Long Range Plan for the Klamath River Basin Conservation
Area Fishery Restoration Program
Part 1 of
ISSUES
* The ability of instream work to correct fish
habitat degradation is limited, unless the underlying watershed
problems that cause degradation are also addressed.
* Must detailed habitat analysis necessarily precede investments
in habitat restoration?
* Who should pay for the watershed restoration, streamflow augmentation
and erosion control efforts necessary to protect and restore fish
habitat?
* The need to work with ranchers to restore riparian zones to
prevent erosion from destroying pasture land and to improve
fish habitat.
* The need to improve streamflows, particularly in the Shasta
and Scott river valleys, in ways that do not disrupt ranching.
* The need to gain a better understanding of the Klamath Basin
through the use of aerial photography, Landsat imagery and other
available technical resources.
INTRODUCTION
This chapter describes the methods that have
been used in attempts to restore the fisheries habitat of the
Klamath River Basin and the degree of success such attempts have
enjoyed. Suggestions regarding appropriate means to approach habitat
restoration during the balance of the Klamath River Basin Fisheries
Restoration Program are made.
We must quit looking at just a pool, a riffle,
or even a reach, but address the problem as it fits into a complete
watershed. How often have we visited a good looking K-dam, stream
deflector, or rock crib to enhance a small reach, only to look
around the watershed and see it crumbling down upon us.
W.S. Platts
Bill Platts made these remarks at a 1984 habitat
management workshop (Hassler 1984) that would prove to be a turning
point in the use of instream structures for improving degraded
fish habitat. Instream structures enjoyed a surge in popularity
in the 1930's, largely for erosion control in the Midwest (Silcox
1936, Tarzwell 1938). As early as 1934, the California Department
of Fish and Game (Burghduff 1934) acknowledged that stream improvement
involving "retardation of stream flow by the construction
of weirs and erosion dams ... do not fit existing conditions in
most of our western streams, which are precipitous, rock-bound,
and fall thousands of feet in a score of miles."
Despite the recognition that these instream structures
did not work for most of California's streams, the Civilian Conservation
Corps built them throughout the Great Depression. After evaluating
these efforts, Calhoun (1966) concluded that attempts to treat
California streams with instream structures had "no instances
of reasonable success."
Taft and Shapovalov (1935) surveyed many of the
streams of the Klamath Basin and found that, for the most part,
they provided "fine pools for shelter, trees and brush for
shade and to furnish terrestrial food, and many riffles to provide
abundant food and spawning areas. Thus they do not seem to call
for 'stream improvement' in the accepted meaning of the term."
Noted exceptions were several diversion dams without ladders and
"hanging" road culverts which blocked fish migration.
While the stream habitat conditions found by Taft and Shapovalov
may have been much different than those of today, theirs is still
a valid prescription for improvement: "From the viewpoint
of fish life, the most important improvement that could be effected
in streams would be the general restoration to natural conditions."
Many of the stream channels of the Klamath River
Basin are so disturbed today their complete restoration could
well take longer than the life of the Restoration Program. Every
increment of well planned habitat improvement will help, therefore,
in the rebuilding of the region's fish populations. Moreover,
while early restoration efforts suffered from a poor understanding
of the factors that limit salmonid fish production, including
inadequate knowledge of stream dynamics (Everest and Sedell 1984),
renewed public interest in stream restoration has fostered a substantial
increase in our abilities.
Bisson et al. (1981) and, more recently, McCain
et al. (in press) have developed systems for classifying the types
of fish habitat in streams. As habitat use by salmonids is noted,
fisheries biologists have been able to focus more closely on the
factors which limit the production of salmon and steelhead. Although
habitat typing by itself does not provide a complete understanding
of limiting factors, further work by Reeves et al. (1989) has
provided a key which can be used to identify stream production
bottlenecks for juvenile coho salmon. Hankin and Reeves (1988)
have developed methods for estimating basin-wide salmonid populations
in tributaries, based on the number of fish which use different
habitats and the number of habitat units found in the stream.
While fisheries science has been exploring the
habitat elements that limit salmon and steelhead production, the
use of instream structures to mimic these elements has been widely
tested throughout the Pacific Northwest (Anderson 1988). The compatibility
of different treatments is now checked against stream gradient,
streambed stability, height of flood flows and other critical
data to assure that the structure will remain in place, at least
during moderate storm events, and will function as intended. Studies
of undisturbed stream systems have improved the design criteria
for habitat restoration projects significantly (Sedell and Luchessa
1981).
