DELAWARE RIVER BASIN COMMISSION

Restoration

One nationally-prominent individual engaged in stream restoration is Dave Rosgen of Wildland Hydrology, Inc., Pagosa Springs, Colorado. In his two-week course on this topic (Rosgen 1999), he stresses restoring streams to stable plan, profile, and cross section properties using dimensionless relationships that exist in reference stable streams. A rigorous, forty-step design analysis is required to determine the dimensions for the reconstructed stable stream configuration. Reconstructed streambanks are stabilized by root wads, boulders, and most importantly well-established, appropriate vegetation. Rosgen also stresses using the largest practical earthmoving equipment to complete projects as rapidly as possible.

Many projects in the East are limited to such small parcels of land that stream side revegetation is the primary method of restoration. If a remnant composition of desirable plants exists, natural restoration may be practicable. Most riparian shrubs and trees are capable of resprouting and can recover from extensive abuse (Platts et al, February 1987).

Rosgen project: completing a rock vane on the Blue River, Colorado. The vane is specifically designed to minimize erosive velocities near the streambank, direct flow to the channel center, and to provide habitat for trout.

Typical root wad installation. The trunks of trees are anchored into the stream bank, with the root wads providing resistance to the shear force of high flow velocities. Over time, the root mass of stream bank vegetation replaces the slowly decaying root wad.

Bioengineering and streambank stabilization along the East Branch of the Perkiomen at Groff's Mill Park, Lower Salford Township, Montgomery County, PA. Note wood ice deflector to protect installed vegetation. Also note, at upper right, the remaining eroding stream bank, which will be restored in a next phase of the project. The project has been sponsored by the Perkiomen Watershed Conservancy and others. The design and installation was by Munro Ecological Services, Inc.

Go Example Page

Waterway Corridors Home Page