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
Hydraulics in Snake River Reservoirs

BPA project number   5500600

Business name of agency, institution or organization requesting funding
U.S. Department of Energy

Sponsor type   TN-Federal Agency

Proposal contact person or principal investigator

BPA technical contact   Dan Daley, EWI 503/230-3066

Biological opinion ID   Numbers 4, 10, 13g

NWPPC Program number   

Short description
The study will quantify distances in Snake R. reservoirs that would have unsteady & turbulent flow hydraulics (stage waves, bursts, vortices that may assist migration of juvenile salmonids) at different elevations, flow rates, & non-steady-state dam ops.

Project start year   1997    End year   1998

Start of operation and/or maintenance   0

Project development phase   Implementation

Section 2. Narrative

Related projects
None that we are aware of that relate unsteady, turbulent flows to
fish migration needs.

Project history

Biological results achieved

Annual reports and technical papers

Management implications

Specific measureable objectives
To develop estimates of the channel lengths in the upstream
portions of four sequential Snake River reservoirs that would be
characterized by unsteady and turbulent flow hydraulics (believed to be used by juvenile salmonids to aid migration) at a series of river flow rates, reservoir elevations, and non-steady-state operations of dam releases. These channel lengths will be used to evaluate alternative flow and elevation measures for aiding downstream migrations of juvenile salmonids through the reservoirs.

Testable hypothesis
It is hypothesized that higher river flow rates, lower reservoir
elevations, and non-steady-state operations of dams (together or
separately) can act to increase the channel length of the upstream portion
of a reservoir (tailwater of an upstream dam) that is essentially
river-like, and characterized by turbulent, unsteady flow hydraulics
believed to be important for fish migration. The proposed study would test
the hypothesis and quantify the relationships for the four Snake River
reservoirs.

Underlying assumptions or critical constraints
Unsteady, turbulent flows are characteristic of natural rivers in
which downstream migrations of juvenile salmonids evolved. It is believed
that juvenile salmonids use hydraulic features of such flows (e.g., stage
waves, turbulent bursts, vortices) as aids in maximizing downstream
migration rate and distance per unit of energy expended by a fish. Thus,
reservoir management for maximal unsteady and turbulent flow hydraulics may
be more biologically appropriate for aiding migration success than
management for flow volume or velocity. Although it is logical to
hypothesize that the upstream reach of unsteady, turbulent flow in a
mainstem reservoir would be longer with higher river flow rates, lower
reservoir elevations, and changing operations at the dams, this has not
been demonstrated either empirically or mathematically for the Snake River
reservoirs. For practical management using hydraulics to aid fish
migrations, the actual relationships need to be quantified.

Methods
The study would first consist of a mathematical evaluation of flow
hydraulics in Snake River reservoirs. Features of channel bathymetry such
as channel width, bottom profiles, slope, bottom roughness, and depth
(which differ with reservoir elevations) can be used with river flows and
steady or unsteady dam operations to estimate channel hydraulics. It is
expected that much of the physiographic information can be obtained from
the U. S. Army Corps of Engineers, whose cooperation and assistance with
the project will be essential. Hydraulic models would be run at several
river flow rates and elevations of Lower Granite, Little Goose, Lower
Monumental, and Ice Harbor reservoirs. Distances (river kilometers) with
unsteady or turbulent flow would be compared for different flow and
elevation conditions, and mathematical descriptions of the relationships
would be provided for each reservoir. River flows and reservoir elevations
to be evaluated would be indexed to the performance capability and recent
history of the river system, as well as to management options (such as flow
augmentation and reservoir drawdowns) already under consideration. In a
second year of effort, the results would be extended to additional
considerations of alternative dam operations (steady or pulsed) and
structural modifications of the reservoirs that might increase unsteady,
turbulent flows for the benefit of fish. A second year might also be
needed to obtain physical data on the river-reservoir system that are not
currently available, so that hydraulic estimates can be refined.

Brief schedule of activities
October-December 1996: Collection of existing physiographic
(bathymetric) information on the river-reservoir channel in the lower Snake
River mainstem, with help of collaborators (especially USACE).
January-July 1997: Model runs and estimates.
August-September 1997: Summarization of first-year modeling
results, preparation of progress report, and development of research plan
for FY 1998.
FY 1998: Collection of needed physiographic data, extension of
analyses to additional management options, integration of results with
biological data; preparation of final project summary report and manuscript
for open literature publication.

Biological need
The ISG's review of science behind the Fish and Wildlife Program has
uncovered strong evidence that juvenile salmonids use unsteady and
turbulent flow characteristics (e.g., stage waves, turbulent bursts,
vortices) as aids in maximizing downstream migration rate and distance per
unit of energy expended by a fish. Assuming this to be true (although the
weight of biological evidence would be aided by verification studies),
reservoir management for maximal unsteady, turbulent flow hydraulics
typical of rivers may be more biologically appropriate for aiding migration
success than management for flow volume or velocity (the main factors
considered today). In principle, lowering reservoir elevations and
increasing river flows would each result in a lengthening of the reach of
upper reservoir where river-like flow hydraulics occur. Non-steady-state
operation of dams undoubtedly induces unsteady flows. There is a need,
therefore, to quantitatively estimate the lengths of river-reservoir
reaches that would have unsteady and turbulent flows (for assisting the
biological behaviors associated with successful fish migrations) at
alternative flow rates, reservoir elevations, and dam operations.

Critical uncertainties
The critical uncertainty is the amount of river-reservoir channel
in the lower Snake River that could be returned to a state of more
river-like unsteady, turbulent flow under different river flows, reservoir
elevations, and dam operations, especially those under consideration for
flow augmentation and reservoir drawdown. How much increase there would be
in conditions favorable to successful fish migration with different flow
and elevation options is uncertain when the variable of concern to fish may
be the amount and distribution of unsteady, turbulent flow. Although one
clear uncertainty is the degree to which fish depend on such flow
hydraulics, the more tractable study of river-reservoir hydraulics can
better define the management opportunities before detailed fish behavior
studies would be undertaken.

Summary of expected outcome
The study would quantify the length of reservoirs in the lower
Snake River that would have unsteady and turbulent flows, which are
favorable to fish migration behavior, under a range of river flow rates,
reservoir elevations, and dam operations. This quantification should be
valuable for evaluating management options for aiding juvenile salmonid
outmigrations with minimum impact on other waterway uses.

Dependencies/opportunities for cooperation
This work would require the assistance and cooperation of the USACE
in detailed project planning and in obtaining physiographic-bathymetric
data for the Lower Snake River reservoirs. Some new physiographic data may
be necessary for confident hydraulic estimates, and these would need to be
obtained by a field crew onsite coordinated by the USACE.

Risks
There should be no risks to either humans or fish from this
mathematical, hydrodynamic study.

Monitoring activity
The project's immediate outcomes will be monitored by progress
reports, a final report, and an open literature publication. Ultimate
outcome of the project will be measured by the usefulness of the results
for managing the hydrosystem for multiple purposes, including salmonid
populations, as reflected in hydrosystem management plans of Bonneville,
the Corps, agencies and tribes.

Section 3. Budget

* 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   Mainstem

Recommendation    Tier 3 - do not fund