Some of the best habitat restoration information has come from
the study of geomorphology and hydrology. While fisheries managers
have long been able to recognize degraded fish habitat, geologic
information now provides insight into the root causes of that
degradation (Hagans et al. 1986). In addition, knowledge of geology
can help to determine the stage of recovery of a stream (Lisle
1981), whether an oversupply of sediment is likely to continue,
and whether attempts to structurally manipulate a stream are prudent
(Lisle and Overton 1988). Prioritizing erosion prevention in this
way can help reduce the amount of sediment likely to reach the
stream (Weaver and Hagans 1990). As watersheds are stabilized,
the recovery of stream channels will be accelerated.
It has been a challenging task to evaluate instream
structures to determine their cost-effectiveness (Everest and
Sedell 1984). While the costs of projects are easy to determine,
the number of fish which they produce can be difficult to establish
(Fontaine 1988). Arriving at a value for the fish produced by
a project can also be a complex process (Meyer 1980).
Methods of improving or restoring fish habitat,
in addition to those involving channel and bank stabilization,
include the removal of barriers to migration, screening stream
diversions to reduce the loss of both juvenile and adult fish,
increasing stream flows, replacing gravel, creating spawning or
rearing channels below dams, and restoring riparian vegetation.
Public interest and support for salmon, steelhead,
and trout restoration have grown rapidly in the past decade. Community
groups in California have become an integral part of restoration,
both for fund-raising and for carrying out projects. While volunteer
effort lends the obvious advantage of enabling projects at low
cost, it serves even more importantly to create a grass-roots,
or community-level, commitment to fish conservation. Many of the
state's restoration groups are associated with the California
Salmon, Steelhead and Trout Restoration Federation, which holds
annual meetings to share technical information and the restoration
spirit. The Oregon Salmon and Trout Enhancement Program (STEP)
has also been highly successful as a catalyst for involving the
public in fish restoration. STEP projects have included instream
structures, hatch boxes, rearing ponds, and education programs.
Although the art of fisheries restoration has
advanced considerably in recent years, some still question whether
structural manipulation of anadromous fish habitat is an effective
strategy for increasing production of these fish (Nawa 1987).
It is generally understood that instream structures are no substitute
for good watershed stewardship, including the protection of productive
fish habitat (Anderson 1988, Everest and Sedell 1984, Reeves and
Roelofs 1982). Improving fish habitat through watershed restoration
takes years, while instream structures can offer habitat improvement
much quicker. In an ideal situation, structures would be used
to accelerate habitat recovery after watershed stabilization is
well underway. The Task Force may be required, however, to use
instream structures for immediate habitat improvements to benefit
those fish stocks identified in Chapter 4 as priorities for recovery.
HABITAT RESTORATION METHODS
Fisheries habitat improvements can involve four
general areas: instream work, riparian area restoration, streamflow
improvement and watershed stabilization.
Improving Access to Spawning Areas
Barriers to fish migration have long been identified
as impediments to anadromous fish production and fishways have
been constructed for 200 years or more. The sophistication of
fish passage facilities benefitted from research associated with
construction of dams on the Columbia and Snake rivers (Savage
1986). Fish ladders that bypass dams can be a series of simple
jump pools or elaborate systems involving elevators (Bell 1973).
Passage over natural barriers or short, steep impediments like
culverts, use vertical slots with baffles to slow the flow and
allow upstream migration (Clay 1961). The most common vertical
slot type fishways are the Alaska steep pass and the Denil ladder
(Ziemer 1962). A common objective of all fishway designs is a
good attraction flow and an easy entrance for the fish.
Figure 3-1 -- Before installation of an Alaska
steep pass, this culvert was a barrier, at low flows, to salmon
and steelhead trying to reach their spawning grounds.
Heavy equipment has been used on mid-Klamath
tributaries to modify sediment plugs near stream mouths that create
fish migration barriers (J. West personal communication). Other
barrier modifications have included log jam removal and blasting
of rock barriers. Recent work by Sedell et al. (1988) indicates
that, in our haste to provide fish passage, we may have removed
large woody material that provided essential habitat elements.
Fish Screens Reduce the Loss of Juveniles
Fish screens are used to prevent juvenile salmonids
from being drawn into agricultural diversions. These devices range
from huge drum screens that block passage into major California
irrigation canals to simpler devices to keep downstream migrants
out of small ditches leading to pastures. Recent designs provide
for the screens to be self-cleaning to prevent them from becoming
clogged with algae or floating debris.
Figure 3-2 -- Fish screens, such as this one
along Shackleford Creek, a Scott River tributary, save thousands
of young salmonids from being diverted into the fields.
Improving Fish Habitat With Instream Structures
Improvement of spawning conditions has been a
major focus of instream habitat efforts. Gabions, log weirs, boulder
weirs and other structures have been used successfully to trap
spawning gravels (House 1984). Rearing habitat can be created
for juvenile salmonids by providing cover and causing pools to
form by the use of drop structures or by placing boulders, logs,
or large root wads to cause scouring (Anderson 1988). Pools can
also be created by blasting. These techniques are typically used
in streams that have suffered degradation and that lack habitat
complexity.
