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HomeMy WebLinkAboutKing Cove Hydroelectric Project Feasibility Study Delta Creek Relative to Aquatic 1983. i I I ' ' 1-\ c::) 834 W. 5th Ave~ f·.nci'lorage, Alaska 99501 . KING COVE HYDROELECTRIC PROJECT FEASIBILITY STUDY j.ol LIB RY_COP.Y ~~ ·;,-~-'"~ v: /r- .. / ~) A REPORT ON CONTINUED FIELD INVESTIGATIONS OF :~ ~ DELTA CREEK RELATIVE TO AQUATIC BIOLOGY AND HYDROLOGY Prepared for: JAN 1 a 1983 t.LASKA POWER AUTHORI.n ALASKA POWER AUTHORITY Prepared by : DO'WL ENGINEERS <: I ) I ·\>f-~ . (S -~ January 1983 ~ ~p ""' -· .. '----__ ALASKA POWER A"l,.THO:R . .::J_J2 I iJ Ale Code I_,.,-' J. Date:~~ .. ~ Mr. Donald W. Baxter ALASKA POWER AUTHORITY 334 West 5th Avenue Anchorage, Alaska 99501 January 18, 1983 W.O. #D13470 Subject: Feasibi I ity Study for King Cove Hydroelectric Project: Supplemental Fisheries and Hydrology Data Dear Mr. Baxter: As you requested, the attached document "A report on continued field observations of Delta Creek relative to aquatic biology and hydro I ogyu high I i ghts the resu Its of DOWL • s addition a I fie I d work to date at De Ita· Creek near King Cove, A I ask a. This brief report for distribution to the appropriate resource agencies responds to agency comments received on the project during a interagency meeting with the Alaska Power Authority, U.S. Fish & Wildlife Service and Alaska Department of Fish & Game on Apri I 28, 1982. The report is not a complete revision of Appendix E (Environ- mental Report) of the Feasibi I ity Study but it does incorpor- ate portions of the original text and figures to facilitate its use by the reader. 1 n addition to providing a record of the observations on anadromous species, this report also up- dates some of the previously supplied hydrologic data. The monitoring of the flow in Delta Creek is, of course, an on- going program and three additional site visits are planned for 1983. 1 am prepared to respond to any additional comments or input received by your office on those provided directly to DOWL. If you have any additional need for information or assistance at this time, please do not hesitate to cal I. RD:tfl4g Enclosure Sincerely, DOWL ENGINEERS Ronald R. Dagon, Director Environmental Services KING COVE HYDROELECTRIC PROJECT FEASIBILITY STUDY A REPORT ON CONTINUED FIELD INVESTIGATIONS OF DELTA CREEK RELATIVE TO AQUATIC BIOLOGY AND HYDROLOGY Prepared for: ALASKA POWER AUTHORITY Prepared by: DOWL ENGINEERS January 1983 tr'! aJ ~~ ~. --.~- "' ;~~: lJ ! ~ TABLE OF CONTENTS ·,...~-' ~~, PROJECT OESCRIPTIONi .•................................. .: S ~~ ~ SCOPE OF WORt(\ ......................................... . ·~~ _,.- YOROLOGY ....................................... • ...... . r ,t . L£ Spawning & Rearing ................................ . CURRENT UTILIZATION OF FISH~RY RESOURCES .............. . HYS~ STREAM DESCRIPTION ........................... . sect i on 1 ......................................... . Section 2 ......................................... . -Section 3 .......•.............................. · .. · (FiSHERY IMPACTS ....................................... . PUBLIC REVIEW NOMINATION FOR WATERS IMPORTANT TO ANAO- ROMOUS SPECIES ......... ~ ............................ . REFERENCES •.............. "~ ............................ . ,...,. '. LIST OF FIGURES •- ·Page 1 1 3 9 10 15 16 16 18 20 20 21 21 Page Figure 1 Project Location Map .............. ... .. . . . .... 2 I . 2 Schematic Diagram of Delta Creek System .. ..... 5 -- • .,.... ._,-... -·~A A•--~-• >;:':""-- Tables 1 2 LIST OF TABLES Water Quality Data, 1981/82, Delta Creek ...... . Discharge Data, 1981/82, Delta Creek 3 Delta Creek Estimated Total Pink and 8 9 Chum Salmon Escapements ....................... 11 Species and Numbers of Fish Caught in Delta Creek ................................ 12 5 DOWL Stream Counts, 1982 LIST OF PHOTOGRAPHS Photographs 1 Upper Delta Creek 2 3 4 5 6 Looking Downstream at Proposed Dam Site ...... . Delta Creek, Looking Upstream ................ . Typical Side Channel in Lower Delta Creek Clear Tributary Glacial Tributary I I 14 4 4 17 17 19 19 A REPORT ON CONTINUED FIELD INVEST I GAT I ON OF DELTA CREEK RELATIVE TO AQUATIC BIOLOGY AND HYDROLOGY PROJECT DESCRIPTION small diversion weir will be constructed across Delta , ~Creek, at the 400 foot e I evat ion I eve I . Water w i I I be diverted • into a penstock, which wi II lead to the powerhouse located near the airstrip . The power capacity wi II be 575 kilowatts. A road wi II be constructed from the airstrip to the powerhouse, and on up to the diversion weir. A transmission I ine wil I lead from the powerhouse to King Cove . A project I ocat ion map is provided in Figure 1 . ~d· {)l\1 (L..~ SCOPE OF WORK o.J ~) ~ ~t' ... II ( ~ As 1 n 1 t 1 a y contracte environmental studies were to include an initial two-day re- connaissance visit, fo I I owed by a three-to four-day trip for more deta i I ed studies. Literature review and discussion with I oca I residents and agency members were to be combined with field studies to obtain information on fish and wildlife re- sources in the area and effects of the project on these re- sources. Hydrology, land status, archaeologic and/or historic sites, and permitting requirements were to be briefly dis- cussed, as wei I as impacts on recreational values, air quality, socioeconomics and scenic viewpoints . s The in it i a I reconnaissance A s i te visit occurred on Sep- tember 17-18, 1981, and a more detailed site investigation took place October 12-16, 1981. Delta Creek was walked from the - 1 - Cold Bay Deer Passage Deer-Island SCALE 1:250000 0 I ~ PROJECT LOCATION MAP I EXPLANATI-ON .,... Propoaed Dam Site -Stream Reach Dlvlalona Water Quality Sampling Site ••••• Propoaed Trana. Route Cape J 'I' 'fi. t ....: ! ~ FIGURE 1 airstrip to above the dam site with minnow traps selectively placed throughout its length . Photos 1 and 2 show upper Delta Creek and the proposed dam site . Numbers and I ocat ions of wildlife and wildlife sign were noted . Local residents were contacted through a community meeting on September 16, 1981, and through discussions with individuals during both visits . The A I aska Power Authority he I d an i nformat i ona I meeting to discuss four potential hydropower sites, including King Cove, with interested federal, state and local organizations in Anchorage on October 21, 1981 . Additional contacts were made by DOWL with state and federal agencies on an individual basis during September, October and November of the same year. In 1982 following an interagency meeting with DOWL, Alaska Power Authority, u.s. Fish S Wi ldlife Service and Alaska Department of Fish and Game on Apri I 28, the scope of work was amended to include two additional trips to King Cove in August and October of 1982 . This report incorporates the results of these further f i eld investigations at Delta Creek during the fal I of 1982 as wei I as updating some of the previous supplied data on project stream flows . The most recent site visit took place on January 8, 1983 . HYDROLOGY Delta Creek originates on the slopes of Mount Dutton and drains an area of approximately 14.0 square miles at Lenard Harbor where it discharges . Two add1tional major tributaries join the main stem of Delta Creek below the proposed diversion weir I ocat ion and together constitute a drainage area of -o--:-Q') l'i . ~' "! square m i I es. (71 percent of tota I a i nage area .) The north tributary (see 1gure 2) flows into" Delta Creek two miles up- stream from Lenard Harbor. This tributary heads in the same -3 - 7 ,_ No. 1 Upper Delta Creek No. 2 Looking downstream at proposed darn site. • MOUNT DUTTON Uorth Tributary estimated mean annual flow : 18ft 3/sec . Delta Creek estimated mean annual flow : 90ft 3/sec . > a: ~ .. ::» • ~ t- % t- ~ 0 z KING COVE t ~ENGINEERS SCHEMATIC DIAGRAM of DELTA CREEK SYSTEM Upper Delta Cr. estimated mean annual flow: 24ft 3 /sec. PROPOSED POWERHOUSE AIRSTRIP CREEK v FIGURE 2 mountain range as Mount Dutton and is expected to have consid- erable orographically derived stream flows . Airstrip Creek drains the slopes of the mountains facing King Cove Airstrip and f I ows into De Ita Creek approximate I y one-ha If m i I e be I ow the proposed powerhouse location . Airstrip Creek appears to be the groundwater discharge area of a regional groundwater flow system acting in the area . Airstrip Creek contributes surface water inflows to Delta Creek over a Jon er period of time than )(A..)". ....... ,_ ? the other tributaries since e swam retains most of the run - off and then slowly releases river system. Based on the estimating techniques previously described in Appendix B of the Final Report (DOWLJ August 1982)J mean annual flow of Delta Creek at the mouth is calculated to be slightly over 90.0 cubic feet per second (cfs). At the proposed diver- sion weir I ocat i onJ the est im"ated mean annua I f I ow of De Ita Creek is 24.0 cfs (or approximately 27 percent of the total estimated mean annual flow at its mouth). A continuous stream gaging of Delta Creek near the proposed powerhouse location has been initiated and the pre I iminary streamflow data to date tend to confirm the estimates obtained for the dam site . Observa- tions on Delta Creek during stream gaging activities have also shown that Delta Creek has more stream flow below the airstrip than at the dam site due to the addition a I contribution of several downstream tributaries (_I\J ~ -\"~ t~ •.s. r .,~),. Delta Creek is of glacial origin and carries a high con- centration of sediments supp I i ed by the g I ac i er which covers some nine percent of the upper drainage area . The geomorpho- 1 og i c characteristics of ~De Ita Creek indicate that the stream has not yet reached a dynamic equi I ibrium and is I ikely to con- tinue to shift its channels due to large accumulations of al lu- vial materials. The creek has developed a wide flood plain near the airstrip as a result of the flattening of the stream gradient and a resultant lowering of the water velocity causes - 6 - '£ the stream to drop a large fraction of its sediment load in this area . The braided form of Delta Creek near the airstrip is par- tially contained by a dike that channels nearly alI of the flow to the northern branch . Over 90 percent of the total suspended sediment load carried by Delta Creek occurs during the summer monthsJ late May through early October . Glacier fed streams may have suspended sediment concentrations as high as several thousand mg/i . The major sediment load in Delta Creek is from ~ the glacier on Mount Dutton and only one tributary carries it ~ from this source . The other principal tributaries in the Delta ~ ~.:h Creek system., i .e .... the North Tributary and Airstrip CreekJ do ">f'-V~ ., not contribute substantially to the total sediment load. In particularJ the airstrip swamps 'filtrate most of the sediments before Airstrip Creek enters D~lta Creek diluting the sediment concentrations in I ower De Ita Creek . It shou I d a I so be noted that only the Mount Dutton tributary above the proposed dam site is of glacial origin and the other tributary above the proposed dam site I ocat ion is vi sua I I y observed to be most I y clear water with low sediment loads . High surface water velo- cities in the upper reaches of De Ita Creek cause I arger sed i- ment bed-load d i scharges. The lower reaches near and below the airstrip are where the larger size sediment materials drop out as the stream I oses most of its carrying capacity due to a change in stream gradient. Limited water quality information is given in Table 1 (the sampling locations are shown in Figure 1). The differing char- acteristics of Delta Creek tributary waters above and below the proposed dam site are indicated by differences in both the temperature and pH. Operation of the proposed project could improve the sedi- ment characteristics of Delta Creek below the proposed diver- - 7 - '? Date 10/12/81 10/12/81 12/12/81 10/12/82 1/8/83 TABLE 1 WATER QUALITY DATA, 1981/82 DELTA CREEK Location Glacial Tributary, 100' above Proposed Diversion Clear Tributary, 100' above Proposed Diversion Staff Gage Staff Gage Staff Gage Temp. (°C) 5.0 6 .0 5 .0 1.0 0 .5 Conductivity pH (Micromhos/cm) 5.1 290 ~ 7.0 76 6 .4 175 Suspended Turbidity Solids (NTU) (mg/£) ~ 6.1 24 sion weir . It is anticipated that most of the suspended load and the ~of Delta