979. Susitna River Basin bibliography. Anchorage~ Alaska. 1977. Susitna Basin Supplement. AONR. Baxter, R.M.~ and P. Glaude. 1980. Environmental effects of dams and impoundments in Canada: experience and prospects. Canadian Bulletin of Fisheries and Aquatic Sciences. Bulletin 205. Bishop, O.M. 1975. A hydrologic reconnaissance of the Susitna River below Devils Canyon. A report prepared for Nat. Marine Fish. Serv. of NOAA, Contract no. 03-4-208-302. Environaid~ Juneau, Alaska. Bovee, K.D. and T. Gochnauer. 1977. Probability of use Criteria. U.S. Fish and Wildlife Service. Instream Flow Group. Ft. Collins, Colorado. Hocutt, C.H., J.R. Stauffer, J.E. Edinger, L.W. Hall~ and R.P. Morgan. 1980. Powerplants -effects on fish and shellfish behavior. Academic Press . New York, New York. Hynes, H.B.N. 1970. The ecology of running waters. University of Toronto Press. Toronto, Canada. E-8-3 - REFERENCES (Continued) . ~ Morrow, J.E. 1980. The freshwater fishes of Alaska. Alaska Northwest Publishing Company. Anchorage, Alaska. -, R&M Consultants. Morphology. 1982a. Susitna Hydroelectric Project. Appendix 8.9. River Prepared for the A 1 ask a Power Authority. R&M Consultants. Anchorage, Alaska. 1982b. Unpublished provisional data. R&M Consultants. Anchorage, Alaska. Reiser, O.W. and T.C. Bjornn. 1979. Habitat requirements of anadromous sa lmonids. U.S. Department of Agriculture Forest Service. Pacific Northwest Forest and Range Experiment Station. General Technical Report. PNW-96. Portland, Oregon. Scott, W.B. and E.J. Crossman. 1973. Freshwater fishes of Canada. Bulletin Fisheries Research Board of Canada. 19(4). Trihey, W. 1982. Personal communication. Acres American Inc. Anchorage, Alaska. U.S. Geological Survey (USGS). 1977. Water resources data for Alaska water year 1976. Report number USGS/WRD/H0-77/043. Anchorage, Alaska. E-8-4 - - - - - - - - REFERENCES (Continued) 1978a. Surface water records of Cook Inlet Basin, Alaska, through September 1975. Open fi 1 e report. Number 78-498. ll.nchorage, A 1 aska. 1978b. Water resources data for Alaska, water year 1977. Report number USGS/WRO/HD-78/074. Anchorage, Alaska. 1979. Water resources data for Alaska, water year 1978. Report number USGS/WRD/H0-80/007. Anchorage, Alaska. 1981. provisional discharge and water quality data to be published in: Water Resources Data for Alaska, water year 1981. Anchorage, Alaska. Ward, J.V. and J.A. Stanford. 1979. The ecology of regulated streams. Plenum Press. New York, New York. E-8-5 9. .APPEND I X r ,.... - - - APPENDIX EA Head Pin and Cross Section Elevations - - - """' I The following data consists of head pin and cross sectional elevations, measured in feet, for five Susitna River sloughs (SA, 9, 168, 19 and 21) studied during the 1981 field season (ADF&G 1981c). One table of head pin data exists for each slough and one table of cross section elevation data exists for each transect in each of the sloughs. There are different numbers of transects in each slough; the break down was as follows: BA-7, 9-9, 168-17, 19-10, and 21-17. Two head pins were established for each transect, one on each side of the stream channel. The head pin tables include elevations for all head pins surveyed in each slough. Left and right banks were determined looking upstream. Headings for the head pin elevation tables are: Bench Mark, Elevation and True Elevation. Bench Mark refers to the location (i.e. head pin, temporary bench mark, or ground) where an elevation was determined. Elevation refers to the height, in feet, of that particular location in reference to a temporary bench mark established by the ADF&G prior to tying into R&M datum. True elevation refers to the elevation of a location in reference to an R&M transect (feet above mean sea level). Headings for the cross section tables are the same except that Bench r~ark is replaced by Station. Station refers to the distance from the head pin established as 0.0 feet. The mainstem water surface elevations were determined at the head portions of sloughs 8A, 9, 168 and 21 with the exception of transect 5 of Slough 8A where the mainstem water surface elevation was not measured. At Slough 19, the mainstem water surface elevation was determined at the mouth of the slough because there is no head. The mainstem water surface elev~tions are listed in the head pin elevation table for sloughs 168, 19 and 21. Water surface elevations for sloughs SA and 9 are listed with the cross section elevations. For the sake of brevity, abbreviations have been used in the tables. The -abbreviations are as follows: - - I TBM LBHP 1 RBHP GB LWS RWS LWE RWE R&M LRX 32 -temporary bench mark. left bank head pin for transect number 1 right bank head pin ground beside the head pin previously listed left bank water surface -right bank water surface left bank waters edge -right bank waters edge lower river cross section (downstream of Devil Canyon) number 32 established by R&M consultants. EA-1 -~ - EA-2 - - Table EA-2. Cross section el~vJtiohs in transect 1 (first head) of Slough 8A, surveyed October 10, 1981. Transect dewatered. Station 0.0 LBHP 1 0.0 GB 7. 7 Bankfull 15.5 18.5 21.9 26.2 31.4 39.1 46.4 48.0 Mainstem RWS 50.2 52.6 54.9 57.4 59.0 65.0 67.1 68.8 Bankfull 78.0 GB 78.0 RBHP 1 Elevation 100.45 100.13 99.96 93.80 94.37 94.86 95.54 96.15 96.44 97.72 93.31 96.37 96.05 96.35 96.68 97.64 97.66 99.13 99.92 99.95 100.35 True Elevation 586.91 586.59 586.42 580.26 580.83 581.32 582.0b 582.61 582.90 584.18 579.77 582.83 582.51 582.81 583.14 584.10 584.12 585.59 586.38 586.41 586.81 Provisional mainstem Susitna River discharge recorded at Gold Creek on October 10, 1981 was 9, 700 cfs (USGS 1981). EA-3 Table EA-3. Cross section elevations in transect 2 (second head) of Slough 8A, surveyed October 10, 1981. Transect was dewatered. Station Elevations True Elevation 0.0 LBHP 2 99.35 585.81 0.0 GB 98.96 585.42 11.3 99.31 585.77 21.1 98.69 585.15 26.6 Bankfull 98.61 585.07 37.2 97.85 584.31 48.5 97.34 583.80 57.4 97.14 583.60 70.8 97.45 583.91 77.8 96.74 583.20 88.3 97.30 583.76 95.2 97.57 584.03 103.4 94.41 583.87 116.8 97.85 584.31 125.5 97.77 584.23 131.3 97.31 583.77 137 0 9 97.03 583.49 150.9 97.19 583.65 166.3 97.31 583.77 170.5 97.04 583.05 137.8 97.45 583.91 194.1 97.04 583.50 199.9 96.74 583.20 207.0 97.11 583.57 233.2 97.11 583.57 247.6 97.05 583.51 257.6 96.83 583.29 269.4 97.16 583.62 264.3 96.86 583.32 300.0 Mainstem RWS 92.18 578.64 328.5 96.70 583.16 336.0 96.40 582.86 381.7 96.40 582.86 396.3 96.75 583.21 427.6 96.75 583.21 443.9 96.30 582.76 452.7 97.03 583.49 463.4 97.33 583.79 480.4 97.61 584.07 486.7 97.65 584.11 490.6 Bankfull 98.24 584.70 497.3 98.98 585.44 507.0 GB 99.77 586.23 507.0 RBHP 2 100.12 586.58 Provisional Susitna River mainstem discharge recorded at Gold Creek on October 10, 1981 was 9,700 cfs (USGS 1981}. EA-4 - - - - """"' - - ~ - ~ - - - ~ - -· Table EA-4. Cross section ei,~vations in transect 3 (third head) of Slough 8A, surveyed October 10, 1981. Transect was dewatered. Station 0.0 LBHP 3 0.0 GB 11.8 21.5 Bankfull 24.6 26.4 34.5 45.0 48.3 52.4 56.4 61.7 70.6 81.2 86.0 Mainstem RWS* 91.4 99.7 107.6 111.6 116.0 119.1 121.5 123.4 125.8 129.0 131.2 BankfUll 138.2 147.1 GB 147.1 RBHP 3 Elevation 98.97 98.60 98.33 97.66 96.95 95.97 94.42 93.83 95.02 94.81 94.59 95.03 95.22 95.30 90.85 95.20 94.86 94.71 94.52 94.61 95.04 95.70 96.06 96.31 97.09 97.85 98.43 98 .. 