# 242;0
F P - 

### FD - M-C..;



# Washington Phase II Fish Diversion Screen 

# Evaluations in the Yakima River Basin , 1997
Prepared by: L. Blanton A. Neitzel s. Abernethy Pacific Northwest National Laboratory Richland , Washington

Prepared for: s. Department of Energy Bonneville Power Administration Environment Fish and Wildlife

o. Box 3621 Portland , Oregon 97208- 3621 Project Number 86- 118 Task Order DE- AT79- 9430373BPA Contract Number DE-AI79- 86BP62611

February 1998

# Acknowledgments
The successful completion ofthis project depended on the involvement and cooperation of many people. Jodi Stroklund , Bonneville Power Administration (BP A), 

### directed the project. John Easterbrooks , Washington Department ofFish and Wildlife (WDFW), provided valuable background information on the sites and also comments on the operation and maintenance of individual sites. Bill Mavros , Brett Tiller, and 

### Mike Blanton ofPNNL , Associated Western Universities students Jeff Marco and Jen Morse , and Science and Engineering Research Semester student Ginger White assisted 

### during field evaluations. Scott Abernethy and Bob Mueller provided valuable guidance 

### on equipment operation and Scott helped with data interpretation. Elementary and high school teachers ITom Richland , Kennewick, Pasco , and Toppenish , Washingtonalso assisted in data collection and summarization as part of a Department of Energy

### sponsored program entitled Partnership for Arid Lands Stewardship (PALS). Bill Mavros and Dennis Dauble (PNNL) reviewed a draft of the manuscript.

11l

# Summary
The Pacific Northwest National Laboratory evaluated 19 Phase II screen sites in the Yakima River Basin at least three times each between April 30 and August 22 , 1997. The sites were examined to determine if they were being effectively operated and maintained to provide fish a safe 

### , efficient return to the river. Data were collected to determine if velocities in ITont of the screens and in the bypass met current NMFS criteria and promoted timely fish bypass , if fish were protected ITom injury due to impingement, entrainment , and predation , and whether bypass outfall conditions 

### allowed fish to safely return to the river. A bi- directional flow meter and underwater video system were essential in completing the investigation. In general , water velocity conditions at the screen sites were acceptable by NMFS standards. High approach velocities and slow bypass flow were the most common problems noted. Although velocities often fluctuated ITom one sampling location to the next

### , average sweep and approach velocities were very good. In general , fish should not be impinged or experience delays in returning to the river under normal operating conditions. Most screens were properly sealed to prevent fish entrainment and injury, although 

### potential problems were identified at several screen sites. Three sites had gap openings ITom the forebay to the aftbay, allowing fish to be 

### entrained. Other sites had spaces larger than 3/32 inch where small fish could become trapped. Some drum screens had flat spots but these were not been confirmed as underwater gaps 

### , primarily because of 

### siltation. On rare occasions , seals were intact, but cracked or turned under. Submergence levels at the drum screen sites exceeded 85% for one third of our evaluations. Eight of 12 drum screen sites experienced high water levels during at least one evaluation. Only one operating site s submergence was measured at less than 65% 

### submergence. Two flat plate screen sites were completely overtopped with water 

### during one evaluation each. Although 1997 was an extreme high-water year , these 

### overtopping events point out that some screens do not completely protect fish under the full range of potential operating conditions. 

### Water depths at the outfall pipe were acceptable at all but four sites. Generally, 

### water depths were low near the end ofthe irrigation season due to low river flows. Rock removal around the outfall pipe or pipe extension would improve the situation. We gauged the potential for predation by qualitatively measuring the types and 

### amount of cover provided for predators in ITont of the screens and by recording random observations of fish large enough to be considered predators in the fore bay. Predation was more likely to occur at drum screen sites than at flat plate screen sites. Drum sites provide more predator hiding places because greater amounts of woodydebris accumulate under the drums and against the concrete walls that divide one

screen bay ITom the next. Four sites had both woody debris and large fish present. These four sites were considered most likely to experience juvenile salmonid loss to predation. . Periodic removal of woody debris ITom underneath the curvature of drum screens would decrease the likelihood of predation at these sites. Screens were generally well maintained. Automated cleaning brushes functioned properly, chains and other moving parts were well greased , and inoperative and algae

### covered drum screens were eventually repaired and cleaned. However 

### , removal of sediment build-up and accumulated woody debris are areas where improvement should be considered. Maintenance checks should include observation of bypass outfalls on a regular basis , as conditions at the end of the bypass pipe are likely to change seasonally, especially in streams with high gradients or unstable gravel. 

