Washington Road Stream Restoration
The stream corridor runs along the east side of Washington Road from just south of Jadwin Hall to Faculty Road (see map). The work involved widening the stream and adding a flood plain to decrease the velocity of the stream when flooding occurs, and decreasing the slope of the stream to slow the everyday rate of the water and to stop erosion.
The stream restoration is intended to correct environmental degradation caused by past stormwater runoff (previously corrected by stormwater management implementation).
About 1,400 linear feet of stream channel along lower Washington Road has been graded and re-shaped to form grade control and habitat features. Stacked stones provide stream bank protection. The restored stream slows sediment and reduces sediment runoff and should improve the water quality of Lake Carnegie.
The project was substantially complete in February 2012, with landscaping and tree planting to follow in the spring and fall.
This ecological restoration of the entire Washington Road stream corridor will enable it to sustainably handle stormwater runoff as well as the everyday flow.
To decrease the rate of the stream, several bends have been added so that it meanders from east to west as it flows from north to south. To reduce the natural slope of the stream, a series of step pools have been created so that the water travels as if on a series of stairs. By decreasing the velocity of the stream, planners hope to cut the erosion of Washington Road and the bedrock, eliminating the constant deposits of sediment into Lake Carnegie.
In addition, plantings will be added to stabilize the flood plain and slopes while enhancing the Washington Road woodland valley experience. The plantings also will enhance the nutrient balance in the stream, improving the water quality.
As part of the nearby Frick Chemistry Laboratory project completed in 2010, the riparian buffer area has been improved, enhancing the biohabitat, restoring the woodland and adding a nature path.
Working with the University on the project have been Vanasse Hangen Brustlin of Watertown, Mass., landscape architects, and VanNote-Harvey of Princeton, engineering consultants.