Streamflow Improvements Add Spawning and Rearing
Habitat
Both spawning and rearing habitat can be increased
by increasing flows below dams or diversions. Iron Gate Dam was
constructed to reduce fluctuations in flows caused by upstream
hydroelectric operations. The fluctuations caused stranding of
adult salmon and steelhead and heavy mortality of juveniles. Claire
Engle and Lewiston Dams on the Trinity River were completed in
1964 and divert over 80% of the river's flow into the Central
Valley for agricultural use. Flows in the Trinity River have been
improved over pre-1980 levels in order to study their benefit
to fisheries resources (Hampton 1988). The U.S. Forest Service
has worked to retain instream flows in order to maintain river
channels through National Forest Lands in Colorado (Randolph 1990).
Channel maintenance flows have emerged as an issue on the Trinity
River (Bob Franklin personal communication). The periodic relicensing
of major dams by the Federal Energy Regulatory Commission provides
the opportunity to negotiate improvements in flows for fish (Echiverra
1989). Opportunities for increasing streamflows for fish through
water conservation measures are being explored in Oregon, California,
and Montana (see Chapter 2).
Special Restoration Techniques Appropriate
Below Dams
To the extent that dams stabilize flows in the
stream reaches below them, they make structural treatments in
those reaches more practical. Smaller gravels and cobbles suitable
for spawning are washed downstream below dams, however, and the
recruitment of replacement gravel is prevented by the dams. Severe
loss of the quality and quantity of pre-dam spawning habitat frequently
occurs. To counteract such loss, new spawning gravels have been
trucked to stream reaches below dams. The absence of flushing
flows cause gravels to become so impacted with silt that they
become unsuitable for spawning. Heavy equipment has been used
extensively to loosen silted spawning gravels in Washington state
(Savage 1986). Pools have been dredged below Grass Valley Creek
on the Trinity River to provide holding areas for adult spring
chinook (USFWS in press).
Side channels can be added below dams for spawning
and rearing as the dams make high flows less likely. The concentrations
of fish returning to hatcheries built below dams uses the stream
habitat improvements made at these sites.
Restoring Riparian Areas Can Yield Big Dividends
The vegetated areas next to streams provide bank
stability, cover for fish, habitat for birds and animals, shade
to keep water temperatures cool, terrestrial insects for fish
to eat, leaf litter which fuels the aquatic food chain, and recruitment
of logs which provide instream structure. Riparian vegetation
also traps fine sediment and organic matter during high flows,
thereby helping to build banks (Platts 1984a). Elmore (1988) has
found that a healthy riparian zone acts as a conduit for recharging
ground water.
Where livestock grazing has decreased riparian
vegetation, streamside areas can be fenced and grasses, shrubs
and trees replanted. The stabilization of streambanks with riprap,
gabions, or log revetments can prevent bank erosion but may not
provide optimal fish habitat unless done in conjunction with riparian
planting. Riparian zones in forested streams can also be replanted
but if sediment supply remains high, channel instability can make
it difficult for trees and shrubs to become reestablished. Natural
regrowth of conifers can take over one hundred years after severe
flooding or logging in stream side areas (Lisle 1981).
Watershed Rehabilitation: Helping Nature Restore
Fish Habitat
Watershed restoration to benefit fish resources
would begin with an inventory and evaluation of sediment sources,
the changes in sediment supply likely to result from storms or
changes in land use, and the relative magnitude of the different
sediment sources (Weaver and Hagans 1990). From this basic information
a sediment budget can be formulated and priorities for treatment
established. Treatments may include attempts to stabilize a slide
by revegetating it, armoring the toe of a streamside landslide,
putting roads "to bed," removing or enlarging culverts,
outsloping roads or installing waterbars, dewatering slides, mulching
and planting bare slopes, and a host of similar measures (Mattole
Restoration Council 1989).
Figure 3-3 -- Riparian restoration improves fish
habitat dramatically.
Top: Stream before treatment. Middle: After installation
of boulder weirs, at a higher flow. Bottom: Streamside replanting
beginning to mature.
While erosion prevention work may seem costly,
it is much less expensive than the removal of sediment from stream
channels after it has left the hillsides. The investment in instream
structures and riparian restoration efforts may be ineffective
if a high rate of sediment continues due to erosion in upslope
areas. Natural processes created fish habitat, and if watersheds
are restored and protected by improved land use practices, good
fish habitat will return. Watershed measures may take longer to
dramatically alter specific sites within streams, but once implemented
their benefits are long-lasting and will enable the stream to
restore itself over its entire length, not just in treated reaches.