### Post-season evaluations were conducted at 11 sites in November to try and confirm seal and drum screen defects , and locations of excessive sedimentation. This proved effective in several cases , but the winterization process eliminated some ofthe evidence. Several forebay areas had already been cleared of silt. It was difficult to evaluate screens and seals when the screens were in the storage position because the 

### screens could not be rotated. Also , two sites remained in full operation while others were submerged , precluding detailed examination of parts still under water.
Periodic , regular screen evaluations will increase the effectiveness of screen operation and maintenance practices by confirming the effectiveness (or ineffectiveness) 

### of screen operating procedures at individual sites. Where procedures are being followed and problems still occur, evaluation results will suggest means to improve the procedures to better protect fish at screening facilities.

# Methods
Nineteen operating screen sites in the Yakima, Naches , and Tieton River basins were evaluated between April 30 and August 22 , 1997 (Figure 1).

1. Snipes- Allen 2. Union Gap 3. Taylor 

## 4. Bull 

## 5. Ellensburg Mill 6. New Cascade 

## 7. Fruitvale 8. Toppenish Pump 9. Naches - Cowiche 10. Congdon 11. Gleed 12. Kelley - Lowry 13. Clark 14. Naches- Selah 15. Lindsey 16. Yakima - Tieton 17. LowerWIP 18. Bachelor - Hatton 19. UpperWIP

. Screen Site

Figure 1. Yakima River Basin Phase II Screening FacilitiesEach ofthe 19 sites was visited three times. The three rounds of evaluations were

conducted during early May, late June/early July, and mid August. Three types of data were collected. These included water velocity measurements (Figure 2), underwater video footage , and general data (i. , screen submergence , bypass conditions , fish presence , operator aids). During the first evaluation , video footage was not acquired 

### due to high water turbidity. The third evaluation was the only round during which nets were placed immediately downstream of the screens to capture and identifY fish found in irrigation canals. Eleven screen sites were visited on November 20 

### 1997. The purpose was to examine screen sites while 

### forebays were relatively dry. It was our intention to confirm information ITom underwater video data 

### collected during previous investigations. Some factors considered were silt and debris accumulation seal integrity, and screen condition. Figure 2. Underwater Video Equipment and Water Velocity Probe. 

### Velocity Measurements Equipment Water velocities in ITont ofthe screens and in the bypass were measured with a Marsh McBirney Model 511 (B) 

### electromagnetic water current meter. The meter used a bi- directional probe (Figure 3) that allowed measurement of flows in two directions (approach and sweep) simultaneously. Output was read visually ITom a panel gage. The probe was securely mounted to a horizontal arm that extended approximately 12 inches ITom a vertical pole. The length of the horizontal arm and its position on the 

### vertical pole were adjustable. The probe support assembly was positioned at least 12 inches downstream or outside the probe s sensors to minimize interference ITom the vertical pole when taking velocity readings.

Cross Section of Probe

Clamping Surface 

# Cable probe

Figure 3. Bi- directional Electromagnetic Probe Used for Measuring Water VelocityAt several sites with very small drum screens , a smaller, unidirectional electromagnetic water current meter probe (Marsh McBirney Model 2000CBJ) was used 

### to measure velocity because it could be placed closer to the bottom of the screen than the bi- directional probe.
Probe Positionin Velocity measurements were taken in ITont of all screens. The vertical pole was placed close to the ITont of the screen , but was never in contact with the screen face. The bottom of the pole rested on the concrete forebay floor (usually on the raised sill), but the pole was not allowed to come in contact with metal (e. , walking platform 

### gantry, or girder), to reduce the likelihood of electrical interference. The probe was mounted on the horizontal arm so that it pointed upstream and was positioned within 3 

### inches of the screen face. Because the screens are constructed at an angle to the canal flow , all measurements were taken with the probe orientation parallel (sweep) and perpendicular (approach) to the screen face 

### , not to canal flow. Measurements were taken across the screen face at 0.2 and 0. 8 ofthe water depth. Velocity measurements were taken at either three or five evenly spaced positions across each screen or panel. 