Creek wil I be trapped by the diver- sion weir and the water discharged from the penstock w i I I be mostly free of these sediments. However~ maintenance of the diversion weir wi I I probably require that the trapped sediments be occasion a I I y f I ushed or removed to an up I and site. The timing of any flushing operations should be regulated so that there is minimal water quality degradation . A summary of discharge measurements made to date is pro- vided in Table 2 . ~'-;v.... ~ TABLE 2 DISCHARGE DATA, 1981 /82 / cr) DELTA' CREEK Date September 17~ 1981 Oc t obe r 1 3 , 198 1 January 7~ 1982 March 26, 1982 June 30, 1982 October 12 , 1982 J ·an u a r y 8 , 1 9 8 3 FISHERIES Discharge (cfs) 57 27 16 22 113 41 25 Pink, chum and coho salmon are known to spawn in Delta Creek (ADF&G, 1982). The Alaska Department of Fish & Game 1960-1981 escapement estimates for pink and chum salmon in - 9 - De Ita Creek are given in Tab I e 3. Escapement f i gures are not available for coho salmon . Arnold Shaul, ADF&G Fisheries Biologist in Cold Bay when originally contacted in 1981 felt that the silver run in Delta Creek was probably smal I . No adult fish were seen during either site visit in 1981, but the stream was not walked i n its entirety below the air- strip . With the exception of the glacial tributary, juveni Je Dolly Varden were captured in minnow traps throughout the creek (Table 4 and Figure 1). Two trips were made to King Cove in August and October of 1982 by DOWL biologists to observe the upward extent of adult sa I mon in De Ita Creek. These trips were timed to correspond with peak spawn i ng periods as verified through discussions with Arnold Shaul of Alaska Department of Fish & Game. 1982 was an except i ona I year for both pinks and chums in this area of Alaska, with estimated escapements of 20,000 and 31,000 (Shaul, 1982). Loca l residents felt that the silver run was also larger than usual . Spawning and Rearing Chum sa I mon frequent I y spawn in the i ntert ida I zone but wi I I ascend short rivers . In Delta Creek chums primarily spawn in s I oughs and backwaters near Lenard Harbor, but a few wi II spawn as far upstream as the a i rstrip (Shaul, 1981). Chums begin entering Delta Creek around August first and peak spawn- ing occurs during the last 10 days in August and the first week in September . Pebb I e grave I (. 25 to 2 . 5 inch), is reported to be the preferred spawning substrate for chums (Wilson et.al., 1981). Optimum streamflow velocity and depth for spawning is 1.0 to -10 - TABLE 3 DELTA CREEK ESTIMATED TOTAL PINK AND CHUM SALMON ESCAPEMENTS ~J-·~,~ Year Pinks Chums ~·Y 1960 200 6~100 ~s 1961 <100 20~300 1962 tf § 00 1,500 1963 §100 12,200 1964 §100 12,800 1965 1~200 7,000 1966 §10'0 2~800 1967 §100 4~800 1968 §100 9~500 1969 §100 3~500 1970 §100 10~500 1971 §100 6,500 1972 §100 10,900 1973 §100 3,500 1974 §100 3,800 1975 §100 2~500 1976 §100 7~500 1977 2~700 22~800 1978 8,700 25,000 1979 1,200 2,500 1980 4,500 11,800 1981 1,400 12,000 1982 20,000~ 31,000~ ~ Estimate (ADF&G) ~ ~-l\~ fu- rJ hu.N--?. ~~ -11 - TABLE 4 SPECIES AND NUMBER OF FISH CAUGHT IN DELTA CREEK October 12-13J 1981 TraQ Location Juven i I es Caught Below the airstrip 4 Dolly Varden At the airstrip 6 Dolly Varden Above proposed powerhou?e site 11 Dolly Varden At the staff gage -~J-At _ _7, .. 1 Dolly Varden Between the staff gage and weir 1 Dolly Varden Glacial Tributary 0 Clear Tributary 7 Do I I y Varden 2.0 feet per second (ft ./sec.) and 1.0 to 2.5 feet (Wi lsonJ et ai .J 1981). Immediately upon their emergence from the graveiJ juvenile chum salmon migrate to saltwater. Pink salmon normally spawn intertidally or in the lower reaches of short coasta I streams . Pebb I e grave I (. 25 to 2. 