CHOOSING APPROPRIATE FISHERIES RESTORATION
STRATEGIES
Before effective action can be taken to restore
fish populations, project planners should have enough information
to determine which factors are limiting the production of the
species to be restored (Everest and Sedell 1984). Only then can
they determine accurately which treatments to use. Some limiting
factors may be obvious, such as diversion of the entire flow of
a stream during spawning or outmigration seasons. If substantial
numbers of juvenile salmonids are being lost to irrigation, then
installing fish screens is clearly logical, but when considering
the use of instream structures to increase specific habitat elements,
a much closer look at limiting factors is needed. Habitat needs
should be determined on a basin-wide, or subbasin wide, scope
and should include both biological and physical habitat assessments
(Reeves 1988).
Using Fish Abundance To Determine Restoration
Needs
The presence or absence of anadromous fish above
a perceived barrier obviously can indicate whether barrier modification
or construction of a fish pass is needed. Using fish populations
to assess the need for habitat restoration measures can as easily
be misleading, however. Low fish numbers can result from harvest
or poor access, in low water years, of spawning migrations. For
this reason, it is desirable to have estimates of fish numbers
for several years. Spawner counts, electrofishing, and direct
observation are three established means of estimating fish numbers.
The number of salmon spawners can be estimated
by counting carcasses or salmon redds. As carcasses are counted
they are marked with a tag or cut in half. Subsequent counts use
the ratio of marked to unmarked carcasses to estimate the total
number of spawners. Steelhead are much more wary than salmon while
spawning, do not always die after reproduction and cannot, therefore,
be counted in this way.
Electrofishing is also used to estimate fish
numbers. The stream reach is blocked with nets and the fish in
the area are stunned with electricity and counted. Several passes
may be made to collect as many of the fish within the section
as possible, and statistical methods are used then to determine
the total number of fish present (Platts et al. 1983). In a small
or medium sized stream, electrofishing can give a very accurate
assessment of fish populations in the area sampled. Extrapolating
these results to estimate basin population totals can lead to
significant errors (Everest et al. 1986). Hankin (1986) asserted
that errors in population estimates for basins resulted more from
expanding data from small stream segments than from the accuracy
of the counts within the segments themselves. He suggested conducting
population estimates by habitat units, and not on arbitrary lengths
of stream, can help reduce this error.
When water clarity is good and stream depth is
sufficient, direct observation by divers is the best method for
determining populations of salmonids over a basin-wide area (Hankin
and Reeves 1988). The numbers of fish are related to the habitat
types in which they are counted. Expansions are based on the total
number and area of habitat types in the basin. Visual estimation
is much quicker than electroshocking, so more stream area can
be counted by direct observation and the errors associated with
extrapolation can be reduced. To check the validity of these counts
or to estimate the degree of bias, a subsample of habitat units
where fish were counted by direct observation can be electroshocked
and the numbers compared.
Figure 3-4 -- Divers with masks and snorkels
estimate fish populations by direct observation.
Physical Factors Determine Restoration Techniques
If a stream appears in need of rehabilitation,
the first level of assessment should include an historical search
to determine when changes may have occurred, what caused the changes
(e.g., logging followed by a large flood event), and whether the
watershed in question still contains major sources of sediment.
The use of aerial photos is a quick and cost-efficient way to
study changes over time (Grant 1988) and to assess current watershed
conditions (Weaver and Hagans 1990). If significant sediment sources
still exist in a basin, then instream structures are not a prudent
investment because it is likely they will soon be buried or rendered
dysfunctional (Lisle and Overton 1988). Erosion prevention measures
and, where necessary, changes in land use practices should be
pursued first.
If the watershed under study no longer has significant
erosion problems, the next step would be an attempt to determine
the current stage of stream channel recovery (Lisle 1981). If
the streambed has become aggraded it may be unstable and untreatable
until it approaches its former elevation (Lisle and Overton 1988).
Rosgen's channel typing (1985) system can be
used in this stage of analysis to help determine whether particular
reaches are compatible with particular treatments. Lisle and Overton
(1988) suggest that structures to retain spawning gravel should
not be placed in stream reaches having a gradient of less than
0.25 percent nor greater than 1 percent. Any stream having a gradient
greater than 2 percent (Lisle and Overton 1988) or 2.5 percent
(Anderson 1988) is generally unsuitable for instream structures
due to the force of water during high flows. All instream work
should take into account the hydraulic forces which occur at flood
stages and the expected interval at which potentially destructive
flows might occur.
