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HomeMy WebLinkAboutAPA1935dappS <15 30( C " . .". DRAFT ALASKA DEPARTMENT OF FISH AND GAME SUSITNA HYDRO AOUATIC STUDIES REPORT NO.3 PART II.Chapter 6,Appendices AQUATIC HABITAT AND INSTREAM FLO ..... INVESTIG:.TIONS (MAY-OCTOBER 1983) ALASKA DEPARTMENT OF FISH AND GAME SUSITNA HYDRO AQUATIC STUDIES REPORT SERIES \ RECEIVED MAY 291984 ALASKA POWER AUTHORl~ DRAFT ALASKA DEPARTMENT OF FISH AND GAME SUSITNA HYDRO AQUA TIC STUDIES REPORT NO.3 PART II.Chapter 6,Appendices AQUATIC HABITAT AND INSTREAM FLOW INVESTIGATIONS (MAY-OCTOBER 1983) Edlled by: Christopher C.Est •• and Douglas S.Vincent-Lang Prepared for: ALASKA POWER POWER AUTHORITY 334 W.FIFTH AVE. ANCHORAGE.ALASKA 99501 TAD/donrep DRAFT APPENDIX 6-A Passage Reach Cross Section Data Tables May ID,1984 TAD/donrep DRAFT May 10,1984 Table 6-A-1.Passage reach cross section data table,Slough 9 -Passage Reach I,September 29,1983. Mainstem discharge =9,080 cfs. Distance Between Distance Between Point Points (ttl Depth (ftl Point Points (ftl Depth (ftlr:o 1 (LWEl 0.0 18 0.3 1.0 1.0 2 0.23 19 0.4 1.0 1.0 3 0.1 20 0.5 1.0 1.0 4 0.2 21 0.6 1.0 1.0 5 0.44 22 0.4 1.0 1.0 6 0.5 23 0.8 <;'0.1.0 1.0 ~7 0.5 24 0.9 I 1.0 1.0 8 0.4 25 0.7 1.0 1.0 9 0.4 26 0.6 1.0 1.0 10 0.3 27 0.7 1.0 1.0 11 0.4 28 0.7 1.0 1.0 12 0.5 29 0.6 1.0 1.0 13 0.3 30 0.5 1.0 1.0 14 0.3 31 0.5 1.0 1.0 15 0.2 32 0.3 1.0 1.0 16 0.3 33 (RWEl 0.0 1.0 17 0.4 TAO/donrep DRAFT May 10,1984 Table 6-A-2.Passage reach cross section data table,Slough 9 -Passage Reach II,September 29,1983. Mainstem discharge =9,080 cfs.. Distance Between Distance 8etween Point Points (ft)Depth (tt)Point P()ints (ft)Depth (ft)r.u 1 (LWE)0.0 13 0.6 1.0 1.0 2 0.1 14 0.6 1.0 1.0 3 0.1 15 0.6 1.0 1.0 4 0.2 16 0.6 1.0 1.0 S'-5 0.1 17 0.5 I 1.0 1.0 ~6 0.2 18 0.5,1.0 1.0~7 0.3 19 0.5 1.0 1.0 8 0.4 20 0.5 1.0 1.0 9 0.5 21 0.6 1.0 1.0 10 0.5 22 0.5 1.0 1.0 11 0.5 23 0.2 1.0 1.0 12 0.6 24 (RWE)0.0 TAD/donrep DRAFT May 10,1984 Table 6-A-3.Passage reach cross section data table.Slough 9 -Passage Reach III (TR4)August 25,1982. Mainstem discharge 13,400 cfs. Distance Between Distance Between Point Points (ft)Depth (ft)Point Points (ft)Depth (ft) 2.0" 1 (LWE)0.0 18 0.2 1.0 2.0 2 0.1 19 0.2 2.0 2.0 3 0.1 20 0.2 2.0 2.0 4 0.1 21 0.2 2.0 2.0 5 0.2 22 0.25 2.0 2.0 6 0.3 23 0.2 2.0 2.0 7 0.1 24 0.1 2.0 2.0 8 0.2 25 0.1 1.5 2.0 9 (RWE)0.0 26 0.1 15.5 2.0 10 (LWE)0.0 27 0.1 1.0 2.0 11 0.1 28 0.1 2.0 2.0 12 0.1 29 0.1 2.0 2.0 13 0.2 30 0.1 2.0 2.0 14 0.1 31 0.1 2.0 2.0 15 0.1 32 0.1 2.0 2.0 16 0.1 33 (RWE)0.0 2.0 17 0.1 TADjdonrep DRAFT May 10.1984 Table 6-A-4.Passage reach cross section data table.Slough 20 -Passage Reach I July 16.1983. Mainstem discharge'16.400 cfs. Oistance Between Distance Between Point Points (ft)Depth (ft)Point Points (ft)Depth (ft)r:o 1 (LWE)0.0 19 0.3 1.0 1.0 2 0.2 20 0.3 1.0 1.0 3 0.1 21 0.3 1.0 1.0 4 0.1 22 0.3 1.0 1.0 5 0.1 23 0.3 1.0 1.0 ~6 0.1 24 0.3 1.0 1.0I70.1 25 0.3~1.0 1.0 8 0.2 26 0.3---e 1.0 1.0 g 0.3 27 0.3 1.0 1.0 10 0.1 28 0.3 1.0 1.0 11 0.1 29 0.3 1.0 1.0 12 0.2 30 0.3 1.0 1.0 13 0.1 31 0.2 1.0 1.0 14 0.2 32 0.2 1.0 1.0 15 0.2 33 0.2 1.0 1.0 16 0.1 34 0.1 1.0 0.4 17 0.3 35 (RWE)0.0 1.0 18 0.3 TAD/donrep DRAFT May 10,1984 Table 6-A-5.Passage reach cross section data table,Slough 20 -Passage Reach II,July 16,1983. Mainstem discharge -16,400 cfs. Distance Between Distance Between Point Points (ft)Depth (ft)Point Points (ft)Depth (ft)-r:o 1 (LWE)0.0 18 0.3 1.0 1.0 2 0.1 19 0.2 1.0 1.0 3 0.2 20 0.4 1.0 1.0 4 0.2 21 0.2 1.0 1.0 5 0.3 22 0.3 1.0 1.0 ~6 0.2 23 0.3 1.0 1.0 \7 0.3 24 0.3 ~1.0 1.0,8 0.4 25 0.3 ...