Constructing a Wetland on Coal Silt

A former desilting basin that was the disposal site for thousands of tons of sediment dredged from the Schuylkill River for decades is being converted into a wildlife sanctuary and environmental education area.

Renamed Black Rock Sanctuary, the 120 acre site on the Schuylkill River near Phoenixville in Chester County, is in the process of being restored to include a network of high quality wetlands, which will provide breeding and nesting habitat for migratory waterfowl and amphibians.

See the special Black Rock Photo Feature.

The Sanctuary is host to an interactive nature trail designed to explain the complex interconnections and interactions of the man-nature interface.

A major element in the restoration work is the use/reuse of coal fines and other coal waste dredge from the river to create the trail and many of the interactive exhibits/activities.

When finished, the site will host deep water, emergent, palustrine scrub shrub and forested wetland ecotones along with upland forest, old field and meadow ecotones.

Among the specialized displays are a biofilter to demonstrate the difficulties of dealing with surface water runoff and chemical pollution; a series of vernal pools to demonstrate the delicate balance in maintaining a healthy amphibian population; a model of the Schuylkill River and Black Rock Dam to demonstrate the impact of the industrial revolution on the ecosystem of the river; and an interactive display to demonstrate watersheds.

The interpretive stations will be strategically placed to reinforce the multiplicity of ecosystem interactions and demonstrate their dependence on man’s stewardship to keep them healthy.

The history of the Black Rock Basin mirrors the history of many streams and rivers in Pennsylvania affected by uncontrolled coal mining in the late 1800’s and early 1900’s.

By the early 1900’s, waste from upstream coal operations was contributing over 3,000,000 tons of silt annually to the Schuylkill River.

By the early 1930’s so much silt had built up behind the dams of the slack-water navigation system used to carry barges of coal on the Schuylkill and other rivers that navigation ceased, flooding increased, recreation use came to an end, and the river’s value as a water supply was being threatened.

After passing a series of laws to mitigate siltation of the state’s waterways, state government undertook the Schuylkill River Project in 1945 to dredge the river by removing silts to strategically located desilting basins.

In all, some 21 desilting basins were constructed in a public works project valued at over $31.75 million along with the removal of some of the Schuylkill Navigation Company’s canal dams. In the case of the Black Rock basin, an 8,000 foot long berm created an 80-acre basin.

Active dredging use of the Black Rock Basin ended in the late 1950’s. Later, sand, gravel and coal were removed for mineral recycling, leaving the site desolate and pockmarked.

To learn about the rest of the history of Black Rock Basin, go to the Black Rock Basin webpage and read the article by Carl Kelemen of Evergreen Landscape Associates and Robert Folwell, Chester County Department of Parks and Recreation.

The Black Rock Sanctuary restoration project is funded by Chester County, the U.S. Fish & Wildlife Service, the departments of Environmental Protection and Conservation and Natural Resources and the William Penn Foundation for a total investment of over $1.1 million.

For more information, visit the Black Rock Basin webpage .

(Contributed by Carl Kelemen, Evergreen Landscape Associates, 215-887-6607, Roslyn, PA)

2/17/2006