In February 2003, the Baltimore District Army Corps of Engineers awarded to Cottrell Contracting a $1.9 million contract for the dredging of the Anacostia River. 

The Anacostia River project is an excellent example of a successful environmental project.  The Anacostia River is a tributary of the Potomac River that runs through our nation’s capital.  From the river, you can see such sites as the National Arboretum, as well as the old RFK stadium where the Washington Redskins football team played not too long ago.  The Anacostia had not been dredged in over 30 years and was dying due to lack of oxygen from the shoaling that had taken place.  It was obvious that the river needed dredging; however, there was no land available to build a dredge material containment site.  The answer?  Dredge the channel to restore depth and health to the river and use the dredge material beneficially to create inter-tidal wetlands adjacent to the river.   

Due to the fact that the portion of the river to be dredged was only accessible by small dredging equipment, Cottrell Contracting chose to utilize its 12” Dredge Blue Ridge for the project.  Prior to the dredge’s arrival, over 5,000 linear feet of sheet pile was driven to establish two “cells” that would later become wetlands after being filled with dredge material.  The average water depth in the cells before dredging began was approximately –3.5 mean low water (MLW).  The project called for dredge material to be pumped to an elevation of +1 ½ MLW to fill the cells.  The allowable tolerance was plus or minus 6”.  To ensure that the final grade was achieved, Cottrell used an amphibious excavator to grade the pumped material to its final elevation.  Cottrell crew, experienced from many prior environmental projects, pumped over 200,000 cubic yards into the wetland cells.  All material was checked for final grade by the Army Corps of Engineers and found to be within tolerance.  The two cells were given time to consolidate and planted with native plant species.  The result was a tremendous success.

Cell #1 after filling and planting