Dutch Hollow Brook Streambank Stabilization Project
Cayuga County Soil and Water Conservation District
Basin Program Funds:
The New York States "1996 Priority Water bodies List for the Oswego-Seneca-Onieda River Basin" states Dutch Hollow Brook is a "significant contributor of sediment to Owasco Lake." The hydro modification and stream bank erosion upstream are both impairing fish habitat and degrading the water quality of Owasco Lake.
Owasco Lake is the primary drinking water source for Cayuga County, serving over 70% of its residents (58,000 people). Dutch Hollow Brook enters Owasco Lake within two miles of municipal water intakes. The "Priority Water bodies List" also states that a "significant bed load deposited in the lower end of the brook is causing people to go in with bulldozers and clean out the area for flood control," thus wiping "out a warm water fish spawning area and is impairing propagation."
The purpose of this project will be to demonstrate various BMP’s for streambank stabilization through the use of fluvial geomorphology. The effectiveness of these BMP’s will be evaluated for many years to come and will allow not only the district, but also other environmental organizations and landowners in the region, to determine which BMP is most effective for any particular erosion problem. The following BMP’s will be implemented (but will not be limited to) during the course of this project:
- Installation of 8 in-stream rock devices (cross vanes and J-hooks), approximately 105 tons per device.
- Installation of 880 linear feet of 12" diameter Filtrexx EdgeSaver streambank stabilization filters socks.
- Installation of 300 yd2 of erosion control blankets
- Implement streambank stabilization BMP’s for at least 1000 linear feet (non-contiguous) on Dutch Hollow Brook, at pre-determined "critical areas".
A total of 460 linear feet of filter sock and 1,000 sq. feet of Eco-Blanket were installed. The filter sock, a synthetic perforated shell, was injected with a blend of compost, mulch, pea gravel and a seed mixture of tall fescue, perennial rye, annual ryegrass, white clover, timothy, Kentucky bluegrass, birds-foot trefoil and wildflower mix. The area for the Filter Sock installation was a priority due to severe erosion directly upstream from a town bridge. The Filtrexx Filtersoxx was developed by Filtrexx International, LLC. The district hired a certified installer for the installation and district staff assisted. This BMP is easily installed in tight, hard to maneuver areas, no large tracked equipment needed for installation, and it is aesthetically pleasing compared to large rock rip rap. When the vegetation is fully grown the filter sock is almost unnoticeable. A triple 19 fertilizer was applied at 300 lbs. per acre. In addition (not funded by this grant) 109' of rock rip rap was installed and an existing land crossing was enhanced with geotextile fabric and stone.
The filter sock was not install on Dutch Hollow Brook. The district has found that the filter sock is a very site specific BMP, in that it requires an open forest canopy to let sunlight in for the plant material to grow, and is most suitable for smaller, low flow streams on streambanks with very little steepness and/or height.
A stream assessment was conducted by Schumacher Consulting Engineers (SCE) for the fluvial geomorphology (FGM) portion of the grant. SCE compiled a plan for the Cayuga County Soil and Water Conservation District (CCSWCD) to implement the FGM structures on Dutch Hollow Brook. Permits were required by NYS DEC and US ACOE in order to complete work. Due to unforeseen circumstances, the CCSWCD had to switch consultants midway through the planning of the FGM project. As of the spring of 2005, a final plan was submitted to the regulatory agencies for review. In September of 2005, both NYS DEC and US ACOE issued permits for the project to be implemented. CCSWCD intends to implement the FGM Rock structures in 2006.
Contact: Mr. Jim Hotaling, (315) 252-4171