69 99.02 True Elevation 585.43 585.06 584.79 584.12 583.41 582.43 580.88 580.29 581.48 581.27 581.05 581.49 581.68 581.76 577.31 581.66 581.32 581.17 580.98 581.07 581.50 582.16 582.52 582.77 583.55 584.31 584.89 585.15 585.48 Provisional mainstem Susitna River discharge recorded at Gold Creek on October 10, 1981 was 9,700 cfs (USGS 1981). * A right bank mainstem water surface elevation of 577.31 ft was determined at 334° magnetic north at an unknown distance from transect station 86. EA-5 Table EA-5. Cross section elevations in transect 4 (fourth head) of Slough 8A, surveyed October 10, 1981. Transect was dewatered. ~ Station Elevation True Elevation ~ 0.0 LBHP 4 96.97 583.43 0.0 GB 96.55 583.01 3.7 96.24 582.70 19.2 95.61 582.07 41.6 95.44 581.90 46.5 95.37 581.83 49.7 94.96 581.42 53.5 94.58 581.04 59.0 94.13 580.59 69.0 93.64 580.10 ,.,.,. 74.8 94.02 580.48 77.5 94.67 581.13 80.8 94.96 581.42 -116.7 94.93 581.39 145.9 95.09 581.55 146.0 Mainstem RWS 90.35 576.81 168.4 94.66 581.12 184.4 94.49 580.95 200.8 94.55 581.01 221.7 94.80 585.26 ..... 228.8 95.11 581.57 233.2 95.31 581.77 236.0 95.68 582.14 237.4 96.38 582.84 ~ 240.3 96.57 583.03 242.4 Bankfull 97.20 583.66 246.9 97.44 583.90 -255.0 98.22 584.68 259.9 GB 98.32 584.78 259.9 RBHP 4 98.73 585 .19 - Provisional mainstem Susitna River discharge recorded at Gold Creek on October 10, 1981 was 9,700 cfs (USGS 1981). .., - - EA-6 -Table EA-6. Cross section ef~vations in transect 5 (fifth head) of Slough 8A, surveyed October 11, 1981. Transect was dewatered. """" Station Elevation True Elevation 0.0 LBHP 5 96.62 583.08 0.0 GB 96.10 582.56 5.0 Bankfull 95.91 582.37 8.2 93.75 580.21 10.1 92.91 579.37 13.5 91.81 578.27 16.3 91.21 577.67 19.5 90.52 576.98 24.1 90.30 576.76 ~ 28.8 91.07 577.53 31.1 90.40 576.86 34.8 90.04 577.50 39.3 89.60 576.06 45.7 88.53 574.99 47.3 88.82 575.28 50.4 88.51 574.97 -52.4 89.15 575.61 55.2 89.79 576.25 57.7 90.59 577.05 61.5 90.27 576.73 63.6 90.65 577.11 66.9 89.95 576.41 70.3 89.28 575.94 74.2 89.65 576.11 78.3 90.01 576.47 81.9 90.16 576.62 84.0 89.75 576.21 86.5 89.87 576.33 88.7 89.05 575.51 90.7 88.20 574.66 93.0 87.56 574.02 95.0 87.28 573.74 98.7 87.77 5.74. 23 :""' 100.9 88.71 575.17 102.3 89.10 575.56 104.2 89.45 575.91 106.1 89.31 575.77 -108.0 88.59 575.05 109.3 88.08 574.54 110.7 87.02 573.48 114.7 87.08 573.54 116.1 87.80 574.26 118.4 87.42 573.88 121.8 87.08 573.54 126.3 86.71 573.17 129.5 86.94 573.40 140.3 86.78 573.24 EA-7 Table EA-6. (Continued). - -· Station Elevation True Elevation 147.8 87.15 573.61 153.3 87.13 573.59 ,.,., 156.0 87.49 573.95 164.0 87.68 574.14 170.6 88.12 574.58 -175.5 88.49 574.95 178.5 88.31 574.77 182.0 88.84 575.30 ·~ 185.5 88.28 574.75 187.3 88.20 574.66 188.7 88.63 575.09 194.9 88.66 575.12 ~ 198.1 88.97 575.43 202.7 88.57 575.03 208.4 88.79 575.25 211.7 88.33 574.79 216.2 89.35 575.81 217.2 90.47 576.93 218.6 Bankfull 91.26 577.72 - 226.1 GB 91.76 578.22 226.1 RBHP 5 92.22 578.68 !""'! Provisional mainstem Susitna River discharge recorded at Gold Creek on October 11, 1981 was 8,820 cfs (USGS 1981). - - - - - EA-8 - - - - Table EA-7o Cross section elevations in transect 6 (sixth head) of Slough 8A, surveyed October 10, 1981o Transect was dewateredo Station OoO LBHP 6 OoO GB 14 o 0 Bankfu 11 33o6 58o3 105 0 3 123o4 170o5 181.0 ~1a in stem RWS 194o5 222.5 240.3 257.3 269.1 278o4 286o9 291.2 294o3 Bankfull 298o4 304o0 309o0 314o1 GB 314o1 RBHP 6 Elevation 89o93 89o39 89o20 88028 87o61 87o36 86o98 87o01 82o56 86.57 86o93 87o31 86o84 86.73 87 0 77 88o63 88o93 90o11 90o69 91.34 91.91 91.81 92o31 True Elevation 576.39 575.85 575o66 574.74 574.07 573o82 573.44 573.47 569.02 573.03 573.39 573.77 573.30 573.19 574.23 575o09 575o39 576.57 447o15 577.80 578.37 578o27 578.77 Provisional mainstem Susitna River discharge recorded at Gold Creek on October 10, 1891 was 9,700 cfs {USGS 1981)o EA-9 Table EA-8. Cross section elevations in transect 7 (mouth) of Slough 8A, surveyed October 10, 1981. - Station Elevation True Elevation 0.0 LBHP 7 80.10 566.56 0.0 GB 79.63 566.09 11.7 Bankfull 79.75 566.21 16.3 78.92 565.38 22.0 77.75 564.21 28.2 77.01 563.47 36.6 76.64 563.10 38.9 76.67 563.13 44.8 75.94 562.40 53.6 75.90 562.36 62.8 75.79 562.25 -100.5 LWE 74.61 561.07 100.5 LWS 74.65 561.11 112.4 74.30 560.76 ~ 131.6 73.92 560.38 141.7 73.43 559.89 156.3 73.02 559.48 165.6 72.66 559.12 - 171.6 72.47 558.93 178.0 72.13 558.59 181.0 73.14 559.60 ~ 183.1 RWE 74.58 561.04 183.1 RWS 74.67 561.13 185.8 76.26 562.72 190.6 Bankfull 82.01 568.47 194.1 GB 82.06 568.52 194.1 RBHP 7 82.54 569.00 IIBP, Provisional mainstem Susitna River discharge recorded at Gold Creek on October 10, 1981 was 9,700 cfs (USGS 1981). ~ - I~ EA-10 - - - - - Table EA-9. Head pin elevations in Slough 9, surveyed October 12-14, 1981. Bench Mark Elevation True Elevation TBM 100.00 608.33 LBHP 1 (Head) 100.16 608.49 GB 99.74 608.07 RBHP 1 (Head) 100.83 609.16 GB 100.31 608.64 LBHP 2 101.37 609.70 GB 100.96 609.29 RBHP 2 97.55 605.88 GB 97.15 605.48 LBHP 3 93.06 601.39 GB 92.51 600.84 RBHP 3 92.27 600.60 GB 91.76 600.09 LBHP 4* 91.84 600.17 GB 91.46 599.79 RBHP 4* 89.11 597.44 GB 88.71 597.14 LBHP 5 (Mouth) 89.37 597.70 GB 89.98 597.31 RBHP 5 (Mouth) 91.34 599.67 GB 90.78 599.11 R&~1 LRX 32 100.39 608.72 * Transect 4 was located on the R&M LRX 31. EA-11 Table EA-10. Cross section elevation in transect 1 (Head) of Slough 9, surveyed October 14, 1981. Transect was dewatered. Station Elevation True Elevation 0.0 LBHP 1 100.15 608.48 0.0 GB 99.71 608.04 5.4 99.45 607.78 8.2 Bankfull 98.73 607.06 9.1 97.24 605.57 11.0 96.60 604.93 13.3 96.02 604.35 15.9 95.57 603.40 25.8 95.93 604.26 33.8 95.20 603.53 39.3 95.64 603.97 79.0 Mainstem R~/S 91.58 599.91 98.8 96.19 604.52 111.8 95.61 603.94 140.7 96.13 604.46 149.3 96.08 604.43 176.1 96.35 604.68 195.2 95.97 604.30 206.7 95.52 603.85 221.7 96.16 604.49 238.0 96.52 604.85 244.9 96.29 604.62 255.6 96.62 604.95 257.0 96.15 604.48 258.4 96.45 604.78 263.0 96.80 605.13 273.1 97.14 605.47 284.1 97.53 605.80 289.4 97.19 605.52 291.9 97.31 605.64 298.7 97.47 605.80 301.4 97.57 605.90 304.1 97.03 605.36 310.0 96.12 604.45 335.0 95.87 604.20 336.3 95.61 603.94 341.2 95.91 604.24 370.3 95.99 604.32 376.2 93.36 604.69 381.0 95.74 604.07 384.4 94.89 603.22 391.0 94.05 602.38 393.6 93.82 602.15 398.4 94.12 602.45 400.3 94.90 603.23 402.4 95.43 603.76 EA-12 ~ ~ - ~ - - - - - - - - - .