\1.0 1.0 9 0.5 26 0.3 1.0 1.0 10 0.3 27 0.2 1.0 1.0 11 0.4 28 0.1 1.0 1.0 12 0.4 29 0.1 1.0 1.0 13 0.4 30 0.2 1.0 1.0 14 0.3 31 0.2 1.0 1.0 15 0.3 32 0.2 1.0 1.0 16 0.3 33 0.1 1.0 1.0 17 0.3 34 0.1 TAD/don rep DRAFT Table 6-A-5 (continued). May 10,1984 Distance 8etween Distance Between Point pOinWlli Depth (ft)Point Points li!l ~1.0 35 0.0 40 0.1 1.0 1.0 36 0.0 41 0.1 1.0 1.0 37 0.2 42 0.1 1.0 1.0 3B 0.2 43 0.1 1.0 1.0 :i'-39 0.2 44 (RWE)0.0, ~ ,I S-- TAD/don rep DRAFT May 10,1984 Table 6-A-6.Passage reach cross section data table,Slough 20 -Passage Reach III,July 16,1983. Mainstem discharge =16,400 cfs. Distance Between Distance Between Point Points (ft)Depth (ft)Point Points (ft)Depth (ft) 1.0" 1 (LWE)0.0 18 0.3 1.0 1.0 2 0.2 19 0.3 1.0 1.0 3 0.3 20 0.3 1.0 1.0 4 0.2 21 0.2 1.0 1.0 5 0.2 22 0.1 1.0 1.0 6 0.3 23 0.1 :---.1.0 1.0"I 7 0.2 24 0.1 ~1.0 1.0,8 0.2 25 0.2 ~1.0 1.0 9 0.3 26 0.2 1.0 1.0 10 0.3 27 0.1 1.0 1.0 11 0.2 28 0.1 1.0 1.0 12 0.2 29 0.2 1.0 1.0 13 0.2 30 0.2 1.0 1.0 14 0.2 31 0.1 1.0 1.0 15 0.2 32 O.1 1.0 1.0 16 0.2 33 0.1 1.0 1.0 17 0.3 34 0.1 6' I ~ :I ':DO TAD/don rep May 10.1984 DRAFT Table 6-A-6 (continued). Distance Between Distance Between Point pOinl~o(ft)Depth (ftt Point Points (ft)Depth (ft) 1.0 35 0.1 39 0.1 1.0 1.0 36 0.1 40 0.1 1.0 1.0 37 0.2 41 0.1 1.0 1.0 38 0.1 42 (RWE)0.0 TAD/donrep DRAFT May 10,1984 Table 6-A-7.Passage reach cross section data table,Slough 20 -Passage Reach IV,July 16,1983. Mainstem discharge:16,400 cfs. Distance Between Distance Between Point Points (ftl Depth (ftl Point Points (ftl Depth (ftl-r:ll" 1 1.0 0.0 19 0.3 1.0 2 1.0 0.1 20 0.4 1.0 3 1.0 0.1 21 0.4 1.0 4 1.0 0.1 22 0.3 1.0 5 1.0 0.1 23 0.3 1.0 6 1.0 0.1 24 0.1 ~1.0 7 1.0 0.1 25 0.1 1.0 \8 1.0 0.2 26 0.3-.0 1.0 9 1.0 0.2 27 0.1 1.0 10 1.0 0.3 28 0.1 1.0 11 1.0 0.3 29 0.1 1.0 12 1.0 0.3 30 0.2 1.0 13 1.0 0.4 31 0.1 1.0 14 1.0 0.3 32 0.1 1.0 15 1.0 0.2 33 0.1 1.0 16 1.0 0.3 34 0.1 1.0 I 17 1.0 0.2 35 (RWEI 0.0 18 0.2 TAO/don rep DRAFT May 10,1984 Table 6-A-8.Passage reach cross section data table,Slough 20 -Passage Reach V,July 16,1983. Mainstem discharge =16,400 cfs.. Distance Between Distance Between Point Points (ft)Depth (ft)Point Points (ft)Depth (ft) 1.0" 1 (LWE)1.0 0.0 18 0.1 1.0 2 1.0 0.2 19 0.2 1.0 3 1.0 0.1 20 0.2 1.0 4 1.0 0.2 21 0.2 1.0 5 1.0 0.1 22 0.1 1.0 6 1.0 0.3 23 0.1 1.0 S'7 1.0 0.3 24 0.1 I 1.0 ~8 1.0 0.3 25 0.1 I ' 1.0,-9 1.0 0.2 26 0.1<)1.0 10 1.0 0.1 27 0.1 1.0 11 1.0 0.2 28 0.2 1.0 12 1.0 0.3 29 0.1 1.0 13 1.0 0.2 30 0.1 1.0 14 1.0 0.1 31 0.1 1.0 15 1.0 0.1 32 0.1 1.0 16 1.0 0.1 33 0.1 1.0 17 0.2 34 0.1 TAD/donrep DRAFT Table 6-A-8 (continued). May 10,1984 Distance Between Distance Between Point pOinl~o(ft)Depth (ftt Point Points (ft)Depth (ft) 1.0 35 0.1 45 0.1 1.0 1.0 36 0.1 46 0.1 1.0 1.0 37 0.1 47 0.1 1.0 1.0 38 0.1 48 0.1 If'1.0 1.0 1 39 0.1 49 0.1 ::h 1.0 1.0 40 0.1 50 0.011.0 1.0 41 0.1 51 0.1 1.0 1.0 42 0.2 52 0.1 1.0 1.0 43 0.2 53 0.1 1.0 0.5 I-44 0.2 54 (RWE)0.0 TAD/don rep DRAFT May 10.1984 ~ ( :p, I-~ Table 6-A-9.Passage reach cross section data table.Slough 21 -Passage Reach I.September 13.1983. Mainstem discharge·16.400 cfs. Distance 8etween Distance Between Point Points (ft)Depth (ft)Point Points (ft)Depth (ft) 1.0 1 (LWE)0.0 7 0.3 1.0 1.0 2 0.1 8 0.4 1.0 1.0 3 0.2 9 0.3 1.0 1.0 4 0.1 10 0.4 1.0 1.0 5 0.2 11 0.4 1.0 4.0 6 0.2 12 (RWE)0.0 The last four feet of the cross section are blocked by large boulders making fish passage impossible. TAD/donrep DRAFT APPENDIX 6-8 Analysis of the Influence of Local Flow Conditions on Fish Passage by Larry Rundquist and Janet Hearns Woodward Clyde Consultants 1984 May 10,1984 TAD/don rep DRAFT OBJECTIVE May 10.1984 The objective of this passage analysis is to estimate the flows that correspond to successful and unsuccessful passage within specific sloughs and side channels in the middle reach of the Sus-itna River. Thi s phase of the investi gation concentrates on I oca I fl ow condi'ti.tl ns only.It does not include an evaluation of the influence of mainstem discharge on the backwater at the mouth of a site or overtopping at the upstream end of the site which can also influence passage in these areas. TAD/don rep DRAFT METHODS Data Base May 10,1984 The data base for the slough passage ana lys is vari ed between sloughs. Available data at all sloughs included: o slough thalweg and water surface profiles, o at least one surveyed transect,and o aerial photography coverage of the slough for Susitna nainstem flows of 9,000,12,500,16,000,21,000 and 23,000 cfs. Many of the sloughs had several surveyed transects located on riffles or within pools of the sloughs which corresponded