Eureka, Missouri
Client:
The Realty Office, Inc.
A hillside above Fox Creek in Eureka, Missouri had been severely damaged from development activities. Fox Creek is considered to be one of the last pristine creeks in the area and downstream of the site is an area being enhanced as part of the Streambank Mitigation Program. The U.S. Army Corps of Engineers, the Missouri Department of Natural Resources, the Missouri Department of Conservation, the U.S. Environmental Protection Agency, and the City of Eureka all were involved in trying to stabilize the slope to protect the creek
Terra Technologies was retained to provide biostabilization recommendations to stabilize the hillside in the form of a Restoration Plan. An agronomic analysis was performed to determine the microbiological and nutrient fertility of the soil system. Chemical analysis of each soil sample indicated the presence of a calcareous soil with a basic pH. High organic matter values suggested that the soil is comprised of plant forms of humus. Sufficient quantities of nitrogen and phosphorus were absent and the existence of a shallow soil system identified the requirement of organic soil remediation for successful completion of restoration efforts. Organic soil conditioning and microbiological inoculation were specified prior to plant material installation.
A bonded fiber matrix (BFM) was specified to stabilize the hillside. A BFM is a special, hydraulically applied mulch, in which fertilizer, seed, inoculants, and other organic materials can be suspended. The BFM differs from traditional hydraulic mulches in that it is resistant to breakdown from the wetting and drying cycle that occurs during periods of rain. A paragerminating seed blend was specified containing a mixture of native riparian and woodland species.
The hillside biostabilization was performed in early April 2002. The two different BFM products were applied Conwed 3000 and Soil Guard to test the effectiveness of the two products. Planting of trees was recommended along the toe of the slope and throughout the hillside for shading of the stream channel. The reforestation was performed in mid-April 2002 and involved the planting of over 250 trees including river birch, green ash, persimmon, sycamore and gray dogwood. Humus and mycorrhizae were placed in the holes created for the seedlings.
While the spring of 2002 was extremely wet with considerable periods of heavy rains, the BFM was successful in protecting the developing vegetation and provided a measure of rill erosion protection. The cover crop of sterile wheat providing short-term erosion protection and the native and woodland species and wildflowers have become dominant to create a very stabile slope that will restore it to pre-construction conditions. The project has been nominated by the U.S. Army Corps of Engineers for a National Restoration Award by the Chief of the Regulatory Branch, St. Louis District. |