### Velocities were also measured in the bypass. Two measurements were recorded. The first was taken immediately inside the vertical slot bypass entrance at mid water depth. The second was recorded halfway between the bypass entrance and the overflow weir, again at mid water depth. Data Collection and Anal sis Flow measurements were taken in ITont of every screen during all three site visits. Power to drum screens and cleaning brushes was disconnected to decrease the 

### likelihood of electrical interference. An average:t standard deviation of the sweep and approach velocities at each site was calculated for each visit.



### Underwater Video Surveillance

ment An underwater video system was used to investigate screen seal condition , and to monitor debris build-up and fish presence. The system consisted of a high-sensitivity remote camera (Sony, model HVM- 

### 352~ with a wide-angle lens (700 Sony, model 

### VCL- 06HSCBJ ). The camera was housed in a water-resistant case (Sony, model WPC1401ID) and connected by 66 feet of quadraxial cable to an 8-mm camcorder (Sony, model CCD-FX71O Handycam Hi- 8IID

### ) in a weatherproof housing. The case was fitted with external weatherproof controls , a 4- in black and white monitor , and internal 

### battery power supply for the system. The underwater camera operates at extremely

### low light levels (..::: 1 lux), so that artificial light sources were not necessary to obtain

video images during daylight hours. Camera Positioning The camera was securely mounted under a horizontal arm that extended approximately 15 inches ITom a vertical pole. The length of the horizontal arm and its position on the vertical pole was adjustable. The camera was usually angled slightly 

### downward to observe the area between the screen and the bottom seal where there was 

### a potential for finding gaps. The camera was moved ITom upstream to downstream following the side and bottom seal/screen interfaces. Flatplate screens had vertical 

### seals between panels that were also observed and recorded on videotape. Where there were signs of excessive debris or of fish presence , images were also recorded showing the forebay area and/or bypass. Data Collection and Analysis Video footage was recorded only during the second and third site visits because 

### high turbidity (:::-6 NTU) precluded video analysis during the first round. All screens 

### and seals were videotaped during each of the two evaluations. Written observations were also made when something of interest was seen (i. e. faulty seals , gaps 

### , fish). Thevideotapes were reviewed in detail using a video cassette recorder (Sony, model EVC200 Hi- 

### 8~ and a 12- in black and white video monitor (panasonic , model TR- 124- MA lID ). Images of interest were digitized using Snappy Video Snapshot lID Version 2. software.


### General Data Collection

Other data collected included: general site descriptions and photographs screen and seal conditions screen submergence levels cleaning system operation and the incidence of headloss across the screen face bypass flow conditions bypass outfall flow conditions fish presence in ITont of and/or behind screens observations of debris in the forebay or bypass 

### the presence or absence of operator control aids such as water gages and drum submergence marks on screen ITamesThese data were recorded during every site visit , with the exception of fish 

### presence behind the screens. In August , fYke nets were placed behind screens at 9 sites including Clark, Congdon , Ellensburg Mill , Kelley Lowry, Lindsey, Naches Cowiche Snipes Allen , Taylor

### , and Upper WIP. The nets , made of 1/8 in. knotless netting, were 

### attached to rectangular metal ITames that could be adjusted to fit the width of the canal 

### or gate opening. The ends of the net were cinched shut with cable ties. The nets were usually placed immediately behind a gate allowing water into the irrigation canal. By shutting off the flow to all gates but the one where the net was placed , we could direct a strong current into our net and be reasonably certain that any fish entering the canal was captured. The nets were put in place at mid-afternoon and checked for fish after dusk and 

### then again in the morning, after dawn. Retrieval took less than 10 minutes. The nets were emptied , cleaned 

### , and repositioned if they were to be checked again. Fish found in the nets were identified to species if possible , and measured. Fork lengths were recorded for all fish; head widths were recorded for very small fish. Live fish were returned to the river ITom which they had come , below the diversion dam.

## Discussion and Recommendations
Fish screens in the Yakima Basin are designed to direct fish that have been diverted ITom a river and into irrigation canals back to the river without killing or injuring them 

### or delaying their migration. This study was designed to determine if screen sites are being operated and maintained in a manner that promotes safe fish passage. Data were collected to determine if: flows in ITont of screens promote fish bypass without chance of delay or impingement screens are adequately sealed to prevent fish injury or entrainment screen submergence levels preclude fish roll-over or entrainment, yet promote debris removal bypass outfall conditions promote safe fish access to the river conditions in ITont of screens deter predation of juvenile salmonids



### Water Velocities and Flows

In most instances , water velocity conditions at the screen sites were acceptable by NMFS standards. Although velocities often fluctuated ITom one sampling location to the next 

### , average flows were very good. For the most part, fish should not become 

### impinged or experience delays in returning to the river. However, some instances where further attention should be directed are highlighted below. 