- - - - - -' Table EA-10. (Continued). Station 404.2 410.8 413.0 414.5 Bankfull 418.3 423.0 GB 423.0 RBHP 1 Elevation 95.98 94.32 98.19 99.29 100.56 100.26 100.81 True Elevation 604.31 602.65 606.52 607.62 608.89 608.59 699.14 Provisional mainstem Susitna River discharge recorded at Gold Creek on October 14, 1982 was 7,290 cfs (USGS 1981). EA-13 Table EA-11. Cross section elevations in transect 2 of Slough 9, surveyed October 14~ 1981. Transect was dewatered. - Station Elevation True Elevation 0.0 LBHP 2 101.37 609.70 -0.0 GB 100.93 609.26 8. 7 Bankfull 101.57 609.90 9.7 99.96 608.29 -12.0 98.96 607.29 16.1 96.59 604.92 19.8 94.82 603.15 23.2 93.94 602.27 ~' 25.0 93.81 602.14 26.5 93.37 601.70 33.0 93.62 601.95 .... 34.0 93.96 602.29 41.4 94.07 602.40 56.4 93.79 602.12 67.5 94.03 602.36 96.1 93.09 601.42 106.6 93.40 601.73 118.3 93.53 601.86 ~ 133.4 93.32 601.65 141.7 93.39 601.72 147.3 93.85 602.18 154.1 93.87 602.20 161.8 93.28 601.61 174.1 93.33 601.66 186.3 93.77 602.10 195.3 93.93 602.26 200.9 93.72 602.05 206.1 93.91 602.24 -221.4 93.80 602.13 224.9 93.57 601.90 235.4 93.77 602.10 241.8 93.49 601.82 251.7 93.39 601.72 262.8 94.27 602.60 269.8 95.08 603.41 274.3 96.21 604.54 279.8 Bankfull 97.15 605.48 281.3 GB 97.13 605.46 281.3 RBHP 2 97.55 605.88 Provisional mainstem Susitna River discharge recorded at Gold Creek for October 14, 1981 was 7,290 cfs (USGS 1981). .... - EA-14 -Table EA-12. Cross section ~Tevations in transect 3 of Slough 9, surveyed October 14, 1981. - Station Elevation True Elevation -0.0 LBHP 3 93.05 601.38 0.0 GB 92.49 600.82 3.1 Bankfull 92.35 600.66 11.2 91.40 599.73 22.8 91.38 599.71 28.2 90.95 599.28 37.6 90.87 599.20 47.0 90.02 598.35 49.6 89.61 597.94 52.0 89.95 598.28 56.0 89.69 598.02 65.4 89.93 598.26 69.7 90.13 598.46 75.4 89.47 597.80 81.5 88.64 596.97 89.4 88.50 596.83 100.6 88.27 596.60 113.5 87.48 595.81 124.6 87.04 595.37 138.5 86.58 594.91 163.3 86.58 594.91 -183.9 86.33 594.66 197.0 LWS 86.08 594.41 197.0 LWE 86.06 594.39 203.0 85.83 594.16 206.8 85.94 594.27 210.0 85.85 594.18 215.1 85.68 594.01 219.2 RWS 85.93 594.26 219.2 RWE 85.92 594.25 222.6 86.37 594.70 -227.3 86.21 594.54 238.7 86.95 595.28 242.0 88.98 597.31 -245.2 Bankfull 91.61 599.94 252.1 GB 91.75 600.08 252.1 RBHP 3 92.25 600.58 Provisional mainstem Susitna River discharge recorded for October 14, 1982 at Gold Creek was 7,290 cfs (USGS 1981). ~ EA-15 Tab 1 e EA-13. Cross section elevation in transect 4 of Slough 9, surveyed October 14, 1981. ~ Station Elevation True Elevation 0.0 LBHP 4 91.84 600.17 -0.0 GB 91.44 599.77 3. 3 Bankfull 91.40 599.73 4.1 90.06 598.39 ~ 11.5 87.95 596.68 12.8 85.61 593.94 22.0 84.73 593.06 26.0 LWS 84.21 592.54 26.0 LWE 84.21 592.54 31.0 84.06 592.39 33.6 84.15 592.48 -37.8 83.93 592.26 42.8 83.60 591.93 48.2 83.33 591.66 50.7 83.62 591.95 61.1 83.77 592.10 74.6 RWS 84.27 592.60 74.6 RWE 84.17 592.50 .... 83.9 84.37 592.70 98.1 84.59 592.92 105.7 84.34 592.67 .... 122.1 84.73 593.06 138.9 85.28 593.61 143.6 85.88 594.21 144.9 85.91 594.24 ~' 146.5 86.45 594.78 148.4 Bankfull* 87.36 595.69 159.0 87.40 595.73 ~ 173.6 87.35 595.68 184.3 87.89 596.22 187.4 88.51 596.84 191.2 GB 88.73 597.06 191.2 RBHP 4 89.13 597.46 Provisional mainstem Susitna River discharge recorded at Gold Creek on October 14, 1981 was 7,290 cfs (USGS 1981). * Located in a flood plain. ""' - EA-16 - .... - Table EA-14. Cross section elevat~ons in transect 5 (Mouth) of Slough 9, surveyed October 14, 1981. Station 0.0 LBHP 5 0.0 GB 2 • 0 Bank fu 11 4.6 7.6 12.1 15.1 17.5 21.9 33.2 42.0 47.4 53.9 67.3 81.3 90.4 103.1 112.0 130.0 146.6 167.7 181.9 188.1 188.8 LWS 188.8 LWE 194.3 204.8 209.9 215.8 RWS 215.8 RWS 216.3 221.2 226.9 231.4 Bankfull 238.2 GB 238.2 RBHP 5 Elevation 89.37 88.96 88.89 87.96 87.31 86.47 85.65 85.00 85.34 85.74 85.31 84.99 85.39 84.21 83.28 83.06 83.14 82.89 83.02 83.21 83.00 82.78 82.70 82.41 82.34 81.94 81.99 82.31 82.39 82.33 82.42 82.98 85.37 90.65 90.74 91.34 True Elevation 597.70 597.29 597.22 596.29 595.64 594.80 593.98 593.33 593.67 594.07 593.64 593.32 593.72 592.54 591.71 591.39 591.47 591.22 591.35 591.54 591.33 591.11 591.03 590.74 590.67 590.27 590.32 590.64 590.72 590.66 590.75 591.31 593.70 598.98 599.07 599.67 Provisional mainstem Susitna River discharge recorded at Gold Creek on October 14, 1981 was 7,290 cfs (USGS 1981). EA-17 Table EA-15. Head pin elevations in Slough 168, surveyed September 9, 10, 16, and 17, 1981. Bench Hark Elevation True Elevation TBM 100.00 708.02 LBHP 1 (Mouth) 95.47 703.49 GB 94.96 702.98 RBHP 1 (Mouth) 93.30 701.32 GB 92.89 700.91 LBHP 2 95.96 703.98 GB 95.69 703.71 RBHP 2 95.28 703.30 GB 94.87 702.89 LBHP 3 96.24 704.26 GB 95.85 703.87 RBHP 3 96.22 704.24 GB 95.84 703.86 LBHP 4 96.25 704.27 GB 95.93 703.95 RBHP 4 96.58 704.60 GB 96.15 704.17 LBHP 5 96.31 704.33 GB 96.00 704.02 RBHP 5 96.54 704.56 GB 96.22 704.24 LBHP 6 96.60 704.62 GB 96.25 704.27 RBHP 6 95.89 703.91 GB 95.53 703.55 LBHP 7 96.97 704.99 GB 96.49 704.51 RBHP 7 96.57 704.59 GB 96.14 704.16 LBHP 8 96.76 704.78 GB 96.41 704.43 RBHP 8 97.37 705.39 GB 97.06 705.08 LBHP 9 97.52 705.54 GB 97.06 705.08 RBHP 9 96.86 704.88 GB 96.49 704.51 LBHP 10 96.71 704.73 GB 96.29 704.31 RBHP 10 97.52 705.54 GB 97.13 705.15 LBHP 11 98.54 706.56 GB 97.92 705.94 RBHP 11 97.24 705.26 GB 96.85 704.87 EA-18 - ... ~ '""1 IJH!!' I ! - P""' I ..... - llf,;,jl! - .... Table EA-15. (Continued). ""'' Bench Mark Elevation True Elevation LBHP 12 100.45 708.47 ~,.. GB 100.01 708.30 RBHP 12 98.16 706.18 GB 97.75 705.77 ·-LBHP 13 100.04 708.06 GB 99.61 707.63 RBHP 13 98.85 706.87 GB 98.33 706.35 LBHP 14 99.09 707.11 GB 98.68 706.70 RBHP 14 98.58 706.60 r GB 98.23 706.25 ' LBHP 15 103.20 711.22 GB 102.82 710.84 RBHP 15 98.79 706.81 -GB 98.42 706.44 LBHP 16 103.74 711.76 GB 103.19 711.21 -RBHP 16 98.89 706.91 GB 98.49 706.51 LBHP 17 (Head) 100.00 708.02 GB 99.61 707.63 RBHP 17 (Head) 100.65 708.67 GB 100.19 708.21 R&M LRX 49 125.38 733.40 Mainstem RWS* on LRX 49 82.12 690.14 ~lainstem LWS* on LRX 49 93.82 701.84 * Left and right bank mainstem Sustina River water surface elevations on R&M LRX 49 were surveyed on September 17, 1981. EA-19 Table EA-16. Cross section elevations in transect 1 (Mouth) of Slough 16B, surveyed September 9, 1981. - Station Elevation True Elevation 0.0 LBHP 1 95.47 703.49 -0.0 GB 94.96 702.98 2.0 94.41 702.43 5.0 93.68 701.70 -7.0 92.79 700.81 10.0 92.53 700.55 12.0 92.28 700.30 16.0 91.72 699.74 19.0 91.30 699.32 22.0 91.02 699.04 25.0 90.80 698.82 30.0 90.56 698.58 35.0 90.36 698.38 40.0 90.02 698.04 45.0 89.78 697.80 50.0 89.64 697.66 56.0 LWS 89.22 697.24 