Introduction
The Albert Powell Fish Hatchery in Washington County, Maryland is the site of the Beaver Creek restoration project - a cooperative effort by the Maryland Department of the Environment, Department of Natural Resources, U.S. Fish & Wildlife, Natural Resources Conservation Service and the Washington County Soil Conservation District. Construction was completed on approximately 1,000 linear feet of Beaver Creek in the Fall of 1999. Severe erosion at Beaver Creek was caused by many years of cattle use that had eliminated all of the vegetation that would normally protect the waterway and floodplain.
Restoration Plan
Initial survey and stream data were collected in the Summer of 1996. To address the severely degraded condition of the site, a variety of restoration and stabilization and enhancement methods were developed. The restoration plan included re-alignment of Beaver Creek, decreased slope of the stream banks, re-establishment of stream bank and floodplain vegetation, and placement of numerous rock structures along and within the channel.
A Tour of Stream Restoration Methods
The photographs below illustrate some of the techniques and methods commonly applied by natural resource managers to repair and stabilize degraded streams. Degraded streams are characterized by widened and/or deepened channels, steep channel banks, channel banks that are (or have) collapsed, and loss of stream bank and floodplain vegetation. It is important to recognize that stream morphology - or the physical characteristics of the stream and its floodplain - play an important role in the overall function of an ecosystem. Stable streams are "healthy" streams, and that means clean water and a productive, diverse environment occupied by fish, wildlife and birds.
To learn more about Beaver Creek (part of the Antietam Creek Watershed Project) and other restoration projects in Washington County, contact the Washington County Soil Conservation District at: 1260 Maryland Avenue, Site 101, Hagerstown, MD 21740 (301) 797-6820 or refer to their website at http://www.mda.state.md.us
Stream Morphology and Ecology
A stone cross-vein structure built in the channel directs the flow of water at the confluence of two small streams. The cross-vein arms protect the banks from erosion by directing the flows toward the center of the channel. A plunge pool forms downstream of the cross-vein providing habitat for fish and other aquatic organisms. Wetland vegetation provides food and shelter for wildlife and habitat for a variety of insects, amphibians and birds. The herbaceous vegetation in the foreground (center) is commonly known as watercress. In the floodplain (top, left), saplings have been planted to help stabilize sediments during periods of high flow when the stream overtops its banks.
Stream Bank Stabilization
Large stones, placed along the stream bank, help protect a mature maple tree from the erosive forces of flood flows. The structure deflects water away from the stream bank which had been eroding previously. The tree's root system will help stabilize floodplain sediments during flood flows and prevent further stream bank erosion. Also, trees in the floodplain or bordering streams provide shade which reduces the in-stream water temperature during warm weather months. Trees provide habitat for a variety wildlife, birds and insects throughout the year.
Stream-side Buffers
A heron seeks shelter under a foot bridge spanning the stream channel. Notice the lush streamside
buffer which includes an abundance of herbaceous vegetation and mature trees. Streamside vegetation forms a buffer that reduces storm flows and traps sediment and nutrients before they reach the stream.
In-Stream Habitat
Looking upstream, a small pool has formed beneath a cross vein which provides habitat for fish and a variety of macroinvertebrates that live on the channel bed. Note the bright orange flowers of Jewelweed (foreground, left), a wild species of the hydrid flower Impatiens.
Stabilization Structures
Looking downstream, the cross-vein helps to stabilize the stream bank and directs flow toward the center of the channel. Cross-veins function as local grade control structures which help reduce the velocity of flow in the channel, protecting the channel bed from erosion.