### Bachelor Hatton Nearly 13% of all approach velocity measurements at Bachelor Hatton exceeded the 0.4 fps criteria. Approach velocities in ITont of the screen closest to the bypass were usually highest , sometimes reaching 0. 8 fps. This flow balance problem can probably be corrected (or reduced) by adjusting porosity boards. Water flow over the adjustable bypass weir was never set in compliance with 

### proper operating criteria, which suggest flow depth over the weir should be 0. 9 to 1. ft to achieve a bypass channel entrance velocity about 1. 5 times greater than the velocity in the screen structure fore bay area. Maximum depth over the weir during our evaluations was 0. 

### 38 ft. This caused sediment buildup at the entrance to the bypass. It also explains why bypass flows at Bachelor Hatton were always less than the average sweep velocity in ITont of the screen structures. This condition could potentially delay fish passage through the bypass. During part of the summer, almost all Ahtanum Creek was diverted upstream at the Upper WIP site 

### , leaving the streambed near Bachelor Hatton dry. At this time the

### bypass at Bachelor Hatton was blocked. This is acceptable as long as the stream is



### low. However, when stream flow is adequate there should also be adequate bypass flow and the bypass should be opened to allow for fish passage.



### Bull More than 36% of all approach velocity measurements at Bull exceeded criteria. The maximum approach velocities measured were 0. 

### 6 fps. High velocities were recorded in ITont of both panels , both at 0. 

### 8 and 0.2 ofthe water depth. It may be possible to adjust the baffles behind the screen to reduce approach velocities.
Cone:don The mean approach velocity for the Congdon site was just 0.41 fps , but there were 

### values recorded as high as 0. 8 fps. Just over 31 % of all approach velocity 

### measurements exceeded criteria. High values were recorded in ITont of all three screens. Generally, the highest values were recorded at the upstream end of each screen. Although both high submergence and high approach velocities occurred at this site , review of usage/withdrawal rates did not indicate that more screen area is needed to meet NMFS criteria. 

### Fruitvale Nearly 13% of all the approach velocity measurements recorded at Fruitvale exceeded criteria. The highest velocities were recorded in ITont of the panel furthest upstream. The maximum value recorded was 0. 65 fps. Slight 

### adjustment ofthe baffles behind the upstream panel could be made to reduce flow through this section of the screen. Toppenish Pump Toppenish Pump had the highest percentage of approach velocity values that 

### exceeded criteria (43%). The average approach velocity at this site was 0.46 fps. Conditions were most favorable to safe fish passage during the August evaluation when approach velocities averaged only 0. 31 fps. Differences noted between this evaluation 

### and those previous were that porosity boards behind the four most upstream screens had been removed and that the screen furthest upstream had been cleaned and was operational.


### Union Gap Bypass flows at Union Gap were always slower than the average sweep velocity in the screen structure fore bay area. According to the operating criteria , adequate water

### was flowing over the bypass weir. Bypass flow was fast, compared to other sites evaluated , however it was sluggish in relation to the site s average sweep velocity. 

### This does not promote rapid movement of fish into the bypass. It may be necessary to increase bypass flow requirements at this site or make other adjustments to bring this site into compliance. 

### Upper WIP Nearly 18% of all approach velocity measurements at Upper WIP exceeded 0.4 fps. These high flows were all recorded during June and July. The fastest velocities occurred in ITont of the screen furthest upstream , although velocities exceeding criteria were recorded in ITont of all four screens. During June and July, bypass flows were extremely low compared to sweep velocities in ITont of the screens. This probably 

### contributed to the increased approach velocities. Bypass flows may have been slow 

### because of blockage at the outfall. Rocks that had accumulated near the end of the pipe due to streambed shifting were removed after data was collected in July. Bypass flows improved immediately. 

### Yakima Tieton
Almost 11 % of all approach velocity measurements at Yakima Tieton exceeded 

### criteria. Approach velocities were high (up to 0. 8 fps) in ITont of the six upstream panels. Baffles behind these panels should be adjusted to create slower, more uniform flows through the screen.



