Current through Register 2024 Notice Reg. No. 38, September 20, 2024
1.
STRUCTURE PLACEMENT
A.
Streams And Rivers (flowing
water): The screen face shall be parallel to the flow and adjacent
bankline (water's edge), with the screen face at or streamward of a line
defined by the annual low-flow water's edge.
The upstream and downstream transitions to the screen
structure shall be designed and constructed to match the back-line, minimizing
eddies upstream of, in front of and downstream of, the screen.
Where feasible, this "on-stream" fish screen structure
placement is preferred by the California Department of Fish and
Game.
B.
In Canals
(flowing water): The screen structure shall be located as close to the
river source as practical, in an effort to minimize the approach channel length
and the fish return bypass length. This "in canal" fish screen location shall
only be used where an "on-stream" screen design is not feasible. This situation
is most common at existing diversion dams with headgate structures.
The National Marine Fisheries Service -- Southwest Region
"Fish Screening Criteria for Anadromous Salmonids, January 1997" for these
types of installations shall be used.
C.
Small Pumped Diversions:
Small pumped diversions (less than 40 cubic-feet per second) which are screened
using "manufactured, self-contained" screens shall conform to the National
Marine Fisheries Service -- Southwest Region "Fish Screening Criteria for
Anadromous Salmonids, January 1997".
D.
Non-Flowing Waters (tidal areas,
lakes and reservoirs): The preferred location for the diversion intake
structure shall be offshore, in deep water, to minimize fish contact with the
diversion. Other configurations will be considered as exceptions to the
screening criteria as described in Section 5.F. below.
2.
APPROACH VELOCITY (Local velocity
component perpendicular to the screen face
A.
Flow Uniformity: The design
of the screen shall distribute the approach velocity uniformly across the face
of the screen. Provisions shall be made in the design of the screen to allow
for adjustment of flow patterns. The intent is to ensure uniform flow
distribution through the entire face of the screen as it is constructed and
operated.
B.
Self-Cleaning
Screens: The design approach velocity shall not exceed:
1. Streams And Rivers (flowing waters) --
Either:
a. 0.33 feet per second, where
exposure to the fish screen shall not exceed fifteen minutes, or
b. 0.40 feet per second, for small (less than
40 cubic-feet per second) pumped diversions using "manufactured,
self-contained" screens.
2. In Canals (flowing waters) -- 0.40 feet
per second, with a bypass entrance located every one-minute of travel time
along the screen face.
3.
Non-Flowing Waters (tidal areas, lakes and reservoirs) -- The specific screen
approach velocity shall be determined for each installation, based on the
species and life stage of fish being protected. Velocities which exceed those
described above will require a variance to these criteria (see Section 5.F.
below).
(Note: At this time, the U.S. Fish and Wildlife Service has
selected a 0.2 feet per second approach velocity for use in waters where the
Delta smelt is found. Thus, fish screens in the Sacramento-San Joaquin Estuary
should use this criterion for design purposes.)
C.
Screens Which Are Not
Self-Cleaning: The screens shall be designed with an approach velocity
one-fourth that outlined in Section B. above. The screen shall be cleaned
before the approach velocity exceeds the criteria described in Section
B.
D.
Frequency Of
Cleaning: Fish screens shall be cleaned as frequently as necessary to
prevent flow impedance and violation of the approach velocity criteria. A
cleaning cycle once every 5 minutes is deemed to meet this standard.
E.
Screen Area Calculation: The
required wetted screen area (square feet), excluding the area affected by
structural components, is calculated by dividing the
maximum diverted flow (cubic-feet per
second) by the allowable approach velocity (feet per second). Example:,
1.0 cubic-feet per second / 0.33 feet per second =
3.0 square feet
Unless otherwise specifically agreed to, this calculation
shall be done at the minimum stream
stage.
3.
SWEEPING VELOCITY (Velocity component parallel to screen face)
A.
In Streams And Rivers: The
sweeping velocity should be at least two times the allowable approach
velocity.
B.
In
Canals: The sweeping velocity shall exceed the allowable approach
velocity. Experience has shown that sweeping velocities of 2.0 feet per second
(or greater) are preferable.
C.
Design Considerations: Screen faces shall be designed flush with
any adjacent screen bay piers or walls, to allow an unimpeded flow of water
parallel to the screen face.
4.
SCREEN OPENINGS
A.
Porosity: The screen surface
shall have a minimum open area of 27 percent. We recommend the maximum possible
open area consistent with the availability of appropriate material, and
structural design considerations.
The use of open areas less than 40 percent shall include
consideration of increasing the screen surface area, to reduce slot velocities,
assisting in both fish protection and screen cleaning.
B.
Round Openings: Round
openings in the screening shall not exceed 3.96mm (5/32in). In waters where
steelhead rainbow trout fry are present, this dimension shall not exceed 2.38mm
(3/32in).