After the larger questions of whether the watershed
and stream bed are suited to structural treatment, an in-depth
fish habitat survey can be conducted (Bisson et al. 1981 and McCain
et al in press). Hampton (1989) suggests that, as a first step,
the freshwater life stages of each target species, and their respective
habitat requirements, should be understood. In this way, the relative
abundance of habitats may indicate what is limiting the production
of the species of interest (Hampton 1988). Knowledge of the adjacent
streams would be helpful since preferred habitats may be lacking
altogether. Habitat typing is generally conducted at low summer
flows, leading to the frequent conclusion that rearing habitat
at these flows is the limiting factor. Increasing the amount of
such habitat might not increase smolts production, however, if
a more important problem is winter survival (Mason 1976, Hampton
1988). Thus, even where restoration projects are undertaken after
habitat typing and limiting factor analysis, such projects should
be evaluated to see if they were, in fact, the solution to low
fish abundance.
Other important questions regarding habitat that
should be addressed before structural treatments are pursued are
those of water quality and quantity. It makes little sense to
structurally treat a stream where water quality will not support
fish life. Water can be tested for temperature, dissolved oxygen,
or pollutants (American Public Health Assoc. 1987).
THE EFFECTIVENESS OF PREVIOUS HABITAT
RESTORATION EFFORTS
A Task Force compilation of projects undertaken
to improve fish conditions in the Klamath River Basin, including
the Trinity River, (USFWS 1988b) indicates that $7.8 million has
been spent on such efforts since 1958. Funds for these projects
have come from the U.S. Soil Conservation Service, California
Department of Fish and Game, U.S. Forest Service, U.S. Bureau
of Indian Affairs, Hoopa Valley Tribal Council, California Conservation
Corps, Pacific Power and Light Co. and the U.S. Bureau of Reclamation.
Since 1984 there has been a significant increase
in fisheries restoration activity in the Klamath Basin. Substantial
amounts of funds for fish restoration have been provided directly
by legislation, as well as by voter initiatives. The 1984 Trinity
River Restoration Program (P.L. 98-541) and the 1986 Klamath River
Basin Fisheries Restoration Act (P.L. 99-552) have specifically
committed the U.S. Department of Interior to fisheries restoration
efforts in the Klamath-Trinity basins. Congress has expanded the
U.S. Forest Service's role in fisheries conservation in recent
years (P.L. 93-452, P.L. 94-588), as well.
The Task Force's planning consultants, William
M. Kier Associates, inspected nearly two-thirds of the projects
listed in the 1988 compilation during the summer and fall of 1989.
Their observations, which are summarized in Appendix C, concerned
only the physical integrity of structures and their apparent success
in creating their intended stream conditions. There was not sufficient
opportunity to determine the success of the structures in producing
fish, or their cost-effectiveness. The following discussion draws
heavily on the 1989 field review, although some examples from
other areas are discussed as well.
Success In Improving Access For Migrating
Fish
The Klamath Basin projects to provide fish access
past migration barriers have, for the most part, been successful.
Many projects conducted by the California Conservation Corps (CCC)
in the lower basin have involved modifying log jams to allow migration.
Unlike earlier efforts that totally removed jammed logs, the CCC
now leaves much of the material in the channel to act as cover
or to form natural structures. Hewitt ramps were installed on
Ah Pah Creek, and appear successful in passing fish. A baffle
installed by the Redwood Community Action Agency on a Richardson
Creek culvert eliminated what was a velocity barrier to coho and
chinook salmon.
On Tarup Creek, the CCC improved fish passage
by blasting a bedrock waterfall believed to block chinook salmon
migration. Similar methods were used to open up five miles of
Dillon Creek to both salmon and steelhead. Low cost projects that
open areas in a highly productive streams like Dillon Creek are
excellent investments in restoration. Opening Bluff Creek to salmon
and steelhead, after access was blocked by the 1964 flood, represents
a major success in fisheries restoration. Blasting opened three
miles of habitat on Clear Creek and log jam removal on its South
Fork opened an additional one and a half miles of habitat to summer
steelhead, as well as other runs of salmon and steelhead (D. Maria
personal communication).
Several successful barrier modifications in the
Salmon River Basin have been carried out, including projects on
Black Bear Creek, St. Claire Creek, and Knownothing Creek. A rock
fall which blocked chinook salmon migration in the main stem of
the Salmon River was altered. Chinook and coho salmon numbers
doubled in Knownothing Creek after treatment. A step and pool
ladder was constructed on Nordheimer Creek, a tributary to the
Salmon River. The ladder, located one and a half miles above the
mouth of the creek, helps fish travel over a 14-foot-high bedrock
falls and opened up three miles of additional habitat to anadromous
fish. A large number of adult steelhead climbed the ladder in
1988, the first year it was available (D. Maria, personal communication).