to staff gage or flow measurement sites.Rating curves were available for most flow measurement sites.Sloughs 9,9A,20,and 21 had transect data for one to three passage reaches within the slough;these transects had a width equa 1 to that of the water surface at the time of the survey,which usually corresponded to a relatively low flow. Analyses The available data were not sufficient to conduct a direct analysis of slough flows required for passage within the sloughs.An indirect approach was developed based on the concept of "at-a-station"channel TAO/donrep May 10,1984 DRAFT geometry relations introduced by Leopold and Maddock (1953).They used discharge measurement data at a number of gaging stations in the United States to obtain power relations for width and depth in terms of discharge at a particular station.These relations are given by They found that the geometry varied considerably between cross sections and thus,the coefficients varied.Many streams,however,had similar rates of change of geometry.Based on a sample of 20 river cross sections in the Great Pla-jns and the Southwest,Leopold and Maddock obtained average exponent values of 0.26 for width and 0.40 for depth. They found that the expon~nts are a function of the shape of the channel and the hydraulics of the flow. Further study has been made on relations of the hydraulic geometry of stream channels by Leopold,Wolman and Miller (1964).It was found that channels in the humid eastern United States and in the wet mountain area of the central and north Rocky Mount!ins have a slower rate of increase of width (low b)than those of channels in the semiarid Southwest or the High Plains.This is due,at least in part,to the typical shape of the channel cross section in the various regions.Some values of the exponents in the hydraulic geometry relations are given in Table 6-B-1. Li (1974)presented a theoretical development of hydraul i c geometry relations for channels in homogeneous,coarse alluvium and small TAD/donrep May 10,1984 DRAFT drainage basins.The assumptions of the derivation conclude that all particles on the boundary of the channel are at a condition of incipient motion at bank-full.Li obtained equations of the form: W=a 0°·24 D =c 0°·46 Tab 1e 6-B-1.Average values of exponents in the At-A-Station Hydraulic Geometry Relations (after Leopold.et.al.1964). I I ~, I b f Average values midwestern United States .26 .40 Brandywine Creek.Pennsylvania .04 .41 Ephemeral streams in semiarid United States .29 .36 Average of 15B gaging stations in United States .12 .45 Ten gaging stations on Rhine River .13 .41 Symbol s:Q discharge W channel top width W=a Qb 0 hydraulic depth o =c Qf '. TAO/donrep DRAFT May 10.1984 The exponents vary only slightly with the angle of repose of the bed and bank material and with the lift to drag ratio. Slough Geometry Relations.It has been noted that the width and depth of a stream channel increase at some uniform rate with increasing flow. This is not always true.however.A logarithmic plot of the width or depth with flow may be a curved line or it may be a series of straight line segments with one or more breaks in slope.These types of plots may be due to variability of bed and bank material type.a break in the slope of the banks.channelization at low flows.or some other nonuniformity in the bed and banks. Riffle transects with developed rating curves were available for Sloughs 9,11,and 21 and Upper Side Channel 11.The transect data were input to a computer program that uses the Manning equation to calculate the hydraul ic geometry and flow for a range of selected water surface elevations.The reach gradient was used for the energy slope and Manni ng n was vari ed unti 1 the output from the computer matched the rating curve reasonably well.All four transects were fairly well calibrated using a Manning n value of 0.110. Power form relations for hydraulic (mean).depth as a function of flow were developed from the computer model output.Exponents in the equations were 0.38 for Sloughs 9 and 11.0.39 for Slough 21.and 0.45 for Upper Side Channel 11.These compare well with