Washington Administrative Code
Title 220 - Fish and Wildlife, Department of
ENVIRONMENTAL STANDARDS AND CONSERVATION
Chapter 220-660 - Hydraulic code rules
Section 220-660-200 - Fish passage improvement structures
Universal Citation: WA Admin Code 220-660-200
Current through Register Vol. 24-18, September 15, 2024
The provisions in this section apply to fish ladders, weirs constructed for fish passage management, roughened channels, trap-and-haul operations, and hydraulic design culvert retrofits.
(1) Description: Fish passage improvement structures facilitate the passage of fish through or around a barrier. They restore upstream and downstream fish access to habitats that have become isolated by human activities such as placing culverts, dams, and other artificial obstructions.
(2) Fish life concerns: Barriers can block fish from using upstream spawning and rearing habitat. The main goal is to remove fish passage barriers and ensure unimpeded passage of fish at all life stages, as well as to maintain natural channel processes and function. However, when it is not feasible to remove a barrier, a fish passage improvement structure may be an alternative mitigation measure. The department does not generally recommend using fish passage improvement structures because they can be partial barriers to fish passage and generally require maintenance. Fish passage improvement structures that mainly pass one species or class of fish may unintentionally limit the passage of other species.
(3) Fish passage improvement structure design:
(a) Fish passage improvement structures
should not be used to bypass permanent natural barriers except in limited
situations where they are needed to restore native fish species.
(b) A person must provide site and biological
information relevant to the specific project, such as information on species
present, hydrology and topography, and existing adjacent structures.
(c) The department may require compensatory
mitigation if a fish passage structure cannot pass all fish species present at
all mobile life stages.
(d) The
design must consider site-specific conditions that could affect the function of
the fish passage improvement structure. These include meander migration or
vertical change in stream bed elevation, debris and bedload movement,
tampering, vandalism, and poaching.
(e) The fish passage structure design must
withstand the maximum expected flow.
(f) The fish passage structure must not
result in significant migratory delays as determined by the department or
mortality to fish life due to disorientation, distraction, predation, stress,
or injury.
(g) The fish passage
structure must accommodate expected run sizes to prevent crowding and
significant delay of fish migration as determined by the department.
(h) The department will determine the
inspection interval depending on the type of fish passage improvement structure
and watershed conditions.
(i) The
department may require the installation of a temporary fish passage structure
to provide passage through temporary obstructions. The department may not
require a fish passage structure if a barrier exists for such short duration
that the department determines that no lasting impacts to fish life will
occur.
(4) Temporary fish passage improvement structures design:
(a) A person must maintain a fish passage
structure in an effective condition. If the structure starts to hinder fish
passage, the person must obtain an HPA and promptly repair the
problem.
(b) The department may
approve the installation of temporary fish passage improvement structures when
permanent structures are damaged or are under construction, to conduct
maintenance or repair, for enhancement projects, or for seasonal water
diversion structures such as irrigation diversion dams.
(c) Temporary fish passage improvement
structures must remain operational for the duration of the temporary
obstruction and must be maintained and adjusted as needed to provide efficient
passage of fish life.
(5) Fish ladder design:
(a) The department may authorize a fish
ladder if:
(i) The fish ladder will enable
fish passage at an existing barrier, but only until the existing barrier
structure is replaced; or
(ii) The
department determines that constructing a bridge, culvert, or roughened channel
is not feasible due to the nature of the obstruction such as a flow control
structure or the slope of the stream.
(b) The fish ladder design must be
appropriate for the slope of the channel, water surface elevations, species
present, flow regime, and conditions of the channel.
(c) The fish ladder must be designed to
prevent fish from leaping out of the structure.
(d) The fish ladder pool volume must provide
the hydraulic and fish capacity needed to pass all adult and juvenile
fish.
(e) The fish ladder entrance
(downstream end):
(i) Must provide enough
streaming flow attraction during high and low flows, without excessive velocity
or turbulence, to ensure fish can locate and enter the fish ladder without
significant delay;
(ii) Must
minimize distractions that lure fish away from the entrance to prevent fish
from becoming trapped, injured, or stranded;
(iii) Must be large enough to accommodate all
expected debris and ice without damage or loss of passage efficiency;
(iv) Must provide a stable flow pattern and
uniform velocity at the entrance pools and transition channels to allow fish to
pass through the structure unimpeded;
(v) Must provide multiple entrances to the
fish ladder if a single entrance cannot attract and provide passage to all
adult and juvenile fish. If the work area has multiple zones where fish
accumulate, each zone must have at least one entrance; and
(vi) May be required to have artificial light
to optimize fish passage.
(f) Fish ladder auxiliary water supply system
(AWS):
(i) To ensure fish are attracted to
the fish ladder, an AWS may be required that supplies supplementary
water.
(ii) An AWS must have a
diffuser design that discourages attraction of fish life to it and protects
fish from injury.
(iii) An AWS must
minimize the size of spaces between the diffuser to exclude and prevent injury
to the smallest fish present.
(iv)
An AWS must not use an auxiliary water supply from external sources that could
confuse the homing instinct of fish.
(g) To prevent harm to fish life, the
department may require screening of the AWS.
(h) The department may require a trash rack
at the AWS intake.