56.0 LWE 89.42 697.44 ~~ 59.0 89.27 697.29 62.0 89.03 697.05 64.0 88.89 696.91 66.0 88.86 696.88 68.0 88.73 696.75 70.0 88.70 696.72 72.0 88.60 696.62 ~ 74.0 88.48 696.50 76.0 88.37 696.39 77.6 88.38 696.40 -78.5 88.63 696.65 79.8 RWS 89.21 697.23 79.8 RWE 89.13 697 .15 84.9 92.15 700.17 -95.3 92.89 700.91 95.3 GB 93.30 700.91 95.3 RBHP 1 93.30 701.32 .... Provisional mainstem Susitna River discharge recorded at Gold Creek on September 9, 1981 was 14,500 cfs (USGS 1981). ..... ~· EA-20 - Table EA-17. Cross section elevations in transect 2 of Slough 16B, surveyed September 17, 1981. Station 0.0 LBHP 2 0.0 GB 8.0 Bankfull 14.0 32.7 52.6 LWE 52.6 LWS 61.8 67.7 75.5 81.5 RWE 81.5 RWS 84.5 Bankfull 88.8 GB 88.8 RBHP 2 Elevation 95.96 95.69 94.47 93.29 91.01 89.19 89.22 88.69 87.95 88.46 89.02 89.22 94.62 94.87 95.28 True Elevation 703.98 703.71 702.49 701.31 699.03 697.21 697.24 696.71 695.97 696.48 697.04 697.24 702.64 702.89 703.30 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 17, 1981 was 11,300 cfs (USGS 1981). EA-21 Table EA-18. Cross section elevations in transect 3 of Slough 16B, surveyed September 16, 1981. Station Elevation True Elevation 0.0 LBHP 3 96.24 704.26 0.0 GB 95.85 703.87 5.0 95.26 703.28 8.3 Bankfull 94.00 702.02 13.0 92.73 700.75 28.6 90.19 698.21 33.4 90.26 698.28 46.5 LWS 89.36 697.38 46.5 LWE 89.63 697.65 58.1 88.82 696.84 60.3 RWS 89.27 697.29 60.3 RWE 89.27 697.29 64.2 90.23 698.25 68.6 89.52 697.54 76.2 78.0 94.89 702.91 80.1GB 95.84 703.86 80.1 RBHP 3 96.22 704.24 Provisional mainstem Susitna River discharge recorded at Gold Creek in September 16, 1981 was 11,300 cfs (USGS 1981). ---Data not collected. EA-22 - - - - - - - - - -I I - Table EA-19. Cross section elevations in transect 4 of Slough 168, surveyed September 16, 1981. Station 0.0 LBHP 4 0.0 GB 5.0 9.1 Bankfull 17.8 25.5 UJE 25.5 LWS 30.0 39.2 56.1 68.8 RWE 68.8 RWS 83.6 94.2 98.9 99.5 Bankfull 104.4 GB 104.4 RBHP 4 Elevation 96.25 95.93 95.48 94.69 92.72 90.04 90.03 89.48 89.89 89.89 89.92 89.90 90.38 92.45 94.12 95.85 96.15 96.58 True Elevation 704.27 703.95 703.50 702.71 700.74 698.06 698.05 697.50 697.91 697.91 697.94 697.92 698.40 700.47 702.14 703.87 704.17 704.60 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 16, 1981 was 11,300 cfs (USGS 1981). EA-23 Table EA-20. Cross section elevations in transect 5 of Slough 16B, surveyed September 16, 1981. Station Elevation True Elevation 0.0 LBHP 5 96.31 704.33 0.0 GB 96.00 704.02 2.6 96.23 704.25 3.8 Bankfull 96.40 704.42 5.7 93.39 701.41 9.2 91.64 699.66 10.0 LWE 89.83 697.85 10.0 LWS 90.03 698.05 16.2 89.08 697.10 24.1 88.96 696.98 36.4 RWE 90.05 698.07 36.4 RWS 90.02 698.04 46.1 90.65 698.67 54.5 91.42 699.44 70.0 91.65 699.67 77.7 93.11 701.13 84.1 94.31 702.33 88.6 Bankfu 11 95.62 703.64 93.9 GB 96.22 704.24 93.9 RBHP 5 96.54 704.56 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 16, 1981 was 11,300 cfs (USGS 1981). EA-24 - - - - - - - - - .... ' - Table EA-21. Cross section elevations in transect 6 of Slough 168, surveyed September 16, 1981. Station 0.0 LBHP 6 0.0 GB 1.4 2.9 Bankfull 4.5 8.1 LWS 8.1 LWE 16.2 23.0 29.8 RWS 29.8 RWE 41.5 61.6 70.8 77.7 81.8 86.7 Bankfull 90.4 GB 90.4 RBHP 6 Elevation 96.60 96.25 96.04 95.71 91.27 90.02 90.11 89.42 89.64 90.03 90.10 90.86 91.82 91.94 92.98 94.41 95.58 95.53 95.89 True Elevation 704.62 704.27 704.06 703.73 699.29 698.04 698.13 697.44 697.66 698.05 698.12 698.88 699.84 699.96 701.00 702.43 703.60 703.55 703.91 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 16, 1981 was 11,300 cfs (USGS 1981) . EA-25 Table EA-22. Cross section elevations in transect 7 of Slough 168, surveyed September 16, 1981. Station Elevation True Elevation 0.0 LBHP 7 96.97 704.99 0.0 GB 96.49 704.51 3.0 96.27 704.29 4. 3 Bankfull 95.85 703.87 6.4 91.31 699.33 17.1 LWE 90.30 698.32 17.1 LWS 90.35 698.37 24.5 89.94 697.96 35.1 90.54 698.56 43.3 RWE 90.67 698.38 43.3 RWS 90.36 698.69 53.2 91.08 699.10 62.5 91.47 699.49 67.4 91.92 699.94 71.1 93.33 701.35 75.5 94.61 702.63 78.2 Bankfull 96.07 704.09 79.5 GB 96.14 704.16 79.5 RBHP 7 96.57 704.59 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 16, 1981 was 11,300 cfs {USGS 1981). EA-26 - - .. )> ~ ~ - .... - - - - - - - 1""" - - - Table EA-23. Cross section elevations in transect 8 of Slough 168, surveyed September 16, 1981. Station Elevations True Elevation 0.0 LBHP 8 96.76 704.78 0.0 GB 96.39 704.41 3.4 96.38 704.40 5.7 Bankfull 96.22 704.24 7.2 94.10 702.12 8.9 83.32 701.34 11.7 92.40 700.42 14.6 LWE 91.21 699.23 14.6 LWS 91.22 699.24 17.1 91.00 699.02 26.1 90.81 698.83 34.5 90.98 699.00 40.1 90.99 699.01 49.0 90.87 698.89 56.6 90.41 698.43 60.7 90.87 698.89 67.9 RWE 91.05 699.07 67.9 RWS 91.20 699.22 69.0 92.13 700.15 72.8 93.37 701.39 74.7 Bankfull 96.27 704.29 77.5 96.83 704.85 83.4 GB 97.06 705.08 83.4 RBHP 8 97.36 705.38 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 16, 1981 was 11,300 cfs (USGS 1981). EA-27 Table EA-24. Cross section elevations in transect 9 of Slough 168, -surveyed September 16, 1981. - Station Elevation True Elevation 0.0 LBHP 9 97 .52. 705.54 ~· 0.0 GB 97.06 705.08 2.7 96.45 704.47 3.6 Bankfull 96.32 704.34 I'!!'W~ 6.4 95.37 703.39 9.7 94.50 702.50 11.7 94.07 702.09 14.0 93.36 701.38 -16.6 92.43 700.45 19.6 91.65 699.67 26.1 91.31 699.33 27.2 LWE 91.18 699.20 27.2 LWS 91.22 699.24 31.7 91.05 699.07 40.2 90.96 698.98 -44.9 90.92 698.94 50.8 90.85 698.87 53.4 90.57 698.59 ~ 58.6 90.50 698.52 60.0 90.29 698.31 63.9 90.34 698.36 68.0 90.55 698.57 - 69.6 R~/E 91.06 699.08 69.6 RWS 91.22 699.24 69.9 91.44 699.46 -71.4 92.28 700.30 72.6 Bankfull 95.42 703.44 74.3 96.52 704.54 """" 76.6 96.79 704.81 79.0 GB 96.49 704.51 79.0 RBHP 9 96.86 704.88 -Provisional mainstem Susitna River discharge recorded at Gold Creek on September 16, 1981 was 11,300 cfs (USGS 1981). - EA-28 - - - - ~- -~ - Table EA-25. Cross section elevations in transect 10 of Slough 168, surveyed September 16, 1981. Station 0.0 LBHP 10 0.0 GB 1.6 2.0 Bankfull 4.0 5.6 7.3 LWE 7.3 LWS 11.0 16.1 22.9 25.6 26.9 30.7 33.8 37.1 RWE 37.1 RWS 44.7 50.0 55.1 60.3 61.9 64.5 67.0 69.1 Bankfull 70.5 72.0 GB 72.0 RBHP 10 Elevation 96.71 96.29 96.04 95.52 92.65 91.41 91.21 91.70 91.21 90.89 90.82 90.95 90.75 91.05 91.15 91.21 91.70 91.67 91.93 92.12 92.13 92.65 93.07 93.81 95.69 96.96 97.13 97.52 True Elevation 704.73 704.31 704.06 705.54 700.67 699.43 699.23 699.72 699.23 698.91 698.84 698.97 698.77 699.07 699.17 699.23 699.72 699.69 699.95 700.14 700.15 700.67 701.09 701.83 703.71 704.98 705.15 705.54 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 16, 1981 was 11,300 cfs (USGS 1981). EA-29 ~--------------- Table EA-26. Cross section elevations in transect 11 of Slough 168, -surveyed September 16, 1981. - Station Elevation True Elevation 0.0 LBHP 11 98.54 706.56 -0.0 GB 97.92 705.94 2.0 97.31 705.33 3.9 Bankfull 96.79 704.81 -4.3 93.86 701.88 7.8 92.53 700.55 11.4 92.13 700.15 15.0 LWE 91.66 699.68 ~ 15.0 LWS 91.70 699.72 17.9 91.48 699.50 20.5 91.54 699.56 -. 