Initial Fish Response to 0706 Lewiston Dam Reach Gravel Augmentation Project

1
Initial Fish Response to 07/06 Lewiston Dam Reach
Gravel Augmentation Project
Prof. Greg Pasternack
2
Trinity SHIRA Preliminary PlanningProblem
Identification
UCD and TRRP meeting and field trip
(2/6/03) --gtThe reach immediately below
Lewiston Dam is a heavily used chinook and
steelhead spawning area, but the habitat quantity
and quality is too low for the population of
adult spawners. Can it be increased? -gtGravel
augmentation to re-establish the coarse sediment
regime is planned below Lewiston Dam, but the
locations and methods of gravel placement need
further study. How should gravel be placed?
3
SHIRA PPC Modeling450cfs Habitat Availability
Steelhead spawning and all species fry habitat
lacking
4
Indicator Species Ecological Restoration Concept
SHIRA is based on the ecological concept of
indicator species that suggests that a there
exist species whose needs are similar to and
reflect the needs of a broader group of species,
and whose abundance is an indicator of ecosystem
health. SHR focuses on improving spawning
habitat, because such improvements not only
improve spawning success (Elkins et al., in
press), but can also yield benefits to aquatic
invertebrate habitat and productivity (Merz and
Setka, 2004 Merz and Ochikuba Chan, 2005), egg
incubation success (Merz et al, 2004), fry
habitat and productivity (Merz et al, 2004), and
the entire food web.
5
Trinity SHIRA Experiment
Project Modes Used
Project Phase
Phase 1 Preliminary Planning
Phase 2 Pre Project Characterization
Phase 3 Design Development
Phase 4 Final Design Selection
Phase 5 Construction
Phase 6 Post Project Assessment
Phase 7 Long-term Monitoring
Adaptive Management
MODE KEY
Conceptualization Mode
Data Collection Mode
DCM
CM
Modeling Mode
Scientific Exploration Mode
MM
SEM
6
Trinity SHIRA Preliminary PlanningSite Selection
for Trinity SHIRA

• Is this a location that ought to have spawning
  habitat? YES
• Is hydraulic head available to provide desired
  velocities at spawning flow releases? YES
• Can natural processes be restored to this reach?
  MAYBE

7
Lewiston Dam Reach Pre-Project Long Profile
8
Lewiston Dam ReachRiffle-Pool Self-Maintenance?
Pools and riffles behave the same
AT A STATION RELATIONS
Pools will never scour more than riffles in
current regime
9
Design 6 Blanket Fill with 2 Asymmetrical
Longitudinal Bars
Note channel widening
NET
10
Project Implementation

• Led by Joe Reiss, TRRP
• TRRP and UCD worked together to adjust design 6
  as needed to match on-the-ground realities.
• adjusted road side-slope and channel width, for
  example.
• Planned for 9000 tons of gravel addition, but
  change in costs 2003-2006 resulted in having to
  break the project into two parts.
• Part 1 involved excavation, vegetation and muck
  removal, and placement of 2500 tons of gravel.
• Part 2 will involve placement of remaining 6500
  tons in 2007

11
Construction
12
Blimp Aerial Photography
13
Riffle 2 Entrance Pre versus Mid
14
Central Bar 1 Pre vs Mid
flow
15
Mid-Actual vs Design
16
Fish Response
Waiting for results to be made available Will
go out this afternoon and GPS all redd locations
17
Trinity SHIRAConclusions
Highly detailed pre-project characterization was
conducted for the Lewiston Dam Reach using broad
array of interdisciplinary tools.
The reach is A) highly unnatural, B) deeply
scoured, C) highly armored, D) lacking in fry
habitat, E) lacking in spawning habitat, F)
abundant in juvenile and adult habitat
Gravel placement is underway. Design and
implementation are being adapted to meet issues
as they arise.