the values reported by Leopold,Wolman and Miller (1964).The r.ange of coefficients from 0.13 at Upper Side Channel 11 to 0.26 at Slough 11 was enough to cause ~-'n·b _ TADjdonrep May 10,1984 DRAFT the range of flows for a single depth to be large.The coefficients were not correlated to the reach gradient,which was the only variable that was available for passage reaches which lacked transect data. Thus,the wide range of calculated flows for a given depth could not be reduced based on the available data base. The hydraulic geometry relations were modified by plotting the mean depth against the unit flow (total flow divided by top width).The resulting lines were straight and parallel (on log-log paper)and the variation in coefficients could be reasonably explained in terms of reach gradient variation (Figure 6-8-1).Additional transects without rating curves were input to the Manning equation computer model using the reach gradient and the average Manning n value of 0.110 to compute their hydraulic geometry;these data were also plotted on Figure 6-8-1. The resulting set of curves can be used to evaluate the unit f~ows for selected mean depths in a passage reach having a known reach gradient. Specific application of Figure 6-8-1 for the passage reach analysis is discussed in more detail in a subsequent section. Channe 1 top wi dth was a1so plotted agai nst flow (Figure 6-8-2).These curves for the four transects having rating curves were generally non-parallel and non-linear,indicating a bad fit to the power form equation presented above.This is likely due to the existence of shelf-like areas on some transects which cause a large increase in width for a small flow. TAO/donrep May 10,1984 DRAFT Passaoe Depth Definition.Passage depth is the depth of water at a transect which a fish must navigate through in order to proceed upstream.Using the mean depth as the indicator depth for fish passage i.-?>-'K TAD/donrep May 10.1984 DRAFT Table 6-B-1.Average values of exponents in the At-A-Station Hydraulic Geometry Relations (after Leopold.et.al.1964). b f Average values midwestern United States .26 .40 Brandywine Creek.Pennsylvania .04 .41 Ephemeral streams in semiarid United States .29 .36 Average of 158 gaging stations in United States .12 .45 Ten gaging stations on Rhine River .13 .41 Symbols:Q di scharge W channel top width W=a Qb D hydraulic depth D •c Qf -------- <I!".~ .1 .01 .02 .03 .04 .05 .06 .08 .10 .2 .3 .4 .5 .6 .7 .8 .9 1.0 6-8-1 q (cll/ltl Relation between mean depth and unit 41o<J 300 200 .2 .3 .4.S.6.7 .8 .9 1.0 2 3 4 S 6 7 8910 20 30 40 60 80 100 6-8-2 Q (ets) Relation between top width and total discharge. 1.0 •••.9 ••.8 •• .7 •.'.• ••••.6 ••••• ••••.5-••Q;l r I •,J.96 I •..~•-• .4 •~• Q.•..•a •..•'"•0 3 •:;l •0 •0.•-•• 0 d 0.11-0 d••1.27 • .2 ••I•o:ii 1.10 a'l~l •d •d. •1.27 l 1.27 I • .IL ----,!-.....L.__---IL-_-!-_-+_+----:!_-!-..! .1 .2.3.4 .5 .6 .7 .8 .9 1.0 d (Mean Depth,feet) 6-8-3 Relation between mean depth and passage depth. TAD/donrep DRAFT May 10,1984 is somewhat conservative,since the maximum depth can be as large as 50 percent greater than the mean depth.Use of the maximum or thalweg depth is not a very good indicator of passage since it often represents the depth at one location on the transect,and this location may not be connected to the maximum depth on an adjacent transect.A passage depth term has been developed which is simply an average of the mean depth and maximum depth of a transect.Thus,the passage depth for a I I I I I I I I I triangular-shaped transect would be the average of the mean depth,which is two-thirds of the maximum depth,and the maximum depth,which gives five-sixths of the maximum depth for the passage depth.The passage depth for a rectangu 1ar-shaped transect wou 1d be equa 1 to the max i mum depth,since the mean depth and maximum depth are equal.Most transects would fall between these two extreme cases.A relation was developed between passage depth and mean depth based on data from surveyed transects (Figure 6-8-3). Passage Depth Criteria.Criteria were developed for the depth required for passage as a