### Seals Most screens were properly sealed to prevent fish entrainment and injury, although 

### gaps were identified at several screen sites. Some gaps are open ITom the forebay to the aftbay, allowing for fish entrainment in the canal. Other gaps were spaces larger than 3/32 inch where small fish can become stuck and face potential injury or death. Some drum screens had flat spots that were visible above water but could not be confirmed underwater, primarily because of siltation. In this case , a little sediment may 

### be a good thing if it blocks a potential entrainment pathway. On rare occasions seals 

### were cracked or turned underneath the drum screen ITame. Sites with gaps or other seal problems are identified below. Again , screens are numbered starting with the screen furthest upstream. 

### Bachelor Hatton Gaps between the screen and the bottom seal large enough for fish to become entrained were observed with the underwater video system at Screens 2 and 4. It was unclear whether the rubber seal or the drum shape was the cause , but the gaps shouldbe sealed prior to the 1998 irrigation season to protect juvenile salmonids ITom

entrainment. Cone:don A gap between the screen and the bottom seal large enough for fish to become 

### entrained was observed with the underwater video system at Screen 3. Flat spots 

### observed in Screens 1 and 2 may create gaps along the bottom seal , although this was 

### not apparent with the underwater video camera. 

### Ellensbure: Mill A small hole exists between Panels 1 and 2 where they meet at the bottom. Panel 2 was installed slightly higher than Panel 1. It is unclear whether the hole was open all 

### the way through to the opposite side , but any small gap big enough for a fish to enter is a potential injury site. 

### Gleed Impacts ITom large woody debris at Gleed have damaged some screen material. 

### Screen 4 wires have been bent enough to allow entrainment of small fish. The other screens should be examined closely to make sure they do not have gaps as well 

### , if screen material replacement does not occur prior to the 1998 irrigation season. The screen material currently used at Gleed did not meet NMFS guidelines for mesh opening sizes and may not provide enough entrainment protection for bull trout

(Salvelinus malma) and resident rainbow trout/steelhead (Oncorhynchus mykiss) stocks. 

### Naches Selah Sealant appeared to be missing along the bottom seal in several places , including areas under Panel 1 , between Panels 1 and 2 , and between Panels 3 and 4. 

### New Cascade A gap between the screen and the bottom seal , large enough for fish to become entrained 

### , was observed with the underwater video system at Screen 7. Flat spots observed in Screens 6 and 8 may have created gaps along the bottom seal , although this 

### was not apparent with the underwater video camera.

Snipes Allen 

### Flat spots were observed in Screens 1 and 2 that may have created gaps along the bottom seal , although this was not apparent with the underwater video camera.

### lor Small flat spots were observed in Screens 1 and 2 that may have created gaps along the bottom seal. Also , a stick may have punctured one side seal (not identified by screen number), as was shown in Figure 8a. 

### enish Pum The upstream seal at Screen 2 was folded underneath the metal ITame. All side 

### seals at this site appeared to be too short to adequately span the distance between the ITame and the drum. Replacing the side seals for every drum screen with wider ones 

### would ensure that other side seals do not turn under in the future. Underwater video also showed what appeared to be a cracked side seal (not identified by screen number), as was shown in Figure 9. 

### er WIP Underwater video footage at this site showed a small fish caught in the crack 

### between the screen ITame and concrete divider at the downstream end of Screen 3. may be advisable to seal these gaps with a " soft" seal that is not permanent and that would not hinder raising the drums for storage in the fall , if further evidence of fish injury or death in these small cracks is uncovered. 

### Submergence Submergence levels at the screen sites often exceeded 85%. High water levels occurred across the three site visits , not only during the period of high Spring runoff, as 

### shown in Table 7. Eight of 12 drum screen sites experienced high water levels during 

### at least one evaluation. This creates an opportunity for small fish to be carried over the 

### screens and down the canal. Only one operating screen site s submergence was ever 

### measured at less than 65% submergence. This can keep a screen ITom properly selfcleaning although this screen site appeared to be ITee of small debris. Two flat plate screen sites were completely overtopped with water during one evaluation each. 

### Although 1997 was an extreme high-water year, these overtopping events point out that some screens do not completely protect fish under the full range of potential 

### operating conditions. Although it may not be practical using physical barriers to completely prevent entrainment under extreme conditions , every reasonable effort should be made to locate and construct facilities to protect fish during spring ITeshet 

### conditions. Fish swimming at the water surface could easily enter the irrigation canal during these periods. Drum screen sites that were observed exceeding 85% submergence are Clark Congdon , Kelley Lowry, Lindsey, Lower WIP , Naches Cowiche , Snipes Allen , and 

### Taylor (Table 7). The site that was less than 65% submerged was Lower WIP on 4/30/97.Flat plate screen sites that were overtopped were Bull and Fruitvale (Table 7).