Barrier modification on Kelly Gulch in the Salmon River failed
to assist chinook salmon passage, but improved access for migrating
steelhead.
Additional habitat in Indian Creek has been made
available by the removal of several obstructions to migration.
Four ladders have been constructed on the Shasta River and they
function. Access to Independence Creek was blocked until the mouth
of the stream was altered. Steelhead are now seen entering this
system in the fall before major winter flows (J. West personal
communication). A fish pass on Coon Creek works at some flows,
but requires ongoing maintenance.
Fish Screens, Rescue Efforts Save Juvenile
Salmon and Steelhead
The California Department of Fish and Game's
Yreka fisheries staff devotes a considerable amount of effort
to keeping juvenile salmonids out of irrigation diversions. The
Scott and Shasta rivers and their tributaries require much of
this work, but several small mainstem Klamath tributaries, including
Bogus Creek, Cottonwood Creek, Little Bogus Creek, Cold Creek,
and Dry Creek are also important fish screen and rescue work areas.
Screens are installed at ditch intakes to prevent
the juvenile fish migrating downstream from being drawn into the
fields. Downstream migrant traps are placed above dewatered stream
segments. Fish rescue operations at screens and traps save about
450,000 juvenile salmonids a year. Huntington (1988) found that
fish screening and rescue efforts were very cost effective. He
estimated a cost-benefit ratio of 3.1/1 for screening operations.
Problems at screens can arise from lack of maintenance, and screens
are sometimes removed or not installed when needed (D. Sumner
personal communication). An additional worker has been added to
Fish and Game's Yreka office to help keep up with the increasing
screen operation and maintenance needs (R. Dotson personal communication).
New screens are planned for Bogus and Cold creeks
which will complete the screening of stream diversions in the
entire Bogus Creek watershed. Four additional screens are needed
in the Kidder Creek drainage and will be installed over the next
two years. Another priority is a main diversion ditch in the West
Fork of the Scott River. Screen priorities are based on the potential
loss of fish at each diversion site. There are currently 56 screens
in the area served by the Fish and Game's Yreka staff (R. Dotson
personal communication).
Mixed Results From Instream Habitat Structures
Instream structures to increase spawning and
rearing habitat for juvenile salmonids generally use materials
available at the site, typically logs and boulders. While the
majority of the structures surveyed in 1989 appeared to be functioning
as intended, many were partially or totally disabled.
Boulder clusters on the South Fork of the Salmon
have attracted spawning chinook salmon and steelhead and also
provided rearing habitat (West 1984). Approximately 20 percent
of the boulder clusters examined had caused bank erosion. Log
weirs in St. Claire Creek were functioning well, while others
in steeper tributaries of the Salmon River had been washed out
by high flows.
Boulder clusters in Knownothing Creek had been
lost to high flows. Log weirs failed in Nordheimer Creek and 25
percent of the boulder groups on Blind Horse Creek, intended to
trap spawning gravel, trapped silt instead.
Figure 3-5 -- These boulder weirs on the South
Fork of the Salmon River have attracted spawning chinook salmon
and steelhead, and also provide rearing habitat.
Boulder weirs and clusters constructed on Red
Cap Creek were in place and had created the desired improvements
in habitat. They were reported to be providing juvenile habitat
and attracting spawners (J. Boberg personal communication). Camp
Creek boulder weirs failed as a result of the February 1986 storm.
They have been replaced with new boulder clusters which appear
to be functioning well. The Bluff Creek boulder clusters were
working well, although a major slide, reactivated in February
1986, had filled the spaces around some of them.
Intense rainfall during a thunderstorm in August
1989 unleashed a debris flow that buried recently installed boulder
groups on Beaver Creek. Other boulder clusters in the same drainage
required cleaning with a suction dredge because of sedimentation
(S. Fox personal communication). Boulders used for structures
on Irving Creek were too small, and the intended benefit was not
derived. Irving Creek also has an aggraded delta that appears
to be a migration barrier during low flows. High flows have broken
apart boulder clusters in Humbug Creek. Access problems for spawners
also exist in this tributary.
Attempts to increase spawning habitat in Cottonwood
Creek with blast pools did not work. High flows pushed gravels
through some of the pockets and decomposed granite sands settled
in others. The pools did, however, provide some rearing habitat.
The gravel supply in Cottonwood Creek has been diminished by gravel
extraction for road construction (D. Sumner personal communication).
Boulder weirs in the Shasta River had been damaged by high flows
and were only partially fulfilling their intended function of
trapping spawning gravel.
Projects on Hunter Creek and Tarup Creek were
well constructed. The planning for these CDFG/CCC projects used
a method of triangulation known as the "two pin method."