26.6 91.30 699.32 ' 30.7 91.47 699.49 33.5 RWE 91.63 699.65 33.5 RWS 91.70 699.72 39.9 92.04 700.06 46.1 92.37 700.39 51.0 92.61 700.63 -56.3 92.82 700.84 63.6 92.89 700.91 70.7 93.02 701.04 73.4 93.38 701.40 .... 75.4 94.34 702.36 77.3 95.07 703.09 79.9 95.54 703.56 -81.4 Bankfull 96.38 704.40 82.7 GB 96.85 704.87 82.7 RBHP 11 97.24 705.26 - Provisional mainstem Susitna River discharge recorded at Gold Creek on September 16, 1981 was 11,300 cfs (USGS 1981). - - EA-30 -Table EA-27. Cross section elevations in transect 12 of Slough 168, surveyed September 16, 1981. ~ Station Elevation True Elevation -0.0 LBHP 12 100.45 708.47 0.0 GB 100.01 708.03 3.0 99.15 707.17 -6.0 Bankfull 97.81 705.83 7.0 95.64 703.66 9.5 94.64 702.66 15.8 93.19 701.21 I'-20.6 92.48 700.50 25.1 LWE 91.98 700.00 25.1 LWS 92.24 700.26 27.3 91.99 700.01 32.8 91.93 699.95 38.2 91.88 699.90 42.9 92.08 700.10 -47.5 92.11 700.13 51.1 91.98 700.00 54.2 RWE 92.19 700.21 I""', 54.2 RWS 92.23 700.25 57.1 92.39 700.41 59.8 92.73 700.75 -61.6 92.51 700.53 66.4 92.56 700.58 68.8 93.19 701.21 70.9 94.36 702.38 ~ 71.2 Bankfull 96.73 704.75 76.0 GB 97.75 705.77 76.0 RBHP 12 98.16 706.18 -Provisional mainstem Susitna River discharge recorded at Gold Creek on September 16, 1981 was 11,300 cfs (USGS 1981). EA-31 Table EA-28. Cross section elevations in transect 13 of Slough 168, -Surveyed on September 10, 1981. - Station Elevation True Elevation 0.0 LBHP 13 100.04 708.06 -0.0 GB 99.61 707.63 2.0 Bankfull 99.19 707.21 3.5 97.70 705.72 -5.5 96.72 704.74 7.5 95.37 703.39 13.5 93.87 701.89 16.0 LWE 93.22 701.24 ~' 16.0 LWS 20.0 92.96 700.98 22.5 RWE 22.5 RWS 93.22 701.24 26.0 93.92 701.94 35.0 93.84 701.86 45.0 93.55 701.57 -55.0 93.39 701.41 61.0 LWE 92.80 700.82 61.0 LWS '""'1 65.0 92.61 700.63 68.0 92.56 700.58 71.0 92.65 700.67 74.5 92.63 700.65 - 76.0 92.70 700.72 79.0 92.72 700.74 83.0 92.78 700.80 """'l 84.8 R~~E 92.87 700.89 84.8 RWS 87.5 93.83 701.85 """ 89.0 98.04 706.06 91.0 Bankfull 98.57 706.59 92.3 GB 98.33 706.35 92.3 RBHP 13 98.85 706.87 - Provisional mainstem Susitna River discharge recorded on September 10, 1981 at Gold Creek was 14,200 cfs (USGS 1981). - ---Data not collected. - - EA-32 - - - : - - .... ..... ,_ - - - - - Table EA-29. Cross section elevations in transect 14 of Slough 16B, surveyed September 10, 1981 Station Elevation True Elevation 0.0 LBHP 14 99.09 707.11 0.0 GB 98.68 706.70 2.9 Bankfull 97.87 705.89 3.4 LWE 93.58 701.60 3.4 LWS 93.74 701.76 6.5 93.40 701.42 8.1 93.17 701.19 12.7 92.83 700.85 16.4 92.74 700.76 21.0 93.06 701.08 28.5 93.17 701.19 35.0 93.67 701.69 40.5 93.60 701.62 44.6 93.67 701.69 45.8 RWE 93.76 701.78 45.8 RWS 93.74 701.76 52.5 93.75 701.77 59.5 93.86 701.88 65.4 93.92 701.94 68.2 93.88 701.90 70.4 93.75 701.77 73.4 94.67 702.69 76.2 Bankfull 97.79 705.81 78.1 GB 98.23 706.25 78.1 RBHP 14 98.58 706.60 Provisional mainstem Susitna River discharge recorded at Gold Creek in September 10, 1981 was 14,200 cfs (USGS 1981). EA-33 Table EA-30. Cross section elevations in transect 15 of Slough 168, -Surveyed on September 10, 1981. - Station Elevation True Elevation 0.0 LBHP 15 103.20 711.22 0.0 GB 102.82 710.84 2.8 Bankfull 103.22 711.24 4.9 99.52 707.54 7.5 97.95 705.97 9.7 97.06 705.08 14.3 95.93 703.95 18.3 94.90 702.92 23.0 94.05 702.07 27.0 LWS 93.69 701.71 27.0 LWE 93.76 701.78 32.0 93.45 701.47 39.0 93.14 701.16 49.0 92.80 700.82 54.0 92.74 700.76 61.0 93.22 701.24 66.1 RWS 97.70 705.72 66.1 RWE 93.76 701.78 """' 67.4 94.32 702.34 70.2 Bankfull 98.09 706.11 73.9 GB 98.42 . 706.44 73.9 RBHP 15 98.79 706.81 -· Provisional mainstem Susitna River discharge recorded at Gold Creek on September 10, 1981 was 14,200 cfs (USGS 1981). ~ - ~' EA-34 - - - Tab 1 e EA-31. Cross section elevations in transect 16 of Slough 168, surveyed September 10, 1981. Station Elevation True Elevation 0.0 LBHP 16 103.74 711.76 0.0 GB 103.19 711.21 2.7 103.11 711.13 6.4 Bankfull 97.14 705. 16 15.4 95.89 703.91 21.3 94.38 702.40 26.6 94.30 702.32 30.5 LWS 94.11 702.13 30.5 LWS 36.7 93.94 701.96 49.9 93.67 701.69 53.0 93.72 701.74 68.3 R~IE 93.85 701.87 68.3 RWS 93.92 701.94 72.0 94.45 702.47 76.1 95.75 703.77 76.7 Bankfull 98.11 706.13 77.6 98.48 706.50 82.2 GB 98.49 706.51 82.2 RBHP 16 98.89 706.91 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 10, 1981 was 14,200 cfs (USGS 1981). ---Data not collected. EA-35 Table EA-32. Cross section elevations in transect 17 (Head) of Slough 168 surveyed September 9, 1981. Transect was dewatered. Station Elevation True Elevation 0.0 LBHP 17 100.00 708.02 0.0 GB 99.61 707.63 2.0 99.50 707.52 6.0 98.50 705.52 8.0 96.15 704.17 20.0 95.14 703.16 60.0 95.00 703.02 84.0 95.02 703.04 114.0 95.15 703.17 130.0 95.48 703.50 142.0 95.95 703.97 155.0 96.00 704.02 174.0 96.47 704.49 182.5 96.42 704.44 185.0 96.15 704.17 187.0 96.71 704.73 189.0 97.21 705.23 189.5 97.88 705.90 191.0 99.63 707.65 194.5 GB 100.18 708.20 194.5 RBHP 17 100.65 708.67 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 9, 1981 was 14,500 cfs (USGS 1981). EA-36 - - - - - - Table EA-33. Head pin elevations in Slough 19, surveyed September 25, 1981. ,..., Bench l\1ark Elevation True Elevation TB~1 100.00 725.18 LBHP 1 (Nouth) 98.78 723.96 GB 98.42 723.60 RBHP 1 U1outh) 101.21 726.39 GB 99.75 724.93 LBHP 2 98.96 724.14 GB 98.54 723.72 -RBHP 2 100.19 725.37 GB 99.98 725.16 LBHP 3 99.66 724.84 P"' GB 99.25 724.43 RBHP 3 99.60 724.78 GB 99.20 724.38 LBHP 4 100.15 725.33 GB 99.77 724.95 RBHP 4 99.65 724.83 GB 99.36 724.54 -LBHP 5 99.41 724.59 GB 99.05 724.23 RBHP 5 100.26 . 725.44 GB 99.79 724.97 LBHP 6 99.81 724.99 GB 99.44 724.62 RBHP 6 100.47 725.65 ~ GB 100. 14 725.32 LBHP 7 100.00 725.18 GB 99.50 724.68 RBHP 7 101.21 726.39 '-GB 100.82 726.00 LBHP 8 100.06 725.24 GB 99.82 725.00 -RBHP 8 99.79 724.97 ' GB 99.35 724.53 LBHP 9 100.67 725.85 GB 100.23 725.41 fi""" RBHP 9 99.68 724.86 GB 99.21 724.39 LBHP 10 (Head) 100.14 725.32 ,.... GB 99.72 724.90 RBHP 10 (Head) 100.53 725.71 GB 100.05 725.23 R&~1 LRX 53 108.58 733.76 -r~a in stem RWS* 94.48 719.66 * The right bank mainstem Susitna River water surface elevation was -surveyed at a point adjacent to transect 1 on October 23, 1981. EA-37 ---------·-- Table EA-34. Cross section elevations in transect 1 (Mouth) of Slough 19~ surveyed September 26, 1981. - Station Elevation True Elevation 0.0 LBHP 1 98.78 723.96 - 0.0 GB 98.4-0 723.58 8.0 97.86 723.04 18.0 97.53 722.04 23.0 97.29 722.47 31.4 96.80 721.98 34.0 96.55 721.73 43.5 96.83 722.01 - 46.3 Bankfull 97.23 722.41 49.9 96.66 721.84 51.2 95.40 720.58 -53.4 94.95 720. 