BPA Fish and Wildlife FY 1997 Proposal
Section 1. Administrative
Section 2. Narrative
Section 3. Budget
see CBFWA and BPA funding recommendations
Title of project
Skipanon Tide Gate Retrofit
BPA project number 5519800
Business name of agency, institution or organization requesting funding
Skipanon Water Control District
Sponsor type OR-State/Local Agency
Proposal contact person or principal investigator
|Mailing address||Jim Scheller
523 Turlay Rd.
Warrenton, OR 97146
BPA technical contact ,
Biological opinion ID
NWPPC Program number
Tide gate modification on the Skipanon River in Warrenton at the Eighth Street Dam to restore fish passage.
Project start year 1997 End year 1997
Start of operation and/or maintenance 1998
Project development phase Implementation
Biological results achieved
Annual reports and technical papers
Specific measureable objectives
A better functioning tide gate which allows for seasonal manipulation of water flow will support:
· Increased passage of salmon through the gate (Measurements will consider variability in ocean survival by comparing return counts to those on other streams in the regions.)
· Reduction of sedimentation above the gate
· Reduction in the growth of invasive, exotic fresh water plant species above the gate
Low or negligible return rates of salmon released from the Warrenton High School fish hatchery, located above the tide gate on the Skipanon river, are in part due to the obstacle imposed by the tide gate installed in 1961. Returns will increase if the obstacle is reduced or removed.
Return counts conducted by the Oregon Department of Fish and Wildlife (ODF&W) in the early 90’s estimated a return of only 12 -14 fish above the dam. No counts have been conducted since. Cullaby Creek in the upper Skipanon system, however, has been classified as essential indigenous anadromous salmon habitat by ODF&W, to be included in riparian zones protected by Oregon Administrative Rules 141-102-000 through 141-102-100. Restoring fish passage through the Eighth Street Dam tide gate will provide access to the essential habitat for wild fish runs, if they still exist, and support the continued efforts of the High School hatchery program.
Underlying assumptions or critical constraints
Parent stock can be provided by the Warrenton High School hatchery program with expectations of a one to two percent return rate below the dam.
The past use of dams, dikes and channelization along with forestry, fishing and agricultural practices, have contributed to the critical degradation of this Skipanon water watershed. It is recognized that several habitat and water quality issues need to be addressed concurrently with fish passage issues. Continued community support for restoration of the Skipanon watershed and its salmon run is assumed.
Design elements for a retrofit to the Eighth Street Dam tide gate considered the following objectives and constraints:
· Allow for the manual operation of the gates to significantly increase the opportunity for fish passage
· Reduce the upstream accumulation of silt (11 - 12 feet behind flash boards installed in the existing structure) to pre-construction levels by providing a mechanism for controlled scouring of the river bottom
· Ability to maintain the flood control function of the structure
· Work with the existing structure to minimize expense of retrofit
The City Engineer for Warrenton, with consultation from Waterman Industries Incorporated, designed a two stage tide gate system which would achieve the above objectives. Modifications would be made to one of the three bays of the existing structure. A 60” X 48” stop gate would be installed which could be held open during times of low threat from tidal flooding. A slide gate would be installed using existing gate guides near the upstream end of the bay which would maintain control of water flow. The slide gate would be adjusted as the existing flash boards on the upstream side of the dam are removed, allowing for controlled scouring of sediment deposits and the maintenance of reasonable water levels. For more detailed information on the operation of the proposed system contact George Hall, City Engineer, Warrenton 503-861-0917. Design drawings can be provided on request.
Brief schedule of activities
October 96 - June’ 97
· Apply for necessary permits
· Order materials
· Schedule assistance in instillation from City of Warrenton or private contractor
June 97 - September ‘97
· Installation of new tide gate to be completed during the in-water work window specified by ODF&W for the Skipanon
(1997 fiscal year funding is requested for materials and installation. )
September 97 - September 2001
· Ongoing monitoring of fish returns, sediment levels above the dam, temperature and presence of exotic plant species
(1998- 2001 fiscal rear funding is requested for follow up monitoring.)
ODF&W salmon surveys from the 50’s counted hundreds of fish in a single day. Since construction of the Eighth Street Dam salmon have suffered a severe decline in number. ( Two other smaller dams have also been constructed, but provide for adequate fish passage.) Sedimentation due to reduced water flow has resulted in other habitat degradation. Culllaby Lake and the lower Skipanon have been listed as water quality limited by the Department of Environmental Quality with pollutants cited as: exotic weeds, sedimentation, and low dissolved oxygen. The High School fish hatchery monitoring efforts have noted increases in water temperature and declines in benthic organisms up stream of the Eighth Street Dam. Passage and flow restrictions resulting from the existing tide gate contribute to these water quality and habitat limitations. The remaining habitat resources on the Skipanon, along with an active fish hatchery program and the concerned citizenry provide an opportunity for restoring a valuable salmon run.
The spawning success of the resident wild salmon for the past several years is unknown. The remaining population may be too small to recover despite our best efforts.
Summary of expected outcome
An increased return of salmon past the Eighth Street Dam would be a significant step in restoring the wild salmon run in the Skipanon. It would also serve to bolster the efforts of the High School hatchery program, which is poised to provide the next best alternative if in fact the wild run does not survive in the watershed.
Retrofitting the Eighth Street Dam and improving fish passage will also serve as inspiration to residents of the watershed and Warrenton as a whole in their growing effort to restore the water quality and beneficial uses of the Skipanon.
Dependencies/opportunities for cooperation
The possibility of the coastal coho salmon being listed as a threatened or endangered species has resulted in the mobilization of many interest groups to define efforts for restoring salmon populations. The use of retrofits to mitigate for salmon decline resulting from the wide use of tide gates in the lower Columbia estuary and elsewhere where on the coast is a relatively new effort. The Eighth Street Dam project provides a unique opportunity to demonstrate the benefits of improved tide gate technology since the hatchery releases a documented quantity of ocean going smolt from above the gate.
The risks of watershed destruction and loss of biodiversity are related to the status quo. Doing nothing is our greatest risk.
Monitoring of the project’s outcomes will be conducted by Warrenton High School with oversight by the Department of Environmental Quality. Monitoring will assess the following parameters:
· Fish return above the dam for both wild and hatchery fish
· Change in sediment levels and stream bed depth above the dam
· Temperature and dissolved oxygen levels between the dam and the hatchery
· Salinity levels up to Cullaby lake
· Presence of exotic, fresh water, plant species up to Cullaby Lake
|Historic costs||FY 1996 budget data*||Current and future funding needs|
|(none)||New project - no FY96 data available||1997: 95,000|
* For most projects, Authorized is the amount recommended by CBFWA and the Council. Planned is amount currently allocated. Contracted is the amount obligated to date of printout.
CBFWA funding review group Below Bonneville Dam
Recommendation Tier 2 - fund when funds available
Recommended funding level $95,000