5 inch) is preferredJ with an optimum streamflow velocity of 1.0 ft./sec. and a depth of .3 to 1.5 feet (Wi I son et al •J 1981). Loca I residents reported that pinks spawn in I ower De Ita Creek and in Airstrip CreekJ a tributary stream which joins Delta Creek about three-quarters of a mile below the airstrip. Pink -12 - salmon begin entering Delta Creek about the first of August but peak spawning does not occur unt i I the last 10 days of August through the first week of September (Shaul, 1981). Like chums, pink salmon migrate to saltwater as soon as they emerge from the grave I . On August 25, 1982 , stream counts were conducted on Delta Creek from approximately one mile above Lenard Harbor to ap- proximate I y one-ha If m i I e above the proposed powerhouse site (Table 5). The water in Delta Creek was highly turbid with glacial flour considerably I imit i ng visibi I ity . Visual counts therefore do not accurately represent total numbers of fish but can be used to judge reI at i ve abundance within the various stream segments . Delta Creek was waded upstream of the power- house so that f i sh movements wou I d aid in i n c reasing the ac - curacy of the count. Opt i mum cond i t i ons for spawning silver salmon are reported to be gravels of .08 and 1 .3 i nches , depths of .7 to 2 .0 feet , and velocities of 1.5 to 2 .5 ·ft ./sec . (Wilson et al., 198 1 ). Shaul had no information on where si Ivers spawn i n Delta Creek bu s suspected they spawn in sloughs at or near Lenard Harbor (1981). Shaul noted that s i Ivers probably begin enter i ng Delta Creek the last ten days of August but d i d not spawn unti I the later part of September and into early October . On October 13 -14 , 1982 , stream counts were conducted on Delta Creek from Lenard Harbor to the proposed dam s i te . Two observers , one on each streambank , were again used . Visibi I ity was cons i derab I y better than in August but was hampered by inclement weather and the type of habitat where silver salmon were typ i ca I I y found . The majority of sa I mon seen were ob- served in deep pools often in combination with undercut banks. Water depths ranged from 3 to 12 feet or more . S i Ivers prob- ab I y hoI d and ripen in these poo Is before ascending sma I I er tributaries to spawn . - 1 3 - - TABLE 5 DELTA CREEK STREAM COUNTS, AUGUST & OCTOBER 1982 Date August 1982 October 1982 Location Above the powerhouse Clear tributary aero ? . & below powerhouse Mainstem, powerhouse to ~rpo~ tributary ( ""'' '------- Mainstem, Airstrip Creek to 1st right tributary · ( Ri~ht clear tributaryj) partial / count ----- Estimated carcasses Estimated f-ish in remainder of c I ear tributary :> Airstrip Creek to Lenard Harbor -14 - Count 19 pinks 165 pinks 1,250 pinks 13 chums "') 1,800 pinks 1,500 pinks 1 s i I ver 1,000 pinks 1,000 pinks 48 s i Ivers No si Ivers were sighted above the junction of Delta Creek with Airstrip Creek but pools are uncommon in the upper sec- tions, and those present are small and comparatively shallow (<3 feet deep). When first emerged, juvenile coho salmon stay in gravelly shallows near shore. Older juveniles prefer deeper pools, and avoid riffle areas. They are strongly territorial and wi II defend their space from other j uven i I e cohos and sa I mon ids. Juven i I e s i Ivers were found in tributaries to De Ita Creek. Dol Jy Varden spawn in smal I gravel (.08 to 1.3 inch) in a fairly strong current (1.0 to 2.5 ft./sec.) in depth of .6 to 2.0 feet (Wilson et al., 1981). Juvenile Dolly Vardens are relatively inactive, often remaining on the stream bottom in pools or eddies under rocks· and logs or undercut banks. Several schools of 10 to 30 juvenile Dolly Varden were observed below the proposed powerhouse in 18-to 22-inch deep pools near undercut banks. Do I I y Varden occur in both anadromous and nonanadromous populations. If anadromous, juveniles spend three to four years in their natal stream before entering saltwater. CURRENT UTILIZATION OF FISHERY RESOURCES King Cove residents occas i ona I I y sport fish for Do I I y Varden in Delta Creek. Approximately five years ago, a sub- sistence fishery for si Ivers began in Delta Creek. Although responses from local residents were somewhat contradictory, it appears that most of the I ong term residents do subsistence fish this run with catches of up to 100 s i Ivers in one day reported. None of the residents contacted were aware of any use by si Ivers of the mainstream above the airport triburary. -15 - Some subsistence fishing for pinks and chums a I so occurs in