Howard’s Branch stream and wetlands restoration

This wetland and stream enhancement project was designed to support the reintroduction of an Atlantic white cedar, (Chamaecyparis thyoides (L.) B.S.P.) wetland by creating a seepage wetland supporting an Atlantic white cedar community in a degraded stream valley previously impounded for use as a drinking water reservoir.  A series of cobble weirs and a network of sand berms was placed over a dry lakebed to mimic the hydrology found in natural Atlantic white cedar sites. In April 2001 construction of the Howard’s Branch project was completed with the planting of 1,000 Anne Arundel County, Maryland-endemic Atlantic white cedar. Plants were propagated from the 10 remaining stands of the species on the western coastal plain of Maryland.  The modifications necessary to establish the sand seepage hydrology suitable for the establishment of seepage wetlands result in a series of well vegetated pools, sand seepage beds replete with above and below-ground biomass, and flow paths through low areas dominated by native wetland plants.  The physical effect of the pools and their many plant stems is to reduce water velocity and facilitate removal of suspended particles and their associated nutrients and/or contaminants.  Uptake and adsorption of nutrients and contaminants by the plant stems in the pools yields additional benefits.  The sand seepage bed supports organisms and processes which remove nutrients and contaminants as they pass through the sand bed.  The six (6) year old project has been successful and serves as inspiration for similar projects and related applications.