13 55.5 u~s 94.00 719.18 55.5 LWE 93.88 719.06 -56.0 93.74 718.92 56.5 93.68 718.86 57.1 93.61 718.79 57.5 93.73 718.91 -57.8 R~/S 93.92 719.18 57.8 RWE 94.63 719.10 59.1 94.63 791.81 -52.2 94.98 720.16 64.8 96.27 721.45 71.4 96.81 721.99 74.3 97.53 722.71 80.8 96.33 721.51 97.1 Bankfu11 97.04 722.22 101.5 98.97 724.15 -106.6 99.73 724.91 106.6 RBHP 1 100.20 725.38 Provisional mainstem Susitna River discharge recorded at Gold Creek on - September 26, 1981 was 9,560 cfs (USGS 1981). - - .... EA-38 1""' - - - I""' Table EA-35. Cross section elevations in transect 2 of Slough 19, surveyed September 26, 1981. Station Elevation True Elevation 0.0 LBHP 2 98.95 724.13 0.0 GB 98.53 723.71 2.0 Bankfull 98.61 723.79 4.1 96.98 722.16 9.2 96.24 721.42 16.5 95.26 720.44 23.6 94.37 719.55 34.0 LWS 94.05 719.23 34.0 LWE 93.90 719.08 36.0 93.72 718.90 38.0 93.89 719.07 40.7 93.68 718.86 42.6 93.59 718.77 48.2 93.75 718.93 65.4 R~JS 94.06 719.24 65.4 RHE 93.80 718.98 62.6 94.61 719.79 71.5 94.50 719.68 78.9 95.18 720.36 87.0 96.42 721.60 99.7 96.70 721.88 102.9 98.11 723.29 111.5 98.66 723.84 113.1 Bankfull 99.88 725.06 115.3 GB 100.19 725.37 115.3 RBHP 2 100.01 725.19 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 26, 1981 was 9,560 cfs (USGS 1981). EA-39 Table EA-36. Cross section elevations in transect 3 of Slough 19, ~ surveyed September 26, 1981. ~ Station Elevation True Elevation 0.0 LBHP 3 99.66 724.84 ~ 0.0 GB 99.25 724.43 2.8 Bankfull 98.68 723.86 5.1 97.60 722.78 -7.4 97.24 722.42 9.1 95.99 721.17 20.4 94.92 720.10 27.5 u~s 94.08 719.26 - 27.5 LWE 93.88 719.06 32.0 93.55 718.73 35.0 93.40 718.58 ~ 51.8 93.93 719.11 56.6 93.53 718.71 61.7 RWS 94.08 719.26 61.7 RWE 93.97 719.15 74.4 95.02 720.20 92.9 96.76 721.94 95.5 97.87 723.05 102.4 Bankfull 98.94 724.12 104.6 GB 99.20 724.38 104.6 RBHP 3 99.60 724.78 .... Provisional mainstem Susitna River discharge recorded at Gold Creek on September 26, 1981 was 9,560 cfs (USGS 1981). ·- - EA-40 - ,_ - - Table EA-37. Cross section elevations in transect 4 of Slough 19, surveyed September 26, 1981. Station Elevation True Elevation 0.0 LBHP 4 100.16 725.34 0.0 GB 99.79 724.97 2.3 Bankfull 99.21 724.39 9.6 97.77 722.95 11.0 97.69 722.87 16.4 95.56 720.74 21.0 94.62 719.80 23.2 L\>JS 94.34 719.52 23.2 LWE 94.20 719.38 27.6 93.79 718.97 31.2 93.63 718.81 37.8 93.81 718.99 41.9 RWS 94.35 719.53 41.9 RWE 94.26 719.44 47.5 94.84 720.02 52.6 96.71 721.89 54.7 Bankfull 98.83 724.01 57.2GB 99.38 724.56 57.2 RBHP 4 99.66 724.84 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 26, 1981 was 9,560 cfs (USGS 1981). EA-41 Table EA-38. Cross section elevations in transect 5 of Slough 19, surveyed September 26, 1981 Station Elevation True Elevation 0.0 LBHP 5 99.41 724.59 0.0 GB 99.09 724.27 2.2 Bankfull 98.95 724.13 3.0 97.50 722.68 7.5 96.62 721.80 10.1 95.73 720.91 10.6 95.15 720.33 11.6 LWS 94.97 720.15 11.6 U~E 94.91 720.09 13.9 94.60 719.78 15.2 94.46 719.64 18.1 94.43 719.61 19.2 94.79 719.97 22.2 RWS 94.98 720.16 22.2 R1~E 94.87 720.05 27.4 Dewatered 95.17 720.35 31.0 Dewatered 95.67 720.85 31.8 DevJatered 96.38 721.56 33.7 Dewatered 96.35 721.53 34.9 Dewatered 95.59 720.77 35.3 LWS 94.97 720.15 35.5 LWE 94.83 710.01 38.2 94.40 719.58 41.5 RWS 94.98 720.16 41.5 RWE 94.86 720.04 43.7 96.56 721.74 53.0 97.33 722.51 65.0 98.29 723.47 70.3 GB 70.3 RBHP 5 100.25 725.43 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 26, 1981 was 9,560 cfs (USGS 1981). ---Data not collected. EA-42 - ~ ~ - - - ~ ~ -~ - - - Table EA-39. Cross section e1evations in transect 6 of Slough 19, surveyed September 26, 1981. - Station Elevation True Elevation 0.0 LBHP 6 99.81 724.99 0.0 GB 99.47 724.65 4.4 Bankfull 98.67 723.85 .-7.9 97.50 722.68 11.2 96.75 721.93 16.0 96.52 721.70 17.9 96.11 721.29 18.5 LWS 95.68 720.86 18.5 LWE 95.57 720.75 20.7 95.42 720.60 22.6 95.14 720.32 24.9 95.22 720.40 27.8 RWS 95.62 720.80 27.8 RWE \~ 30.5 96.61 721.79 31.7 Bankfull 98.99 724.17 40.4 GB 100. 18 725.36 -40.4 RBHP 6 100.47 725.65 Provisional mainstem Susitna River discharge recorded at Gold Creek on -September 26, 1981 was 9,560 cfs (USGS 1981). ---Data not collected EA-43 ..... Table EA-40. Cross section elevations in transect 7 of Slough 19, surveyed September 26, 1981. Station Elevation True Elevation 0.0 LBHP 7 100.00 725.18 0.0 GB 99.59 724.77 1. 9 Bankfull 99.07 724.25 6.8 97.67 722.85 10.4 96.44 721.62 17.8 LWS 96.07 721.25 17.8 U~E 95.97 721.15 21.2 Oewatered 96.13 721.31 19.3 Oewatered 96.10 721.28 26.3 Dewatered 95.95 721.13 28.6 RWS 96.12 721.30 28.6 RWE 95.98 721.16 30.3 96.59 721.77 31.4 98.23 723.41 33.4 Bankfull 100.28 725.46 36.0 GB 100.86 726.04 36.0 RBHP 7 101.21 726.39 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 26, 1981 was 9,560 cfs (USGS 1981). EA-44 .... - ~. - - - ·- - - """"' - - Tab 1 e EA-41. Cross section elevations in transect 8 of Slough 19, surveyed September 26, 1981. Cross section was dewatered. Station Elevation True Elevation 0.0 LBHP 8 100.06 725.24 0.0 GB 99.83 725.01 2.2 Bankfull 99.68 724.86 5.4 98.62 723.80 8.7 97.62 722.80 13.3 97.27 722.45 17.7 97.58 722.76 20.1 97.40 722.58 22.2 96.94 722.12 23.8 96.83 722.01 25.7 98.18 723.36 30.0 Bankfull 99.34 724.52 35.2 GB 99.36 724.54 35.2 RBHP 8 99.79 724.97 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 26, 1981 was 9,560 cfs (USGS 1981). EA-45 Table EA-42. Cross section elevations in transect 9 of Slough 19, surveyed September 26, 1981. Station 0.0 LBHP 9 0.0 GB 2.4 Bankfull 2.8 5.2 5.7 9.1 10.1 LWS 10.1 LWE 13.5 15.6 R~!S 15.6 R~JE 18.7 22.0 23.7 Bankfull 26.6 GB 26.6 RBHP 9 Elevation 100.67 100.24 100.10 98.85 98.37 97.74 97.14 96.86 96.74 96.70 96.82 96.76 96.92 97.40 98.92 99.21 99.68 True Elevation 725.85 725.42 725.28 724.03 723.55 722.92 722.32 722.04 721.92 721.88 722.00 721.94 722.10 722.58 724.10 724.39 724.86 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 26, 1981 was 9,560 cfs (USGS 1981). EA-46 ~- - ~I - - - - - - - Table EA-43. Cross section elevations in transet 10 (Head) of Slough 19, surveyed September 26, 1981. Station 0.0 LHBP 10 0.0 GB 3.4 Bankfull 4.5 5.7 LWS 5. 7 L\~E 9. 6 R~~s 9. 6 RWE 16.5 12.2 13.5 Bankfull 16.1 GB 16.1 RBHP 10 Elevation 100.14 99.76 98.64 97.12 96.80 96.78 96.80 96.77 97.15 98.42 98.64 99.98 100.54 . True Elevation 725.32 725.94 723.82 722.30 721.98 721.96 748.98 721.95 722.33 723.60 723.82 725.16 725.72 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 26, 1981 was 9,560 cfs (USGS 1981). EA-47 Table EA-44. Head pin elevations in Slough 21 surveyed August 24-27, - 1981. - Bench ~1ark Elevation True Elevation LBHP 1 (Head) 100.12 759.42 - GB 99.49 758.79 RBHP 1 (Head) 97.33 756.63 GB 96.71 756.01 -LBHP 2 96.61 755.91 GB 96.20 755.50 RBHP 2 97.02 756.32 -GB 96.41 755.71 LBHP 1-A 98.00 757.30 GB 97.54 756.84 RBHP 1-A 101.17 760.47 -GB 100.64 759.94 LBHP 1-B 100.85 760.15 GB 100.30 759.60 RBHP 1-B 99.73 759.03 GB 99.34 758.64 LBHP 3 96.71 756.01 GB 96.25 755.55 RBHP 3 96.64 755.94 GB 96.09 755.39 LBHP 4 93.94 753.24 ~. GB 93.49 752.79 RBHP 4 95.44 754.74 GB 94.87 754.17 LBHP 5 93.20 752.50 GB 92.92 752.22 RBHP 5 92.58 751.88 GB 92.15 751.45 HP 5-A 93.67 752.97 GB 93.12 752.42 LBHP 6 92.90 752.20 GB 92.42 751.72 """' RBHP 6 92.56 751.86 GB 92.13 751.43 LBHP 7 93.47 752.77 ~ GB 93.04 752.34 RBHP 7 93.36 752.66 GB 92.77 752.07 LBHP 8 93.00 752.30 - GB 92.57 751.87 RBHP 8 91.44 750.74 GB 90.92 750.22 LBHP 9 93.03 752.33 GB 92.62 751.92 RBHP 9 92.35 751.65 GB 91.93 751.23 """' J!l"l"; EA-48 !!""