9389

• UCREFRP Catalog Number: 9389
• Author: Birchell, G. J., K. Chrisopherson, C. Crosby, T. Crowl, J. Gourley, M. Townsend, S. Goeking, T. Modde, M. Fuller and P. Nelson.
• Title: The Levee Removal Project
• USFW Year: 2002.
• USFW - Doc Type: Assessment of Floodplain Habitat Restoration in the Middle Green River.
• Copyright Material: NO

species survivorship.
The enhanced productivity of floodplain wetlands may also be an important
factor in enhancing survivorship of adult native fish. Modde (1996), Tyus and Karp
(1989), and Holden and Crist (1981) have all documented the use of floodplain
wetlands or low velocity areas by adult razorback sucker. Wydoski and Wick (1998}
have speculated that these areas may be important post-spawning feeding and resting
areas. The adult fish may utilize these highly productive areas to replace valuable
energy reserves that were used for spawning.- Feeding and resting habitats, therefore,
may be important to enhance the survivorship of razorback suckers in the Upper
Colorado River Basin (UCRB).
GOALS, OBJECTIVES AND HYPOTHESES
The primary goal of the Levee Removal Program and this study is to restore and
enhance natural floodplain habitats and functions that support recovery of endangered
fishes in the UCRB (especially the razorback sucker) through levee removal (Lentsch et
al. 1996). Natural floodplain functions include: annual flooding, enhanced water
temperatures, increased primary productivity, production of food organisms for fish,
high water quality, shelter from high velocities, vegetative cover for predator avoidance,
and improved fish access for nursery rearing, feeding and spawning. The .specific goal
of this study was to evaluate the system responses to levee removal and make specific
recommendations concerning the value of floodplain reconnection for endangered
species (specifically razorback sucker) recovery.
Objectives and Hypotheses:
1. Reconnect selected floodplains with the river channel.
In the Spring of 1997, levees were breached at three sites: Bonanza Bridge, The
Stirrup, and Old Charley Diked. Levees were breached at Horseshoe Bend,
Baeser Bend, Above Brennan, Johnson/J4 and Leota L7/7a in the spring of
1998.
2 Evaluate the system responses to levee removal.
FY - 1996
Designated year to collect baseline data prior to levee removal.
FY-1997 - 1999
a. Determine if native or nonnative fish utilize inundated floodplain habitats (and
the associated river channel) differentially (proximate response).
b. Determine if native or nonnative fish increase in areas (river reaches) of high
floodplain habitat inundation (ultimate response).
c. Determine if native and nonnative fish responses to floodplain inundation are
different in river reaches that originally had high or low nonnative fish densities
(based on current estimates).
d. Determine if native fish habitat utilization, growth, and survival are negatively
1.5