function of passage reach length based on the experience of biologists familiar with passage conditions in the sloughs.Details of the development of the criteria are found elsewhere in the ADF&G report.The resulting criteria consisted of two sets of curves,each set containing two lines.One set of curves was developed for slough conditions with small substrate (less than 3 inches diameter),uniform transects,straight channel,and velocities less than 2 fps.These conditions are failoly typical in many of the sloughs.The other set of curves was developed for sloughs with large substrates, non-uni form transects,bra i ded channel with numerous dead ends,and velocities typically greater than 2 fps.Each set of curves had three TAD/don rep DRAFT May 10,1984 categories of passage separated by the two curves (Figure 6-8-4).The three categories are defined below: Successful Passage (unrestricted):fish access into and/or passage within the spawning area to spawning sites is uninhibited,and would not affect production in this area. Successful Passage With Difficulty &Exposure:fish access into and/or passage within the spawning area is accomplished,but with stress and predation;although a sufficient number of fish pass to allow continued production in the area,this condition,over a long period of time,could result in a reduction in production. Unsuccessful Passage:fish access into or within an area to a spawning area may be accompl i shed by a 1imited number of fish; howE'ver,if exposure to excessive stress and increased predation (which are associated with these conditions persist)the population would eventually be eliminated. The curves sepa~ating these categories are thus threshold conditions and are of most interest in this analysis. Passage Reach Length.The passage reach lengths were determined by ADF&G based on the thalweg and water surface surveys.This typically corresponded with the distance between pools.It was assumed that thE' reach length remained constant with flow,since pool stage did n0t vary substantially with change in flow,especially over the small range of flow considered in this analysis. /_~-Ii ~~• '.0 00 11"'"'-.--'........"......h <.11 .._ ..,1 <Ill'... o e..,.I..."••...»0...'M •,<0" _....S-.- e.......'..., i'.iiO..-...Itt-.-"".In 0.' ... ~....•w a •• o... 0.' ~.SS.G[!t[ACM I.E N«;TM lIn.I -'-...,..-...- -'-••--- -'-M.......... -'-••..-- • ~e .. __~S~.~":..:.~':.~'.. ~-~-::.:..~'~W~.~;.:.~D~;"~;~.:.:":.~-:~[~.:..::.-:.-----------0 ......h"ItUCM CilUTUI&eUlty[S _·1 _ • ....._••>11 . .,.........<a ,"... '.0 · %..••w ••a •• ••., ""$S.GE lII(aCH I.[NGTH I''''t Figure 6-8-4 Passage depth criteria as a function of passage reach length, ( -1<. TAD/donrep May 10,1984 DRAFT Application to Sloughs.The general application of the relations, criteria,and data described above is summarized in this section in the form of a series of steps.Specific applications to each slough depended on the database for the slough and is described in the following section. o Step 1 -Identify the number and location of all passage reaches in the slough. o Step 2 -Evaluate the length of the passage reach from the thalweg survey. o Step 3 -Identify the passage depths for threshold values corresponding to successful and unsuccessful passage based on the reach length and the passage depth criteria (Figure 4). o Step 4 -Determine the mean depths that corresponds to the identified threshold passage depths (Figure 3). o Step 5 -Evaluate the reach gradient corresponding to each passage reach from the thalweg survey. o Step 6 -Evaluate the unit flows corresponding to both threshold depths for each passage reach by using the curve with the applicable reach gradient (Figure 1). TAD/don rep DRAFT o Step 7 -Plot a width versus flow curve for all surveyed transects on the slough. May 10.1984 o Step 8 -Measure the width of flow at the surveyed transect and at each passage reach on each of the fi ve sets of aerial photographs. o Step 9 -Use the measured top width at the surveyed transect for each set of photographs to evaluate the slough flow for each of the photographs. o Step 10 -Modify the