Ouachita River Floodplain Restoration Upper Ouachita NWR ... · Fish and aquatic invertebrates are...
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Ouachita River Floodplain Restoration Upper Ouachita NWR, Louisiana Steve Haase₁, Dan Weber₁, Joe McGowan₂, Tom Kennedy₁, Ronnie Ulmer₁, and Chris Rice₁ (The Nature Conservancy, Louisiana Chapter₁, USFWS₂) Partners and Sponsors USFWS, USGS Wetlands Research Center, Louisiana State University, The University of Louisiana at Monroe, U.S. Army Corps of Engineers, EPA, LDEQ, Caterpillar, Shapiro Family, Lowes, Coypu Foundation, McKnight Foundation, Mott Foundation, and YSI Inc. Water Quality Monitoring Anticipated outcomes include: 1) greater flood retention, 2) reduction in nutrients and sediments exported to the Ouachita River, and 3) reestablishment of floodplain functions and processes. The scale of restoration (90,000 acres total - 20,000 acres floodplain bottomland plus 70,000 acres upland watershed) can serve as a demonstration site for future floodplain reconnection and restoration throughout the lower Mississippi River Valley. Flood pulse was monitored with paired ISCO carrousel samplers and YSI sondes (real-time water quality data) along restored streams. ISCO units (on 10 ft platforms) and floating YSI units (mounted on telephone poles) were positioned to accommodate extreme water fluctuations (up to 30 ft) across floodplain. First year (2009-2010) results indicate increasing trends for sediment, oxidized nitrogen and soluble phosphorous increase as water reenters the Ouachita River from Mollicy Farms suggesting that flood recession (April-May) is a time of significant release of these potential contaminants. Fish and aquatic invertebrates are sampled biannually. First year (2009-2010) results indicate that the adjacent forested floodplain (control) is more productive than degraded Mollicy Farms (aquatic insects 1.6X and fish 3X more productive). Forested Control Interior Mollicy Total suspended solids values (Nitrate values and ortho-P exhibit similar trends) Biological Monitoring Hydrologic Restoration 1969 2009 Construction of the main levee surrounding Mollicy Farms, decades of drainage and modifications to natural bayous, and construction of interior levees and ditches have significantly altered hydrology and functionally disconnected the floodplain from the Ouachita River. Creating a new functional stream (Benson Slash AR 2006) A rebuilt functional channel (Benson Slash AR 2007) Mollicy Bayou Levee breach and channel creation Mollicy Bayou Reconnection to Ouachita River Shiloh Creek Levee breach and channel creation Shiloh Creek Reconnection to Ouachita River 1.25 million cubic yards of levee were removed during the creation of 6 breaches reestablishing the connection of former floodplain streams to the Ouachita River. Mollicy Farms boundary levee (30 ft tall/150 ft wide) NW corner of Mollicy Farms and the Ouachita River In an effort to reestablish a functioning floodplain, degraded stream courses will be improved or recreated as needed. Ditches will be filled and interior levees and berms taken down. ISCO sampling YSI ISCO The Nature Conservancy, the U.S. Fish and Wildlife Service, and partners have joined to selectively breach 17 miles of 30 ft high levee surrounding the 20,000 acre Mollicy Farms Unit of Upper Ouachita NWR to reestablish flood pulses from the adjacent Ouachita River with the historic floodplain. A multi-year monitoring program will document long-term trends in water quality, ecosystem services, and biological community condition.
Transcript of Ouachita River Floodplain Restoration Upper Ouachita NWR ... · Fish and aquatic invertebrates are...
Ouachita River Floodplain Restoration
Upper Ouachita NWR, Louisiana
Steve Haase₁, Dan Weber₁, Joe McGowan₂, Tom Kennedy₁, Ronnie Ulmer₁, and Chris Rice₁
(The Nature Conservancy, Louisiana Chapter₁, USFWS₂)
Partners and Sponsors
USFWS, USGS Wetlands Research Center, Louisiana State University, The University of Louisiana at Monroe, U.S. Army Corps of Engineers, EPA, LDEQ, Caterpillar, Shapiro Family, Lowes, Coypu Foundation, McKnight Foundation, Mott
Foundation, and YSI Inc.
Water Quality Monitoring
Anticipated outcomes include: 1) greater flood retention, 2) reduction in nutrients and sediments exported to the Ouachita River, and 3) reestablishment of floodplain functions and processes. The scale of restoration (90,000 acres total - 20,000 acres floodplain bottomland plus 70,000 acres upland watershed) can serve as a demonstration site for future floodplain reconnection and restoration throughout the lower Mississippi River Valley.
Flood pulse was monitored with paired ISCO carrousel samplers and YSI sondes (real-time water quality data) along restored streams. ISCO units (on 10 ft platforms) and floating YSI units (mounted on telephone poles) were positioned to accommodate extreme water fluctuations (up to 30 ft) across floodplain.
First year (2009-2010) results indicate increasing trends for sediment, oxidized nitrogen and soluble phosphorous increase as water reenters the Ouachita River from Mollicy Farms suggesting that flood recession (April-May) is a time of significant release of these potential contaminants.
Fish and aquatic invertebrates are sampled biannually. First year (2009-2010) results indicate that the adjacent forested floodplain (control) is more productive than degraded Mollicy Farms (aquatic insects 1.6X and fish 3X more productive).
Forested Control Interior Mollicy
Total suspended solids values (Nitrate values and ortho-P exhibit similar trends)
Biological Monitoring
Hydrologic Restoration
1969 2009Construction of the main levee surrounding Mollicy Farms, decades of drainage and modifications to natural bayous, and construction of interior levees and ditches have significantly altered hydrology and functionally disconnected the floodplain from the Ouachita River.
Creating a new functional stream(Benson Slash AR 2006)
A rebuilt functional channel(Benson Slash AR 2007)
Mollicy BayouLevee breach and channel creation
Mollicy BayouReconnection to Ouachita River
Shiloh CreekLevee breach and channel creation
Shiloh CreekReconnection to Ouachita River
1.25 million cubic yards of levee were removed during the creation of 6 breaches reestablishing the connection of former floodplain streams to the Ouachita River.
Mollicy Farms boundary levee(30 ft tall/150 ft wide)
NW corner of Mollicy Farmsand the Ouachita River
In an effort to reestablish a functioning floodplain, degraded stream courses will be improved or recreated as needed. Ditches will be filled and interior levees and berms taken down.
ISCO sampling
YSI
ISCO
The Nature Conservancy, the U.S. Fish and Wildlife Service, and partners have joined to selectively breach 17 miles of 30 ft high levee surrounding the 20,000 acre Mollicy Farms Unit of Upper Ouachita NWR to reestablish flood pulses from the adjacent Ouachita River with the historic floodplain. A multi-year monitoring program will document long-term trends in water quality, ecosystem services, and biological community condition.
