BPA Fish and Wildlife FY 1997 Proposal

Section 1. Administrative
Section 2. Narrative
Section 3. Budget

see CBFWA and BPA funding recommendations

Section 1. Administrative

Title of project
Evaluation of Spill Efficiency

BPA project number   5515900

Business name of agency, institution or organization requesting funding

Sponsor type   Placeholder

Proposal contact person or principal investigator
 Mailing address

BPA technical contact   ,

Biological opinion ID   Research M&E Program; Hypothesis B.2.

NWPPC Program number   

Short description
This project would assess spill efficiency through hydroacoustics, radio-tracking, and other methods across a range of hydraulic and operational conditions and fish species. Information on spill efficiency (i.e., the proportion of juvenile migrants passing through spill relative to the proportion of total river discharge passing through spill) is needed to better understand how spill contributes to avoiding turbine-related mortality. An improved understanding of spill efficiency would also enhance planned operations relative to the target of 80% fish passage efficiency (FPE) and dissolved gas supersaturation constraints.

Project start year   1996    End year   

Start of operation and/or maintenance   0

Project development phase   PLANNING

Section 2. Narrative

Related projects

Project history

Biological results achieved

Annual reports and technical papers

Management implications
Provides validated information on spill efficiency for establishing appropriate spill levels to achieve the Biological Opinionís 80% FPE target. May result in determination that at some dams, under certain conditions, the 80% FPE target is achieved without exceeding state dissolved gas supersaturation standards. When coupled with information on passage survival through various routes of passage, will enhance understanding of project passage survival, and therefore, provide improved information for dam operational strategies for fish passage.
Water management decisions are based on assumed movements of smolts; improved empirical information is needed to support these assumptions to ensure a sound basis for water management decisions.

Specific measureable objectives

Testable hypothesis
B.2.7. Smolts do not pass dams in spill flows in proportion to spill fraction of river discharge.

Underlying assumptions or critical constraints
Requires a range of conditions, and operational flexibility to assess the range of conditions, to determine spill efficiency over time for different salmonid stocks and species.


Brief schedule of activities

Biological need
Generally, smolts are presumed to move across the dam through turbine or spill flows in proprotion to the fractions of water passing those routes; however some work indicates that fish do not move in proportion to routed flows. Also, radio tracking at Lower Granite suggests that spring/summer chinook may not respond rapidly to spill flows, but remain in the forebay for extended periods. Descriptive information is needed to better balance the use of spill to enhance juvenile fish survival, particularly given concerns relative to dissolved gas supersaturation and gas bubble disease as well as adult passage concerns. Spill efficiency should be evaluated at all dams where spill is a major mitigation tool, and over a range of river discharges. Priorities would include Lower Granite, Bonneville, The Dalles, John Day, and McNary.

Critical uncertainties

Summary of expected outcome
Spill efficiency passage curves across a range of spill conditions and river discharge levels.

Dependencies/opportunities for cooperation
May require reassessment following installation of gas abatement or surface collection structures.


Monitoring activity
Determination of spill efficiency would be based on several methodologies, including radio-tracking and hydroacoustics.

Section 3. Budget

Data shown are the total of expense and capital obligations by fiscal year. Obligations for any given year may not equal actual expenditures or accruals within the year, due to carryover, pre-funding, capitalization and difference between operating year and BPA fiscal year.

Historic costsFY 1996 budget data*Current and future funding needs
(none) New project - no FY96 data available 1997: 500,000

* 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.

Funding recommendations

CBFWA funding review group   System Policy

Recommendation    Tier 2 - fund when funds available

Recommended funding level   $500,000