slough flow.if necessary.to account for upwell i ng or tri butary i nf1 ow between the surveyed transect and each passage reach. o Step 11 -Use the slough flow and the corresponding top width measured from the aerial photographs to define several points on a curve of width versus discharge for each passage reach. o Step 12 -Plot lines of constant unit flow at the values obtained for both threshold depths.The intersect i on of these 1i nes wi th the wi dth versus fl ow curve deve loped for each passage reach gives the total flow that corresponds to both threshold depths. TAD/don rep May 10,1984 DRAFT o Step 13 -Tabulate the required depths and flow for both successful and unsuccessful passage for each passage reach. TAO/donrep DRAFT Whi skers Creek May 10,1984 The data base for the Whiskers Slough Site that proved useful for passage analysis includes transects at the slough mouth and at the slough discharge site (AOF&G gage 10l.253)located in the slough above Whiskers Creek,and a thalweg profile for Whiskers Slough.Additional data include flow measurements in Whiskers Creek (AOF&G gage 101.2T2B). These flow measurements were not useful because neither the discharge site nor the creek thalweg have been surveyed.Thus,no reliable rating curve with which to generate a width-discharge curve could be developed for the creek site.Because both passage reaches are located below Whiskers Creek,the flow contributions of the creek had to be accounted for.This was done using the following approach. A rating curve was developed for the slough discharge site.The general method could not be used because the transect is located at a pool,and the general approach only applies to riffles.Once an appropriate Manning n and energy slope were selected for the flow site,the same values were used to generate a rating curve at the slough mouth.The width-flow curve at the slough mouth was plotted and used to generate width-flow curves for both passage reaches.It was assumed that the flow remained the ;ame between Passage Reach and the mouth.Once the width vs.flow curves were plotted for the ?assage reaches,total flow was found by locating the required unit flow on each of the curves. L,-_.~~-.,~?S _ TAD/don rep DRAFT Mainstem II Side Channel May 10.1984 The data base for Mainstem II consists of a thalweg profile and five surveyed transects located at two discharge $ites.one in each of the two forks.and three staff gage sites below the confluence of the forks. Photographic enlargements,available for mainstem flows of 9,000; 12.500;and 16.000 cfs.do not provide adequate resolution with which to generate width versus flow curves for the passage reaches based on the rating curve for the flow site.Therefore.passage flows are based on field observations by E.Woody Trihey and Associates. Slough 9 Since all three passage reaches had been surveyed.the passage analysis at Slough 9 was a straight-forward appl ication of the general approach to developing rating curves.No extrapolation of the rating curves beyond the limits of the survey data was necessary. Slough 9A The data base at Slough 9f1 includes a thalweg profile and four flow measurements taken on October 25,1982.Because the measurements were taken on the same day and span almost the entire length of the slough. they provide an indication of the volume of upwelling within the slough. Three of the discharge sites coincide with passage reaches I.II I.and V.Ra ti ng curves for these sites were developed us i ng the genera 1 TAO/donrep DRAFT Hay 10,1984 method described previously;the measured flows were used as a calibration check.The calculated and measured flows compared to within 7 to 9 percent. Passage flows at reaches II,IV,and VI were determined·using the top width vs.flow curves for passage reaches I,III,and V and applying adjustments for groundwater upwelling and relative differences in top width.This information was provided by AOF&G personnel. Slough 11 The data base at Slough 11 includes a thalweg profile and surveyed transects at the mouth and at a flow site about 1,000 ft upstream of the mouth.The qual ity of aerial