The work crews found instructions to be very clear and they were
successful in carrying out the plans as designed. Although the
quality of work was high, large sediment deposits near the stream
mouths still limit access to spawners and the downstream migration
of juveniles in both creeks. Hunter Creek flows underground for
over three miles in its lower reaches during summer as a result
of an oversupply of sediment.
In disturbed watersheds in southern Oregon, with
slopes and geology similar to the lower Klamath tributaries, 95
percent of the instream structures installed prior to the February
1986 storm were no longer functioning as designed when examined
(Frissel and Nawa 1988). Structural treatments in the highly aggraded
systems in the lower Klamath have not yet been tested by a major
storm.
A spawning channel constructed in Bluff Creek
has been used by chinook salmon and steelhead (J. Boberg personal
communication). Both coho salmon and steelhead were observed using
the spawning channel in Indian Creek (D. Maria personal communication).
Spawning channels on the main stem of the Klamath River at Tree
of Heaven and Badger Flat are not functioning as intended. Inadequate
water depth in the Tree of Heaven prevented its use by salmon
and steelhead spawners. Heavy flows at the Badger Flat riffle
blew out rock weirs and spawning gravels. The Pacific Power and
Light Co. added spawning gravels to the river below Iron Gate
Dam in 1964 but they were washed down river by a flood later that
year (M. Coots personal communication.)
Increasing Streamflows To Benefit Fish
In 1981, U.S. Secretary of the Interior, then
Cecil Andrus, ordered that flow releases to the Trinity River
from the U.S. Bureau of Reclamation's Trinity River Project be
tripled to improve fishery conditions in the river and that a
twelve-year study be conducted by the U.S. Fish and Wildlife Service
to determine precisely how much water should be committed permanently
to the conservation of the river's fish resources (Hampton 1988).
While the Trinity fisheries streamflow study
is still underway, the improved flows appear to be responsible
for the increased returns of adult salmon and steelhead to the
upper Trinity River (USFWS in press). The improved flows have
decreased summer stream temperatures below the dam to desired
levels. The USFWS team has documented increases in the amount
of chinook salmon rearing habitat, considered to be the limiting
factor for natural chinook salmon production in the area. Even
higher flows than those ordered by Secretary Andrus appear needed
if the river's salmon rearing habitat potential is to be fully
realized (Bob Franklin personal communication). Higher flows may
also be required in the future for channel maintenance, to flush
silt and sand, unless Congress wishes to supply an annual budget
for maintaining channel conditions artificially by dredging and
gravel ripping. Increased flows may be an important key to the
successful downstream migration of fish released from the Trinity
River Hatchery, that is, to improve their survival and decrease
their impact upon native juvenile salmonids (USFWS in press).
Habitat Improvements Below Trinity Dam Largely
Successful
Eight side channels were built along the main
stem of the Trinity River below Trinity Dam, primarily to increase
juvenile salmonid rearing habitat. Five of the eight channels
have been evaluated and all are being used by large numbers of
juveniles (USFWS in press). These side channels have withstood
flows of 2,000 cubic feet per second without major damage. Gravel
has been removed from the mouth of Rush Creek and deposited in
riffle areas upstream to increase spawning areas. Large numbers
of adult salmon and steelhead have used these riffles in the two
years since the gravel was placed there (USFWS in press). Most
of the gravels remained in place during the 2,000 cfs flows in
1989.
Bucktail and Cemetery pools were dredged in the
Trinity in 1989 to provide additional holding habitat for adult
chinook salmon. While an evaluation of this pool increase has
not been made yet, the high mortality of spring chinook in 1988
was thought to be related to the overcrowding of fish in the holding
areas available that summer (USFWS in press).
Mechanical ripping to remove fine sediments from
spawning gravels has not been a success on the Trinity. Ripping
has, in fact, caused the fine sediments to become more firmly
settled in the substrate and has churned up substrate unsuitable
for spawning (USFWS in press).
The Fishery Benefits of Riparian Enhancement
Projects
Many bank stabilization and erosion control projects
involving large boulders have been carried out along the riparian
zone of the Scott River. Patterson (1976) found that scouring
next to these structures had increased the depth of the adjacent
pools and created more habitat for salmonids. While salmonids
were, indeed, more plentiful, they were far outnumbered by suckers
and dace. Many of these stabilized areas were left unfenced, riparian
vegetation was not replanted, and grazing continues along the
streambanks. If vegetation were allowed to grow back it would
create cover, provide shade, and improve salmonid habitat.
Banks have been stabilized with boulders on Red
Cap Creek and riparian vegetation reestablished with natural seedings.
Ah Pah Creek fisheries habitat improvement work by the CCC included
use of gabion baskets to armor the toe of streamside landslides.
When the CCC blew up a rock falls that was a migration barrier
on Tarup Creek, rock fragments were used to armor a nearby landslide.