(i) Fish ladder
exits must:
(i) Have a water depth that is
similar to the depth inside the fish ladder;
(ii) Be located to ensure fish can safely
exit the structure without susceptibility to predators, without becoming
disoriented, and with the ability to continue their upstream migration;
and
(iii) Be designed to protect
the exit from damage by debris.
(6) Fish ladder construction: To reduce potential contact injuries, all edges and surfaces exposed to fish must be ground smooth to the touch, with all edges aligning in a single smooth plane.
(7) Fish ladder operation and maintenance:
(a) If
target fish species are present and actively migrating, fish ladders with AWS
must have enough water available at all stream flows to pass fish safely and
efficiently through the fish ladder or the main channel without the need of a
fish ladder.
(b) A person must
inspect the fish ladder for proper function at a frequency determined by the
department. Place wood and sediment retrieved during inspection and maintenance
downstream of the fish ladder.
(c)
A person operating or maintaining the fish ladder must be able to identify
maintenance issues with the fish ladder and take corrective actions or notify
the department if maintenance issues arise.
(d) The department may require shutdown of
the fish ladder during high flows if the flow exceeds the fish passage design
flow. However, a fish ladder must not be inoperable due to high flows for
longer than seven days during the migration period for the target fish species.
This provision applies to locations where the shutdown will not cause flooding
or damage to structures, other structures of value or property.
(8) Fish passage weir design:
(a) Design the weir to control
the water surface elevation at the weir to provide fish passage over or through
an obstruction.
(b) Design the weir
to minimize impacts to natural channel geometry.
(c) Design the weir to ensure continued fish
passage for all species present at all mobile life stages. The department may
approve exceptions when it is implementing a program to restore native fish
species or to protect native fish species from the introduction of nonnative
fish species, and fish passage blockage is an intended component of the
project.
(9) Roughened channel design:
(a)
The department may authorize a person to construct a roughened channel to
facilitate the passage of fish around abrupt hydraulic drops, through culverts,
or at diversion sites for water withdrawal.
(b) Roughened channels must be designed by
licensed professional engineers, geomorphologists, or other qualified
professionals approved by the department.
(c) Where nonleaping fish are present or when
other types of fish passage improvement structures would not pass fish well
enough as determined by the department, a person may be required to construct a
roughened channel to bypass an obstruction.
(d) Roughened channels must create an average
cross-section velocity within the limits of fish-passage design criteria and
the hydraulic design option.
(e)
Roughened channels must minimize impact on the existing fish life and habitat
that supports fish life.
(f) The
size and gradation of roughened channel bed material must resist erosion at the
maximum expected flow and must result in a dense structure that prevents
subsurface flow.
(10) Trap-and-haul operations:
(a)
The department requires an HPA for installing, maintaining, and removing fish
traps for trap-and-haul activities.
(b) The fish trap must be designed to
withstand the maximum expected flow.
(c) The fish trap must be operated in a
manner that prevents crowding and delaying target fish species migration as
determined by the department.
(11) Hydraulic design culvert fish passage design:
(a) The department may
authorize an existing hydraulic design culvert to remain in place until the end
of its design life or until another more appropriate culvert design can be
constructed. However, a hydraulic design culvert cannot remain in place to the
end of its design life if it does not provide for passage of fish.
(b) Before obtaining a permit to retrofit a
culvert or construct a fish passage improvement structure using the hydraulic
design method, a person must submit appropriate hydrology data and hydraulic
design documentation prepared by a licensed professional engineer that
demonstrates compliance with this section.
(c) The hydraulic design fish passage
structure must include consideration of flood capacity for current conditions
and future changes likely to occur within the stream channel, and debris and
bedload passage.
(d) Plans
submitted to the department to retrofit a culvert or to construct a fish
passage improvement structure using the hydraulic design method must comply
with the following:
(i) Minimum water depth
at any location within a hydraulic design passage structure without a natural
bed must be at least eight-tenths of a foot. The minimum depth of flow in the
passage structure is determined by:
(A) The
low flow design, which is the two-year seven-day low flow discharge for the
subject basin; or
(B) When flow
information for the site is unavailable, the department may authorize the use
of calibrated flows from a comparable gauged site or the depth of the culvert
when no water is flowing.
(ii) Maximum water velocity may not exceed
the values in Table 1 at any point within a culvert. Measure maximum water
velocity at the high fish passage design flow.
Table 2
Maximum Velocity Design Criteria for Hydraulic Design
Culvert Installation
| Culvert Length | Maximum Velocity |
| 10 - 100 ft. | 4.0 feet per second |
| 100 - 200 ft. | 3.0 feet per second |
| > 200 ft. | 2.0 feet per second |
(e) The hydraulic drop within the culvert or
at the culvert inlet or outlet may not exceed one-half foot. When a drop has a
submerged jet (the lowest part is below the downstream water surface) or is
part of a natural or roughened channel design, the department may approve an
exception to this drop limit.
(f)
Water turbulence within the culvert must not be a barrier to passage of target
fish species.
(g) The department
may modify or approve design flow criteria for specific proposals as needed to
address unusual fish passage requirements.
Disclaimer: These regulations may not be the most recent version. Washington may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
This site is protected by reCAPTCHA and the Google
Privacy Policy and
Terms of Service apply.