photography at this slough ·is very poor; the only set of photos on which any resolution is possible is that which was taken at a mainstem flow of 21,000 cfs.This does not provide adequate information with which to generate width ver~us flow curves for the passage reaches based on the rating curve at the flow site. Therefore,passage flows are based on f·e1d observations provided by E. Woody Trihey and Associates. Upper Side Channel 11 Access analysis for Upper Side Channel 11 was based on the rating curve developed for the flow site at AOF&G gage 136.251.This site is coincident with Passage Reach 1.1.The overall gradient through both reaches is the same,and aerial photographs indicate that the width of flow at both sites is similar.Thus,the top width versus flow TAD{donrep DRAFT May 10.1984 curve that was developed directly for Passage Reach II was also applied to Passage Reach I.Because the slopes were the same for both reaches, a direct plot of passage depth vs.flow yields the same results. Slough 20 Rating curves for the three passage reaches in Slough 20 were calculated using the general methodology described previously and depth measurements from each site.There were no flows with which to calibrate these curves.The general method was not used to calibrate the rating curve at the flow site (ADF&G gage 140.155)because the site is located in a pool,and the method is only applicable at riffle sites. Because passage reaches were quite shallow at the time they were surveyed.their rating curves do not extend to the depths required for passage analysis.The curves were extended by scaling the width of each site,including the flow site,off the set of large scale aerial photographs (l "s50';ma i nstem flow equa 1 21,000 cfs).Assumi ng that flow within the slough remained constant.the width of each passage reach was plotted against the flow at the gaging site.This provided an extension that was sufficient to determine the total flow corresponding to the required unit flow at each passage reach. A1though the extens ions do not account for any upwell i ng if'the slough. the shape of the extended portions of the curves is such that the impact of disregarding this effect is not substantial. TAO/don rep DRAFT Side Channel 21 May 10.1984 Three of the five passage reaches in Side Channel 21 coincided with surveyed transects and/or flow sites at either staff gages or IFG study sites.Passage Reach III is located at the flow site situated at Transect 4 of the lower IFG study site (ADF&G gage 140.654).The rating curve was developed using the general methodology described previously using the flow measurements as a calibration check.No modifications to the rating curve or wi dth versus fl ow curve were needed in order to obtain the passage flows. Passage Reach IV is coincident with the transect surveyed at ADF&G gage 140.652.A rati ng curve was generated us i ng the genera I method and applied without modification. Passage Reach V is situated at the downstream end of the Upper IFG study site and is coincident with Transects 1-3.A rating curve at Transect 3 was developed using the general approach described previously.No changes were made to the rating curve in order to determine the passage flows. No data were availa~le at Passage Reaches I and II other than the aerial photo enlargements.Passage is not a problem.however,at the mainstem flows represented in the photographs,so they did not prove particularly useful for this analysis.Thus.for simplicity and lack of a better approach.the passage flows for Passage Reaches ·1 and II were taken from the width versus flow curve for Passage Reach III. TAO/donrep DRAFT May 10,1984 In addition to a surveyed thalweg.Slough 22 has surveyed transects at the mouth (AOF&G gage 144.3W3).mid-slough (AOF&G gage 144.354)and at the flow site just below the tributary (AOF&G gage 144.356).Aerial photo enlargements are available for a mainstem discharge of 21.000 cfs only. Rating curves were developed for the gage sites at the mouth and mid-slough.Both these sites are riffles,so the general method described previously was applicable.Passage