i.3

E 

INTERBGENCY ECOLOGICAL STUTlY PROeRAN 

FOR THE SACRAMENTO-SA??JOAQUIN ESTUARY 

DELTA FISH FACILITIES TECHNICAL COORDINATING COMMITTEE 

WORKING JUSTIFICATION PAPER NO. 2 

"Justification For Eliminating From Further 

Consideration The Horizontal Rotary Drum 

Screen For The Peripheral Canal" 

August 1979 
JUSTIFICATION FOR ELIMINATING FROM FURTHER 

CONSIDERATION THE HORIZONTAL ROTARY DRUM 

SCREEN FOR TISE PERIPHERAL CAN&/ 

This is a %orking justification paper" that presents the rationale for the present direction of the Delta Fish Facilities Program,

It was prepared by the Delta Fish Facilities Technical Coordinating

Comaittee whose members include both biological and engineering

staff of the Interagency Ecological Study Program for the Sacramento-San Joaquirn Estuary,. As a "working" document it is subject 

to change based on new fhdings, policy redirection, time, financial and other constraints. 

This paper recomiends that further work on conventional horizontal 

rotary drum screens be eliminated from the program, This decision 

is based on a literature review and the results of evaluations of 

two existing horizontal rotary drum screen installations, the GlennCofusa Irrigation District fish screen near Hamilton City and the 

Woodbridge Irrigation District fish screen near Woodbridge, California * 

E 

-I/ Prepared by the Delta Fish Facilities Technical Coordinating ComExittee, part of the Interagency Ecological Study Program for the 

Sacramento-San Joaquin Estuary whose members *include: California 

Eepartrnent of Fish and Game, California Department of Water Resources, U. s. Bureau of Reclamation, and U. s, Fish and Wildlife 

Service. 
-2-

DISCUSSION 

The horizontal rotary drum screen has been under consideration for 

the inzake of the Peripheral Canal. Originally developed in 1921 

By the Oregcn Garne Commission it has seen considerable use throughaut the West, Clay (1961) summarizes some basic information and 

applications for this screen concept, 

The. horizontal rotary drum screen has proven a reliable device for 

screening fish once certain basic criteria have been met. These criteria include a relatively constant water surface elevation which 

$eaves the upper half to one-third of the drum height exposed, appropriate mesh size eo prevent the loss of fish, and effective seals at 

the bottom and sides of the drum screen (Figure 1). 

Our evaluations have indicated that a solution to the second criterion is available, while a solution to the third could be developed

wirhin existing time, financial, and technological constraints. However, the difficulty and cost of satisfying the first criterion 

listed limits the applicability of the horizontal drum and makes it 

less desirable than fixed screen or a vertical drum screen. 

The water surface of the Sacramento River at Hood vazies from about 

8 to i-6 m (0 to +20 ft) USC and GS Datum, with the screen base located at -5 rn (-16 ft). Unless protected by floodgates, a drum screen 

wor;'Hd be subjected to the full range of water surface variations. To 

satisfy the first criterion, 2:he drum screen could either be on the 

order of 15 m (50 ft) in diameter, move up and down with river stage, 

ox the water level would have to be controlled with floodgates in 

front of the screen. The difficulty of designing, constructing, and 

malneaining a drum screen approximately 15 m (50 ft) in diameter 

eliEinates this alternative. The difficulty and anticigated cost 

of developing, constructing, 2nd operating a "floatable horizontal 

drsx screen also makes it less desirable than a fixed screen or a 

vertical drrrm screen. The operation of floodgates in front of the 

screen to control water level at the screen would accelerate flow 

velocities through the control structure, tending to "pull in" toward 

the screens fish with limited swiming ability. This would happen

with either the on-river or off-river alternatives, and is undesirable, 

A conclusion that horizontal rotary drum screens are inappropriate 

'~.irasalso reached by John E. Skinner, in his review titled "Peripheral

Canal, Fish Facilities Program; 1973-74 Evaluations and Decisions,"

dated August 2, 1974. That document was prepared at the request of 

the Fish Facilities Consulting Board to document the status of the 

program at that time, 

CONCLUSION 

We recommend deleting the horizontal rotary drum screen conce t from 

further consideration for the Peripheral Canal, based primariPy on: 
L 

cn 

.I 

I

a

41 w /

c/) 

1 

43 
-3-

I, (1) the size-related problems of a horfzontal rotary drum screen, 

(2) the difficulty and high cost of developing and operating a 

‘‘floatabfe” horizontal rotary drum screen, and (3) the undesirability of controlling ehe water surface elevation at the fish screen 

wit11 a floodgate structure constructed in front of the fish screen, 

or at the inzake of an off-river channel. 
-4-

LITERATURE CITED 

clay, C. H. 2.961, Design of fishways and other fish facilities. 

Queen's &inter, Ottawa. 301 pp. 

i