De Ita Creek. Subsistence sa I mon fishing a I so occurs on the west side of Cold Bay~ where both si Ivers and sockeyes can be taken . Pinks and chums are taken in the King Cove Lagoon and in Ram Creek ~ to the southeast of town (Shaul~ 1981). ~ -'~ -• ~~~ L< ~ \ PHYSICAL STREAM DESCRIPTION ~ ~_' ~ f~~ ~-v \J),v ~~ '1 \\1 De Ita Creek begins at the conf I uence of a g I ac i a I and snow-melt stream at the 400 foot elevation . In September of 1981~ it was clear with a glacial tint. The creek can be di- vided into three sections : Section 1 is composed of both upper tributaries and the mainstem to the proposed powerhouse loca- tion at the airport~ Section 2 extends from the powerhouse lo- cation to the junction of Delta Creek with clear Airstrip Creek~ and Section 3 extends from the Airstrip Creek junction to sa I twater at Lenard Harbor. Photos 3 and 4 show a view of Delta Creek rapids and a typical side channel in Section 2 of the creek. The section of Delta Creek in the project vicin i ty is not nav i gab I e and has no es tab I i shed use as nav i gab I e or pub I i c waters . Lower portions of the creek near tidewater may be nav i gab I e but do not appear to be used by I oca I residents. Section 1 Above the proposed diversion site~ the left glacial trib- utary was fast flowing~ turbulent and silty. No pools and only minimal backwaters are present in this section. This tributary showed signs of periodic high flows with I arge unvegetated areas on either side of the stream. The streambed consisted of boulders and cobbles~ with pebble gravel -16 - No.3 Delta Creek, looking upstream No. 4 Typical side channel in lower Delta Creek where schools of juvenile Dolly Varden were seen present 1n less turbulent areas. Gravel in the streambed was densely packed and difficult to dislodge by kicking. The un- vegetated floodplain was composed of cobble and pebble gravel. The right tributary was clear and contained a lower volume of flow. One mile up the valley1 a waterfall approximately 60 feet high was observed. Near the junction, the current in the right tributary was fast but slower than that observed in the left tributary. Substrate in this right tributary was similar to that of the glacial tributary with 1/2-to 2-inch pebble grave I present in the I ower-ve I oc i ty areas. Green a I gae were present in deeper, less-turbulent areas of the stream. Approx- imately 90 percent of the stream was composed of riffles with the remainder consisting of pools and backwaters. The bank was vegetated to the water I i ne and it appeared that little seasonal fluctuation in streamflow occurs. Tem- porary increases in streamflow do occur during rain ·storms. Views of the clear tributary and the glacial tributary are shown in Photos 5 and 6. From the junction of these two upper tributaries to the airstrip, Delta Creek flows at a relatively fast rate cascading over and around sma I I bou I ders in the stream bed. Dry side channe Is and an unvegetated strip near the water indicated periodic high flows do occur. Section 2 Below the airstrip, the stream slows and abrades into several triangularly shaped channels. Gravel bars are unvege- tated but the I ow stream banks are covered with aIder. Low velocity areas in these secondary channels are used extensively -18 - No. 5 Clear tributary No. 6 Glacial tributary by juvenile Dolly Varden . Substrate ranges from cobble to peb - ble size gravel. Section 3 Approximately one-half mile below Delta Creek's junction with Airstrip Creek, the creek reforms into one meandering channel . Substrate in the lower Delta River ranges from one- ha If inch pebb I e grave I at the mouth to a sma I I cobb I e and pebble gravel mix near Airstrip Creek . Considerable sand and fines were present throughout th i s section of the stream, e i ther intermixed with gravel or as sand bars . Stream banks ranged from\. to ~et in he i ght, and were genera I I y a s i It - sand mixture w i th occas i on a I I ayers of unsorted grave Is . FISHERY IMPACT h¥~j! Construct i on activ i ty may temporar i ly increase eros i on and sedimentation in Delta Creek . Sedimentation could affect fish by interfering