Reach I coincides with the gage site at the mouth.so passage flows could be determined directly from the rating curve. Passage Reach II is situated about 300 ft upstream of the mid-slough gage site and has a reach gradient of 20.7 ft/mi as compared to 6.3 ft/mi at the mid-slough gage.The enlarged aerial photos taken at a mainstem discharge of 21,000 cfs indicate that Passage Reach II is roughly twice as wide as the mid-slough gage site.A width vs. flow curve for the passage reach was generated from the wi dth vs. flow curve for the mid -slough gage site by assuming that flow remained constant between the two sites.but at all .flow the top width at the passage reach was double that at the ga~e.The validity of the numbers obtained in this manner depends primarily upon how well the width relationship holds at flows other than the one shown in the aerial photos. TAD/donrep DRAFT RESULTS AND DISCUSSION May 10,1984 Table 2 sUlI'IIIarizes the results of the passage analysis for the nine sloughs in which passage problems were identified.Based on the existing data,the numbers presented are a reasonable estimate of the slough flows needed to meet the passage criteria for successful and unsuccessful passage.However,because the data were not easily applied to this type of analysis,it is strongly suggested that field verification of the calculated values be included in the 1984 field program. In addition,further field investigation may reveal additional passage problems that were not apparent on the thalweg and water surface surveys,and/or eliminate some reaches that were previously identified as problems. _r _TAD/donrep DRAFT . 4 Table 6-8-2.Summary of slough flows needed to meet passage criteria for successful and unsuccessful passage. SUCCEsSFUL PASSAGE -llIFFICULT PASSAGE Passage Mean Passage Mean Length Depth Depth Unit Flow Depth Depth Unit Flow Site PR (ft)(ft) (ft)Flow (ds)(ft) (ft)Flow (cfs) Whiskers Creek I 226 0.50 0.36 0.145 10.5 0.38 0.26 0.089 4.2 II 50 0.42 0.30 0.107 10.1 0.28 0.19 0.050 5.0 Hainstem II 1 Point 0.50 0.:16 ---5 0.35 0.24 ---3 II 200 0.67 0.49 ---5 0.50 0.36 ---3 III Point 0.50 0.36 ---5 0.35 0.24 ---3 IV 40 0.60 0.44 ---5 0.42 0.30 ---3 V 200 0.67 0.49 ---5 0.50 0.36 ---3 ~VI 260 0.67 0.49 ---5 0.50 0.36 ---3 ':P 9 I 167 0.48 0.34 0.073 2.3 0.35 0.24 0.041 1.2 II 292 0.67 0.49 0.137 3.2 0.50 0.36 0.080 1.7 ).::III 83 0.60 0.44 0.115 10.15 0.42 0.30 0.060 5.8oJ, 9A I 20 0.60 0.44 0.150 2.4 0.42 0.30 0.079 1.0 11 10 0.50 0.36 0.220 3.4 0.35 0.24 0.110 1.5 III 175 0.65 0.48 0.360 5.5 0.48 0.34 0.200 2.4 IV 10 0.50 0.36 0.078 0.5 0.35 0.24 0.040 0.2 V 130 0.62 0.45 0.270 2.8 0.45 0.32 0.150 \.4 VI 240 0.67 0.49 0.122 2.0 0.50 0.36 0.108 1.8 II J 35 0.42 0.30 ---4.0 0.28 0.19 ---2.5 II 35 0.42 0.30 ---4.0 0.28 0.19 ---2.5 III 61 0.42 0.30 ---4.0 0.29 0.20 ---2.5 IV 26 0.42 0.30 ---8.0 0.28 0.19 ---5 (right channel)V 30 0.42 0.30 ---4.0 0.28 0.19 ---2.5 (left channel)V 41 0.42 0.30 ---4.0 0.28 0.19 ---2.5 _"1"-TAO/donrep DRAFT Table 6-8-2 (continued) Upper Side Channel 11 1 40 0.60 0.44 0.22 16.0 0.42 0.30 0.115 7.0 11 670 0.67 0.49 0.26 20.0 0.50 0.36 0.155 10.1 20 I 90 0.42 0.30 0.091 3.4 0.30 0.20 0.046 1.6 11 100 0.43 0.30 0.091 4.1 0.30 0.20 0.046 1.9 1II 95 0.60 0.44 0.172 8.5 0.43 0.30 0.091 4.1 I Side Channel I 10 0.50 0.36 0.105 8.0 0.35 0.24 0.053 3.1 21 II 15 0.55 0.40 0.125 10.0 0.39 0.27 0.065 4.1 111 175 0.65 0.48 0.290 27.5 0.48 0.34 0.163 14.0 IV 200 0.67 0.49 0.240 30.0 0.50 0.36 0.145 16.5 V 200 0.67 0.49 0.079 4.2 0.50 0.36 0.065 3.2 22 I 40 0.60 0.44 0.118 14.0 0.42 0.30 0.063 3.6 II 220 0.67 0.49 0.257 9.0 0.50 0.36 0.154 20.0 TAD/donrep DRAFT LITERATURE CITED APPENDIX B May 10,1984 Leopold,L.B.,and Maddock,T.,Jr.,1953,The Hydraulic Geometry of· Stream Cr.~nnels and Some Physiographic Implications:U.S. Geological Survey Prof.Paper 252. Leopold,L.B.,Wolman,M.G.,and Miller,J.P.,1964,Fluvial Processes in Geomorphology:W.H.Freeman and Company,San Francisco. Li,R.M.,1974,Mathematical Modeling of Response from Small Watershed: Ph.D.Dissertation,Department of Civil Engineering,Colorado State University,Fort Collins,Colorado.