It is highly recommended that marks indicating the range of preferred submergence levels be painted directly on at least one drum screen ITame at each site. Operations personnel can then easily determine when a screen is outside the range and make 

### adjustments to headgate settings , porosity boards , or submergence gates (if present) to keep it operating properly and to keep fish out of the irrigation canal.

Table 7. Evaluation Periods When Screen Sites Exceeded 85%

Screen Site Period 1 Period 2 Period 3

(April and May 1997) (June and July 1997\ (Au!!:ust 1997) Drum Screens Clark 

### Congdon Kelley Lowry Lindsey Lower WIP 

### Naches Cowiche Snipes Allen 

### Taylor
Flat Plate Screens Bull Fruitvale

Bypass 

### Outfall Conditions Water depths at the outfall pipe were acceptable at all but four sites. Clark Fruitvale , Lindsey, and Upper WIP all had shallow water depths at the pipe exit during at least one evaluation period. 

### Water depths were low at Clark, Lindsey, and Upper WIP near the end of the 

### irrigation season due to low river flows. However, fish movement in August is usually low and the impacts of shallow water at the bypass outfall are probably negligible. Usually, just a small amount of rock removal around the area next to the outfall pipe 

### would greatly improve the situation. Water was low at Fruitvale at the beginning of the
season. A one- foot pipe extension would ensure that fish were safely returned to the creek. 

### Bypass pipes were often a smaller diameter than recommended by NMFS. The WDFW and BOR have largely disregarded this criterion because they feel it adds 

### unnecessary cost to the projects (Easterbrooks , pers. comm. ). Because the sites havetrashracks that keep out the large floating debris , these agencies assume that even the smaller pipe diameters will be able to pass the design bypass flow and any debris likely 

### to enter the pipe. We did not observe any bypass pipe blockages during our evaluations. The Lower WIP site , however

### , did appear to back up water near the pipe entrance. The pipe diameter was 

### measured at just eight inches. Further evaluations should monitor bypass flow at this site , as results ITom this year s studies are not 

### definitive. Should this pipe size prove to slow fish passage to the river, installation of a wider pipe should be considered.


## Predation Predation of juvenile salmonids at a screen site would be difficult to measure without employing additional expensive and labor- intensive methods of observation. Instead , we gauged the potential for predation by qualitatively measuring the types and 

### amount of cover provided for predators in ITont of the screens and by recording 

### random observations offish large enough to be considered predators in the forebay. Predation is more likely to occur at drum screen sites than at flat plate screen sites 

### because there are more hiding places for large fish to hide at these sites. For example 

### greater amounts of woody debris tend to accumulate underneath the curvature of the drums and against the concrete walls that divide one screen bay ITom the next. Screen sites with excessive woody debris were Bachelor Hatton , Congdon , Naches Cowiche 

### New Cascade , Taylor, Toppenish Pump, and Upper WIP. Woody debris was also observed in the bypass at Naches Selah and in ITont of screens 

### at Gleed. The debris at Naches Selah could be considered good cover for predators but the water velocities at Gleed are high and therefore not conducive to fish lying in wait, making predation unlikely. Relatively large fish , some of which were potential predator species , were observed with the underwater video camera in the forebays of Bachelor Hatton , Ellensburg Mill 

### Naches Cowiche , New Cascade , Toppenish Pump, and Upper WIP.
Thus , sites that had both woody debris and large fish present were Bachelor Hatton Naches Cowiche , New Cascade 

### , Toppenish Pump, and Upper WIP. These four sites should be considered most likely to experience juvenile salmonid loss to predation. 

### Periodic removal of woody debris ITom underneath the curvature of drum screens could help decrease the likelihood of predation at these sites.