wi th or preventing respiration by incubating s a l moni d e gg s , loss of spawning gravel, and p h ysical dis t ur - bance to both adult anadromous fish and resident species. This could result in a temporary disrupt i on of salmon runs returning to Delta Creek . Proper construct i on techniques and timing should minimize this impact . The diversion weir w i I I trap some of the coarser sediments carried in Delta Creek, so that water released from the power- house wit I be carrying less sediment than before project con- struction. Diversion of flows wi II also reduce the bed load and velocity in the stream between the dam and powerhouse and may improve it as fishery habitat . -20 - The portion of Delta Creek between the diversion weir and the powerhouse may be dewatered during I ow f I ows and a major reduction in flow wi I I occur during plant operations . This may prevent Dolly Varden from uti I izing this stream section as they now do . However, severa I sma I I tributaries join De Ita Creek between the diversion weir and the powerhouse and this may partially offset the effects of flow diversion at the weir . PUBLIC REVIEW NONIMATION FOR WATERS IMPORTANT TO ANADROMOUS SPECIES Based on 1981 and 1982 field observations, conversations Alaska Department of Fish & Game biologists , and inter- views with I oca I residents, the enc I osed recommended de I et ion @ s been prov @iii) under A I aska Department of Fish & Game's "public review nomination for waters important to anadromous species". This recommended de I et ion on I y app I i es to that por- tion of De Ita Creek above its junction with the /tb rth tr i bu- tary. N \ REFERENCES Alaska Department of Fish & Game . 1982 . An Atlas to the Cata- 1 og of Waters Important for Spawning, Rearing and M i gra- tion of Anadromous Fishes, Southwestern Region 3 . Shaul, A. 1981-1982. Fisheries Biologist, Commercial Fisher- ies Division, Alaska Department of Fish and Game, Kodiak , Alaska (personal communication). -21 - W i I son, W. J., et ~. 1981. An assessment of Env i ronmenta I Effects of Construction and Operations of the Proposed Terror Lake Hydroelectric Faci I ity, Kodiak, Alaska. In- stream Flow Studies, Final Report. Arctic Environmental Information and Data Center, University of Alaska, Anchor- age, Alaska. -22 - State of Alaska Department of Fish and Game Public Review Nomination for Waters Important to Anadromous Species Addition _x_ Deletion Name of Waterbody (if known): Delta Creek --~~~~==---------------------- Location: Anadromous Waters Catalog Volume and Number Southwestern Region 3 USGS 1:63,360 Quadrangle or 1 : 250 .ooo ( i f 1 :6 3. 360 not avail ab 1 e) __ c.;;_o;;;;.;l;;;..;d;;...._;;B;;;.,;;a;;.,jy ..... ,:...-:..A;.;::l;.;:a:...:;s;.;.:k:.:a:...- Species Date(s) Observed Stage(s) (Spawning. Rearing, . Migration} ~ Chum Spawning, Migration Silver Spawning, Rearing, 1----- ~ Migration Cc.~~~mts: Please provide any clarifying infonnation. Also. please include a llilP tlf the area identifying the streu reach. This can be a copy of the map from the Anadroroous Waters Atlas. Tte stream section outlined in purple was walked and minnow trapped September 17-18, 1981 and October 12-16, 1981. No ac.ult silver salmon were seen and no juvenile silver salmon were caught. On September 11, 1981, Arnie Shaul, ADF&G Fisheries Biologist in Cold Bay stated that no spawning occurs irL this area. (Continued on reverse side). Mae of Observer (please print) Laurel A. Bennett Date: 1/7/83 Signature: Address: 4040 "B" Street Anchorage, AK 99503 On August 24-26, 1982, I again walked that portion of the stream outlined in purple. I saw 13 chums at the mouth of tributary 2012 (outlined in red), but none above that point. I did see pink salmon in this section of the stream, but none above the yellow dot on the enclosed map. On October 11-15, 1982, I walked Delta Creek from Lenard Harbor to the end of the stream as indicated on the 1:250,000 map. I saw no silvers above the right tributary {2012). Local residents indicated that tributary 2012 was utilized by silvers, but they weren't sure about any use of the mainstern above that junction.