WSSC Water Resources Engineering Services On-Call
Biohabitats has been working with the Washington Suburban Sanitary Commission (WSSC) and the City of Rockville to protect WSSC assets that have become exposed as a result of stream channel migration, as identified in a Consent Decree with the U.S. Department of Justice. Hydrologic impacts from years of development have led to channel migration and the exposure of several WSSC sanitary sewer lines. The exposed pipes are vulnerable to damage from debris flows in the streams as well as infiltration or exfiltration caused by the differential pressures between the stream and pipes.
To address these concerns, Biohabitats developed robust solutions that minimize disturbance to adjacent natural resources and meet the needs of all stakeholders. Restoration plans included covering and protecting the exposed infrastructure with grade control structures; relocating channels and reintroducing natural stream channel design features; and protecting the existing forest, stream and park experience to the greatest extent possible. Design efforts included geomorphic assessment, natural resource investigation, forest stand delineation, hydrologic and hydraulic modeling, development of specifications, and estimating probable construction costs. We also obtained permits from the Maryland Departments of the Environment and Natural Resources.
Biohabitats has also provided emergency stream restoration services for sites across Montgomery and Prince George’s Counties under this contract. Fulfilling WSSC’s demands for fast turnaround of design documents, local and state permit support, and construction oversight Biohabitats has helped expedite essential repairs for failing infrastructure within streams and other sensitive areas. Even in an emergency repair context, our approach was to protect both the infrastructure and the surrounding natural areas. Since April 2010, Biohabitats has designed and provided as-built drawings for emergency repairs for nine sites. Biohabitats has also fully executed construction oversight for seven sites, including three owned by the Maryland-National Capital Park and Planning Commission (M-NCPPC).