### Operations and Maintenance Screens were well maintained at most sites. Automated cleaning brushes functioned properly, chains and other moving parts were well greased , and inoperative 

### and algae-covered drum screens were repaired and cleaned. However

### , removal of sediment build-up and accumulated woody debris are areas where improvement should be considered. Sediments blocking the flow of water through the screen can affect sweep and approach velocities and contribute to the increased incidence of screen 

### submergence above 85%. Woody debris that has lodged underneath the curvature of 

### drum screens cannot be seen ITom above water , but should be removed regularly. Sticks and logs affect flow past the screens and provide cover for piscivorous fish. They can also potentially block bypass pipes. Maintenance checks should include observation of bypass outfalls on a regular basis , e. g. weekly. Often , the removal of small rocks ITom the outfall area dramatically improves bypass flow and increases the water depth ITom the outfall pipe to the channel , allowing fish safe passage ITom the bypass into the river. Conditions at the end of the bypass pipe are likely to change seasonally, especially in streams with high 

### gradients or unstable gravel. It is also possible that blockages at the end of the bypass pipe could be diagnosed behind the ramp in the fish bypass structure. A visual aid at the bypass structure could identifY when a problem at the outfall exists. Screens were not always operated according to established operating procedures. 

### Bypass flow was not always adequate , and screens were over and under-submerged. 

### We sometimes encountered operations personnel at the sites. Generally, they corrected bypass flows but did not concern themselves with screen submergence. Changes to the screen system were often made subjectively. Gates were opened and closed until water flows " 

### looked right" 

### , not until a particular operating criterion was met. Again submergence marks on drum screens and marks on the overflow bypass weirs indicating how much water is cresting over the top would be a simple means to 

### enhance compliance with operating procedures. Since screen tenders keep a log of activities , information about submergence and bypass flow could be more easily documented if operator aids were present. Table 8 summarizes the areas where attention should be directed to improve fish bypass at individual screen sites.Table 8. Summary of Problem Areas at Individual Screen Sites

Drum Screens

Vertical Plate Screens Screen Site

Bachelor Hatton Clark Congdon Kelley Lowrey Lindsey Lower WIP Naches Cowiche New Cascade Snipes Allen Tavlor Toooenish Pumn Upper WIP Bull Ellensburg Mill Fruitvale Naches Selah Union Gao Yakima Tieton 

### Vertical Gleed Traveling Screen oS- ...,.

-5 d ~ "0 Q ~ "" ~

Co (,J Co ~ ~ ~

'Q . ";F. 1i = Q 

### :' ~ ~ .

.... .... "" '

~ Q 

### ~ ~ 

## - ;,

rI:J Co 

## ~ t - ~



## r. rI:J ~ 5 g, ~ ....

(,J rI:J (,J

rI:J

rI:J
tII) ~ ~



### "0 (,J .- =

.:J 0 == ....

0 ~ ~ ~

(,J ~ .... ~ ~ "" ~ 

### ~ .-

S ~ ,Q ;::: == ""

rI:J U :i 

# 00 ...



### "0 '" =.... j;; .s V 

### rI:J ~ -= '" 

# ~ ~

0 5 

### ;;; .... "'.- 

### ~'g ~~ 

# ~ ~ ~~

# Conclusion

Planned future work includes monitoring most or all of these 19 sites again in 1998. Two consecutive years of data collection should provide an indication of trends in water flow patterns , excessive debris and siltation problems , bypass outfall conditions and more. Also in 1998 , nets will be set behind screens during early evaluations (early May and late June) to capture juvenile salmonids soon after hatching, when they are smallest and most likely to be entrained. These screen evaluations are valuable because they provide information that can substantiate the effectiveness of screen operations and maintenance practices for protecting fish. Water velocity measurements and underwater video evaluations also expose areas of concern or potential problems that routine maintenance does not typically reveal. Also , in the case of new or modified screen sites where operating procedures have not been refined , detailed evaluations can pinpoint areas where the procedures may 

### need to be altered. For example , where operating procedures are in place and being followed but approach velocity, bypass flow , or other parameters do not fall within 

### NMFS criteria, evaluations will identifY the problem areas and alert screen operators 

### that the reasons for noncompliance should be investigated. For example , actual canal 

### water usage might be examined to confirm that irrigators are not drawing more water 

### than they are allowed. If all possibilities have been explored and no reasons for the problems are found then operating criteria should be modified to meet NMFS criteria 

### and to protect fish. An ideal fish screening program combines routine operations and maintenance with a monitoring program to evaluate the effectiveness of these practices at protecting fish at individual screen sites. By including water velocity and underwater video evaluations in the process , the greatest protection will be provided for fish.

# Methods
Nineteen operating screen sites in the Yakima, Naches, and Tieton River basins were evaluated between April 30 and August 22 , 1997 (Figure 1).



### ~~"

r--....