Eastern Oregon streams, in areas similar to the
upper Klamath Basin, recovered very well when riparian areas were
planted and cattle kept out of most of the streamside zone (Elmore
1988). Even streams that had been so severely overgrazed that
they flowed underground have had both their surface flows and
fish life restored. Similar treatments in Wyoming resulted in
tremendous increases in native trout populations (Binns 1986).
Platts (1982) notes other studies where restricted grazing in
riparian areas has allowed the recovery of streams in Idaho and
Great Basin areas.
Watershed Stabilization: Some Successes, Lots
of Potential
The U.S. Forest Service has an ongoing program
of erosion control involving such practices as reforestation and
road maintenance. Following the 1987 fires large scale erosion
control efforts included mulching disturbed areas, such as fire
lines, seeding vast areas with grasses, and constructing numerous
check dams to control erosion in the draws above streams. Two
basins were constructed on Hotelling Gulch and Olsen Creek to
catch sediment before it enters the Salmon River. The trapped
sediments will be removed after storms. These traps have been
filled to capacity even by storms of moderate intensity. An experimental
sediment trap was installed by the Forest Service on French Creek,
a tributary to the Scott River. The lack of an on-site sediment
storage area made the continued removal of sediment at this site
too expensive, so the structure is no longer in use. Increased
sedimentation in French Creek did not result from fire-related
watershed damage, but from road cuts and disturbances related
to timber harvest (Sommarstrom 1990).
Figure 3-6 -- Putting roads "to bed"
in Hoopa Reservation watersheds has reduced erosion and helped
streams to recover.
The USFS has begun erosion control efforts in
Grouse Creek, a tributary to the South Fork of the Trinity River.
Because high sediment loads stemming from timber harvest and related
roads in this mixed ownership watershed have led to fish habitat
degradation, the Six Rivers National Forest has ceased timber
harvest on USFS lands in the basin. Studies have been conducted
to determine the most effective means to revegetate and stabilize
the hillslopes (Matthews et al. 1990) and a sediment budget has
been formulated (Kelsey et al. 1989). An Environmental Impact
Statement is being prepared to determine how much erosion control
work will have to be done before timber harvest on USFS lands
may resume.
The USFWS Trinity River Program Office has been
moving toward a watershed approach to fisheries restoration for
the Trinity River Fish and Wildlife Management Program (USFWS
in press). Efforts initially focused on the Grass Valley Creek
watershed, where the Trinity River Program has built a large sediment-trapping
dam. Work has now expanded to include the entire Trinity watershed,
including its South Fork, where monumental erosion problems exist
(CDWR 1982). The potential of each stream to produce fish, together
with its relative contribution of sediment to the main Trinity
River, has become the basis for determining Trinity Program project
priorities. Those projects that will be accompanied by changes
in land use to lessen future erosion problems will be given top
priority.
The CCC has accomplished several erosion control
projects in the lower Klamath River tributaries. Their work on
Salt and Tarup Creeks included the installation of waterbars on
abandoned roads near streams. Three failed road crossings on Salt
Creek were also treated. A streamside landslide on Ah Pah Creek
was stabilized by replanting vegetation.
Some of the most extensive watershed restoration
work in the Klamath Basin has been undertaken by the Hoopa Valley
Tribal Council's Fisheries Department. When instream structures
failed due to sediment problems, watershed stabilization programs
were begun. Undersized culverts on logging roads have been replaced,
trash racks installed on culverts, and a maintenance program to
keep these racks free of debris has been initiated. Where feasible,
abandoned logging roads and landings have been graded back to
the slope of the hill, mulched and seeded. Streams have been deflected
away from the toes of landslides and gabion baskets and riprap
used to help stabilize these features. The Hoopa Valley Tribe
has also begun a study on Pine Creek to identify the sources of
sediment and to prioritize the measures needed to decrease sediment
production.
An ambitious and comprehensive watershed approach
to fisheries restoration is underway in the watershed of the Mattole
River, a coastal stream downcoast of Humboldt Bay, through the
efforts of the Mattole Restoration Council. A recent study, Elements
of Recovery (MRC 1989), identifies the major sources of sediment
throughout the Mattole watershed. The calculation of a sediment
budget was beyond the scope of the project, but treatments were
prioritized and rehabilitation prescriptions made in the study.
Another successful watershed program is that
on the South Fork of the Salmon River in Idaho. Large amounts
of decomposed granite sand had entered the river due to extensive
logging, which was followed by floods. Improved land use, the
replanting of hillslopes and putting roads to bed significantly
reduced the amount of fine sediments in the river's spawning gravels
(Platts and Megahan 1975).
KRIS Klamath Resource Information System