\ Table EA-44. (Continued) Bench Mark Elevation True Elevation LBHP 10 93.23 752.53 """ GB 92.73 752.03 RBHP 10 92.27 751.57 GB 91.94 751.24 LBHP 11 91.68 750.98 GB 91.23 750.53 RBHP 11 92.08 751.38 GB 91.56 750.86 LBHP 12 91.94 751.24 GB 91.59 750.89 RBHP 12 92.30 751.60 GB 91.83 751.13 LBHP 13 (r1outh) 91.14 750.44 GB 90.77 750.07· RBHP 13 ( t·1outh) 92.08 751.38 GB 91.67 750.97 r1ainstem R\~S* 92.92 752.23 Mainstem RWS** 92.12 751.42 -R&r1 LRX 56 100.00 759.30 * The mainstem water surface elevation was surveyed on September 27, 1981, 227 ft from the left bank head pin 13 at 282° from magnetic north. r""! ** The mainstem water surface elevation was surveyed on October 23, 1981, 75 ft from the left bank head pin 13 at 290° from magnetic north. EA-49 Table EA-45. Cross section elevations in transect 1 (Head) of Slough 21, surveyed September 5, 1981. Transect was dewatered. Station Elevation True Elevation 0.0 LBHP 1 100.12 759.42 0.0 GB 99.52 758.82 22.0 98.88 758.18 34.0 92.22 756.52 40.0 96.56 755.86 50.0 95.02 754.32 61.5 94.51 753.81 69.0 95.23 754.53 75.5 95.00 754.30 79.0 94.42 753.72 81.9 94.75 754.05 96.0 94.71 754.01 105.0 95.73 755.03 123.0 96.40 755.70 135.6 96.55 755.85 139.3 95.94 755.24 155.8 96.68 755.98 159.1 GB 96.76 756.06 159.1 RBHP 1 97.37 756.67 Provisional mainstem discharge Susitna River recorded at Gold Creek on September 5, 1981 was 16,000 cfs (USGS 1981). EA-50 - '~ """ flli9lif1 ~ .... .... """" - - - - .... - - - Table EA-46. Cross section elevations in transect 1-A (Head) of Slough 21, surveyed September 5, 1981. · Transect was dewatered. Station Elevation True Elevation 0.0 LBHP 1-A 98.00 757.30 ~ 0.0 GB 97.58 756.88 5.0 97.49 756.79 12.0 97.12 756.42 20.5 96.67 755.97 26.6 96.51 755.81 29.5 96.05 755.35 34.5 97.50 756.80 39.0 98.60 757.90 50.0 99.60 758.90 57.6GB 100.64 759.94 57.6 RBHP 1-A 101.17 760.47 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 5, 1981 was 16,000 cfs (USGS 1981). EA-51 Table EA-47. Cross section elevation in transect 1-B of Slough 21, surveyed September 5, 1981. Transect was dewatered. Station 0.0 LBHP 1-B 0.0 GB 1.5 6.0 16.5 19.4 22.0 24.0 33.0 38.0 40.5 43.0 46.5 48.5 52.5 57.5 66.1 70.2 78.3 GB 78.3 RBHP 1-B Elevation 100.85 100.26 99.07 98.09 97.69 98.00 97.28 97.76 97.19 97.53 97.22 97.55 96.76 97.14 96.69 96.20 96.37 98.24 99.36 99.74 True Elevation 760.15 759.59 758.37 757.39 756.99 757.30 756.58 757.06 756.49 756.83 756.52 756.85 756.06 756.44 755.99 755.50 755.67 757.54 758.66 759.04 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 5, 1981 was 16,000 cfs (USGS 1981). EA-52 - - ~ ! - - - -· - ~ - - Table EA-48. Cross section elevations in transect 2 of Slough 21. surveyed Septembers. 1981. Transect was dewaterd. Station Elevation True Elevation 0.0 LBHP 2 96.66 755.96 0.0 GB 96.25 755.55 3.0 96.04 755.34 13.0 95.15 754.45 16.0 94.30 753.60 17.3 93.59 752.89 21.0 92.95 752.25 44.0 92.82 752.12 59.5 93.09 752.39 78.5 93.77 753.07 95.2 94.55 753.85 103.0 95.42 754.72 109.7 GB 95.47 754.77 109.7 RBHP 2 96.08 755.38 Provisional mainstem Susitna River discharae recorded at Gold Creek on September 5, 1981 was 16.000 cfs (USGS 198l). EA-53 Table EA-49. Cross section elevations in transect 2-A of Slough 21, surveyed September 5, 1981. Station Elevation True Elevation 0. 0 LBHP 2 -A 97.00 756.30 0.0 GB 96.41 755.71 1.0 96.47 755.77 5.0 95.84 755.14 7.0 95.34 754.64 12.0 96.13 755.43 17.0 95.89 755.19 21.0 94.47 753.77 23.0 LWS 23.0 LWE 93.63 752.93 25.5 93.29 752.59 28.5 93.08 752.39 32.9 RWS 32.9 RWE 93.54 752.84 41.0 93.69 752.99 43.8 94.35 753.65 46.0 95.12 754.42 54.0 96.57 755.87 63.7 97.53 756.83 63.7 RBHP 2-A 98.04 757.34 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 5, 1981 was 16,000 cfs (USGS 1981). ---Data not collected EA-54 - .... - - - - - - - -' -I - , .... ~ - - - Table EA-50. Cross section elevations in transect 3 of Slough 21, surveyed September 5, 1981 Station Elevation True Elevation 0.0 LBHP 3 96.71 756.01 0.0 GB 96.26 755.56 5.5 95.54 754.84 12.0 94.50 753.80 29.0 93.64 752.94 36.0 93.92 753.22 46.0 93.32 752.62 51.0 92.92 752.22 56.7 92.49 751.79 68.5 91.49 750.79 80.0 LWS 80.0 LHE 90.82 750.12 83.0 90.48 749.78 91.2 89.66 748.96 95.1 89.09 748.39 100.5 88.99 748.29 107.2 RWS 107.2 R~.JE 90.82 750.12 110.0 91.99 751.29 113.5 95.85 755.15 115.5 GB 96.07 755.37 115.5 RBHP 3 96.65 755.95 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 5, 1981 was 16,000 cfs {USGS 1981). ---Data not collected EA-55 Tab 1 e EA-51. Cross section e1evations in transect 4 of Slough 21, surveyed September 5, 1981. Station Elevation True Elevation 0.0 LBHP 4 93.94 753.24 0.0 GB 93.49 752.79 3.0 93.54 752.84 9.0 93.08 752.38 12.2 92.23 751.53 16.0 91.54 750.84 25.0 On top of rocks 91.78 751.08 25.0 On the substrate 90.92 750.22 29.8 LWS 29.8 LWE 90.65 749.95 34.5 90.40 749.70 40.6 Dry 90.70 750.00 46.0 90.64 749.94 48.8 90.37 749.67 51.0 90.47 749.77 53.3 RWS 53.3 RWE 90.73 750.03 62.0 91.18 750.48 73.5 91.66 750.96 84.0 93.08 752.38 95.6 94.66 753.96 96.7 GB 94.84 754 .14 96.7 RBHP 4 95.44 754.74 Provisional mainstem Susitna River discharge recorded at Gold Creek on September 5, 1981 was 16,000 cfs (USGS 1981). ---Data not collected. EA-56 - - ..., - !""" - """! ~ - - - - - ·- - - f""' ..... - Table EA-52. Cross section elevations in transect 5 of Slough 21, surveyed August 25, 1981. Station Elevation True Elevation 0.0 LBHP 5 93.20 752.50 0.0 GB 92.92 752.22 4.0 92.61 751.91 5.0 91.77 751.07 7.5 90.51 749.81 10.0 89.77 749.07 13.3 u~s 13.3 LWE 89.04 748.34 19.0 88.54 747.84 21.9 88.45 747.75 26.3 88.77 748.07 29.4 88.91 748.21 31.0 Dry 89.06 748.36 36.0 88.81 748.11 38.0 88.70 748.00 42.0 88.90 748.20 45.6 88.84 748.14 51.4 RWS 51.4 RHE 88.97 748.27 56.0 89.94 749.24 61.0 90.88 750.18 66.7 91.47 750.77 68.7 97.77 757.07 70.7 91.36 750.66 75.0 91.47 750.77 78.2 GB 92.13 751.43 78.2 RBHP 5 92.57 751.87 Provisional mainstem Susitna River discharge recorded at Gold Creek on August 25, 1981 was 28,600 cfs (USGS 1981). ---Data not collected. EA-57 Tab 1 e EJ\-53. Cross section elevations in transect 5-A of Slough 21, surveyed August 25, 1981. Station 0.0 LBHP 5-A 0.0 GB 3.0 6.0 8.0 14.4 19.0 23.5 27.0 32.4 LWS 32.4 LWE 36.0 39.0 41.2 43.9 R~JS 43.9 RWE 45.4 47.0 49.5 51.8 GB 51.8 RBHP 5-A Elevation 92.58 92.14 91.94 91.54 90.98 91.09 90.34 90.45 89.04 88.32 87.12 86.85 87.29 88.33 90.93 91.77 92.81 93.16 93.68 True Elevation 751.88 751.44 751.24 750.84 750.28 750.39 749.64 749.75 748.34 747.62 746.42 7 46.15 . 