C.
Square
Openings: Square openings in screening shall not exceed 3.96mm (5/32in)
measured diagonally. In waters where steelhead rainbow trout fry are present,
this dimension shall not exceed 2.38mm (3/32in) measured diagonally.
D.
Slotted Openings: Slotted
openings shall not exceed 2.38mm (3/32in) in width. In waters where steelhead
rainbow trout fry are present, this dimension shall not exceed 1.75mm
(0.0689in).
5.
SCREEN CONSTRUCTION
A.
Material Selection: Screens may be constructed of any rigid
material, perforated, woven, or slotted that provides water passage while
physically excluding fish. The largest possible screen open area which is
consistent with other project requirements should be used. Reducing the screen
slot velocity is desirable both to protect fish and to ease cleaning
requirements. Care should be taken to avoid the use of materials with sharp
edges or projections which could harm fish.
B.
Corrosion And Fouling
Protection: Stainless steel or other corrosion-resistant material is the
screen material recommended to reduce clogging due to corrosion. The use of
both active and passive corrosion protection systems should be considered.
Consideration should be given to anti-fouling material
choices, to reduce biological fouling problems. Care should be taken not to use
materials deemed deleterious to fish and other wildlife.
C.
Project Review And Approval:
Plans and design calculations, which show that all the applicable screening
criteria have been met, shall be provided to the Department before written
approval can be granted by the appropriate Regional Manager.
The approval shall be documented in writing to the project
sponsor, with copies to both the Deputy Director, Habitat Conservation Division
and the Deputy Director, Wildlife and Inland Fisheries Division. Such approval
may include a requirement for post-construction evaluation, monitoring and
reporting.
D.
Assurances: All fish screens constructed after the effective date
of these criteria shall be designed and constructed to satisfy the current
criteria. Owners of existing screens, approved by the Department prior to the
effective date of these criteria, shall not be required to upgrade their
facilities to satisfy the current criteria unless:
1. The controlling screen components
deteriorate and require replacement (i.e., change the opening size or opening
orientation when the screen panels or rotary drum screen coverings need
replacing),
2. Relocation,
modification or reconstruction (i.e., a change of screen alignment or an
increase in the intake size to satisfy diversion requirements) of the intake
facilities, or
3. The owner
proposes to increase the rate of diversion which would result in violation of
the criteria without additional modifications.
E.
Supplemental Criteria:
Supplemental criteria may be issued by the Department for a project, to
accommodate new fish screening technology or to address species-specific or
site-specific circumstances.
F.
Variances: Written variances to these criteria may be granted with
the approval of the appropriate Regional Manager and concurrence from both the
Deputy Director, Habitat Conservation Division and the Deputy Director,
Wildlife and Inland Fisheries Division. At a minimum, the rationale for the
variance must be described and justified in the request.
Evaluation and monitoring may be required as a condition of
any variance, to ensure that the requested variance does not result in a
reduced level of protection for the aquatic resources.
It is the responsibility of the project sponsor to obtain
the appropriate fish screen criteria as provided herein. Project sponsors
should contact the Department of Fish and Game, the National Marine Fisheries
Service (for projects in marine and anadromous waters) and the U.S. Fish and
Wildlife Service (for projects in anadromous and fresh waters) for
guidance.
Copies of the criteria are available from the Department of
Fish and Game through the appropriate Regional office, which should be the
first point of contact for any fish screening project.
Northern California and North Coast Region; 601 Locust
Street, Redding, CA 96001 -- (530) 225-2300.
Sacramento Valley and Central Sierra Region; 1701 Nimbus
Drive, Rancho Cordova, CA 95670 -- (916) 358-2900.
Central Coast Region; 7329 Silverado Trail/P.O. Box 46,
Yountville, CA 94599 -- (707) 944-5500.
San Joaquin Valley-Southern Sierra Region; 1234 E. Shaw
Avenue, Fresno, CA 93710 -- (209) 243-4005.
South Coast Region; 4649 View Crest Avenue, San Diego, CA
92123 -- (619) 467-4201.
Eastern Sierra and Inland Deserts Region; 4775 Bird Farms
Road, Chino Hills, CA 91709 -- (909) 597-9823. Marine Region; 20 Lower Ragsdale
Drive, #100, Monterey, CA 93940 -- (831) 649-2870. Technical assistance can be
obtained directly from the Habitat Conservation Division; 1416 Ninth Street,
Sacramento, CA 95814 -- (916) 653-1070.
The National Marine Fisheries Service -- Southwest Region
"Fish Screening Criteria for Anadromous Salmonids, January 1997" are also
available from their Southwest Region; 777 Sonoma Avenue, Room 325, Santa Rosa,
CA 95402 -- (707) 575-6050.