746.59 747.63 750.23 751.07 752.11 752.46 752.98 Provisional mainstem Susitna River discharge recorded at Gold Creek on August 25, 1981 was 28,600 cfs (USGS 1981). ---Data not collected. EA-58 - - - - - - - r - - - Table EA-54. Cross section elevations in transect 6 of Slough 21, surveyed August 25~ 1981. Station 0.0 LBHP 6 0.0 GB 7.0 12.0 20.0 29.0 36.0 46.0 56.0 64.0 69.0 LWS 69.0 U~E 73.0 76.0 79.0 83.0 lg. pile of rocks 86.0 90.0 92.3 R\tiS 92.3 RWE 95.5 98.0 99.0 100.2 GB 100.2 RBHP 6 Elevation 92.90 92.10 92.03 91.69 90.73 89.95 89.18 89.34 89.18 88.44 88.18 87.84 87.88 87.78 87.76 87.83 87.92 88.13 87.84 90.19 91.18 91.92 92.18 92.55 True Elevations 752.20 751.40 751.33 750.99 750.03 749.25 748.48 748.64 748.48 747.74 747.48 747.14 747.18 747.08 747.06 747.13 747.22 747.43 747.14 749.49 750.48 751.22 751.48 751.85 Provisional mainstem Susitna River discharge recorded at Gold Creek on August 25, 1981 was 28,600 cfs (USGS 1981). ---Data not collected. EA-59 Table EA-55. Cross section elevations in transect 7 of Slough 21, ... surveyed August 25, 1981. - Station Elevation True Elevation 0.0 LBHP 7 93.47 752.77 0.0 GB 93.04 752.34 5.0 92.54 751.84 8.0 91.39 750.69 ~ 14.0 88.48 747.78 16.0 88.37 747.67 17.5 88.49 747.79 22.2 90.05 749.35 27.0 90.83 750.13 35.0 91.11 750.41 54.5 90.45 749.75 ~ 62.0 90.44 749.74 75.0 89.65 748.95 89.6 LWS -89.6 LWE 87.77 747.07 94.0 87.17 746.47 98.5 87.02 746.32 103.0 87.02 746.32 -104.0 87.13 746.43 105.0 87.11 746.41 107.0 87.23 746.53 109.5 87.09 746.39 114.3 RWS 114.3 R\~E 87.73 747.03 119.0 89.35 748.65 -119.7 91.98 751.28 124.5 95.52 754.82 126.1 GB 92.78 752.08 126.1 RBHP 7 93.37 752.67 Provisional mainstem Susitna River discharge recorded at Gold Creek on August 25, 1981 was 28,600 cfs (USGS 1981). ---Data not collected. - - E.ll.-60 """ - - - - - Table EA-56. Cross section e1evations in transect 8 of Slough 21, surveyed August 25, 1981. Station Elevation True Elevation 0.0 LBHP 8 93.00 752.30 0.0 GB 92.57 751.87 5.5 91.66 750.96 7.0 90.21 749.51 12.5 88.42 747.72 26.0 87.77 747.07 30.0* 87.19 746.49 39.3 LWS 39.3 LWE 86.86 746.16 43.0 86.60 745.90 49.0 86.23 745.53 55.0 86.44 745.74 59.5 86.45 745.75 66.5 86.39 745.69 72.5 86.28 745.58 79.4 Rl.~S 79.4 RWE 86.86 746.16 81.5 87.35 746.65 83.0 90.38 749.68 86.4 GB 90.92 750.22 86.4 RBHP 8 91.45 750.75 Provisional mainstem Susitna River discharge recorded at Gold Creek on August 25, 1981 was 28,600 cfs (USGS 1981). * Intragravel water was observed at this location. ---Data not collected. EA-61 Table EA-57. Cross section elevations in transect 9 of Slough 21, surveyed August 25, 1981. • - Station Elevation True Elevation 0.0 LBHP "9 93.03 752.33 )'!'!!! 0.0 GB 92.60 751.90 5.0 91.96 751.26 7.0 89.72 749.02 ~ 11.0 89.67 748.97 17.0 89.40 748.70 28.0 86.59 745.89 40.1 LWS 40.1 LWE 86.07 745.37 47.0 85.91 745.21 56.0 85.78 745.08 65.0 Dry 86.07 745.37 72.5 Dry 85.99 745.29 78.0 85.65 744.95 ~ 84.0 85.51 744.81 87.0 85.64 744.94 89.0 85.66 744.96 92.6 RWS .... 92.6 R\~E 85.91 745.21 95.1 85.99 745.29 98.0 87.74 747.04 """" 102.5 91.92 751.22 105.4 GB 91.93 751.23 105.4 RBHP 9 92.36 751.66 ~ Provisional mainstem Susitna River discharge recorded at Gold Creek on August 25, 1981 was 28,600 cfs (USGS 1981). ----Data not collected. - - - - EA-62 Table EA-58. Cross section elevations in transect 10 of Slough 21, surveyed August 25, 1981. - Station Elevation True Elevation 0.0 LBHP 10 93.23 752.53 0.0 GB 92.72 752.02 6.0 90.36 749.66 11.0 88.66 747.96 15.0 88.45 747.75 20.0 86.54 745.84 22.6 LWS ( Sma 11 Channe 1 ) 22.6 U~E 86.38 745.68 {Small Channe 1 ) 25.7 RWS {Small Channe 1 ) 25.7 RWE 86.37 745.67 {Small Channel) 35.0 86.64 745.94 60.0 86.40 745.70 82.4 LWS 82.4 LWE 85.58 744.88 95.0 85.06 744.36 97.0 84.81 744.11 98.0 85.09 744.39 99.4 84.88 744.18 105.8 RWS 105.8 R~IE 85.60 744.90 109.0 86.34 745.64 113.5 91.81 751.11 116.1 GB 91.94 751.24 116.1 RBHP 10 92.28 751.58 Provisional mainstem Susitna River discharge recorded at Gold Creek on August 25, 1981 was 28,600 cfs {USGS 1981). ---Data not collected - - EA-63 Table EA-59. Cross section elevations in transect 11 of Slough 21, surveyed August 25, 1981. Station Elevation True Elevation · 0. 0 LBHP 11 91.68 750.98 0.0 GB 91.25 750.55 3.0 90.99 750.29 4.0 89.74 749.04 5.5 89.28 748.58 7.5 89.55 748.85 15.0 88.26 747.56 17.5 87.19 746.49 19.1 LWS 19. 1 UlE 85.89 745.19 21.0 85.76 745.06 24.5 RWS 24.5 RWE 85.88 745.18 28.4 85.95 745.25 32.0 87.82 747.12 36.0 88.59 747.89 38.9 88.38 747.68 40.6 85.69 744.99 42.5 LWS 42.5 LWE 85.58 744.88 Staff gage 87.75 747.05 43.5 84.55 743.85 47.0 84.79 744.09 51.0 86.02 745.32 53.0 85.26 744.56 64.0 85.23 744.53 73.0 85.13 744.45 79.0 85.25 744.55 93.0 85.59 744.89 100.0 85.47 744.77 104.3 R~~s 104.3 RWE 85.55 744.85 108.0 90.18 749.48 111.0 91.41 750.71 112.2 GB 91.64 750.94 112.2 RBHP 11 92.08 751.38 Provisional mainstem Susitna River discharge recorded at Gold Creek on August 25, 1981 was 28,600 cfs (USGS 1981). ---Data not collected. EA-64 """ - ""'"' - - - .... - - .... F" - - r Table EJl.-60. Cross section e~evations in transect 12 of Slough 21, surveyed August 25, 1981. Station Elevation True Elevation 0.0 LBHP 12 91.94 751.24 0.0 GB 91.60 750.90 3.0 91.26 750.56 6.5 88.42 747.72 17.0 89.27 748.57 11.5 88.06 747.36 27.5 88.88 748.18 32.5 88.14 747.44 40.0 88.82 748.12 43.5 88.36 747.66 47.0 LWS 47.0 LWE 85.40 744.70 49.5 84.14 743.44 54.5 84.46 743.76 72.0 84.70 744.00 79.0 84.87 744.17 92.0 84.60 743.90 103.5 84.74 744.04 108.6 RWS 108.6 RWE 85.43 744.73 115.0 91.42 750.72 117.4 GB 91.85 751.15 117.4RBHP 12 92.22 751.52 Provisional mainstem Susitna River discharge recorded at Gold Creek on August 25, 1981 was 28,600 cfs (USGS 1981). ---Data not collected. EA-65 Tab 1 e EA-61. Cross section elevations in transect 13 of Slough 21, surveyed August 25, 1981. Station Elevation True Elevation 0.0 LBHP 13 91.15 750.45 0.0 GB 90.78 750.08 2.0 90.74 750.04 7.0 86.72 746.02 13.5 85.77 745.07 20.0 86.42 745.75 42.0 85.78 745.08 66.0 86.21 745.51 82.0 86.41 745.71 86.2 LWS 86.2 LWE 85.43 744.73 94.0 83.85 743.15 108.5 84.14 743.44 120.0 84.80 744.10 127.5 84.18 743.48 134.5 84.97 744.27 134.7 RWS 134.7 RWE 85.43 744.73 138.0 91.47 750.77 141.5 GB 91.66 750.96 141.5 RBHP 13 92.00 751.30 Provisional mainstem Susitna River discharge August 25, 1981 was 28,600 cfs (USGS 1981). recorded at Gold Creek on ---Data not collected. EA-66 ~ ~ I""' ~ ~~ - """ """! ""1 - -