Cross Vane In Action

This video taken on May 18th, 2011 shows how the cross vanes function in the stream during a high flow event. The high velocity flow shows how the cross vanes direct the flow of the water into the center of the channel and keep the pressure off of the banks thus reducing bank erosion.

Project Grading Complete

All major grading work for the Watts Branch Stream Restoration project has been completed. Remaining tasks include some instream work following DCWATER utility work in the stream and then final plantings in the Fall of 2011.

Construction of Cross Vanes

Cross vanes are being constructed in the stream between Hunt Place and Minnesota Ave to help keep the water in the center of the channel preventing high flows from eroding the stream banks. The cross vanes are constructed so that the stones in the banks are at a higher elevation than the stones in the center of the channel. The cross vanes also create areas where water can pool downstream of them which create areas for fish habitat and fish passage. The stones used in construction of the cross vanes are large, heavy, and strategically placed so that they will not be compromised during heavy storm flows.

Watts Is Subject to High and Low Flows

Because Watts Branch is part of a highly urbanized watershed during rain events the volume and velocity of water can change drastically in a matter of moments. During normal non-rain conditions throughout the year the average flow rate of the stream ranges from 2-4 cubic feet per second. However, when heavy storm hit the watershed at times the flow rate of the stream has increased from 2 cubic feet per second to 900 cubic feet per second. This is because there is so much impervious space in the watershed that directs the water into storm drains and does not allow the rain water to naturally seep into the earth to recharge the water table.

The stream restoration project will not reduce the volume and velocity of stormwater entering the stream, however, it will help to manage how the water flows and it will help reduce the rate of erosion along the stream banks.



The photo at the top of the post show Watts Branch during a rainless week in November 2010 while the photo toward the bottom of this post show the same location during a heavy rain storm in August 2010.

Watts Branch Watershed and Storm Sewer Map

Watts Branch Stream Restoration-In Progress!!!

The Watts Branch watershed covers an area that is roughly 2,400 acres with 47% of the watershed with the borders of the District and the remaining 53% of the watershed upstream in Maryland. Years of urbanization and suburbanization has caused the stream to degrade over time. After a thorough assessment, design, and planning process The Watershed Protection Division of the District Department of the Environment will be breaking ground on a 1.75 mile stream restoration project on the Watts Branch tributary of the Anacostia River in December 2010. The first phase of the project began in October 2010 with invasive species control work taking place along the entire stream corridor from Southern Ave. to Minnesota Ave. NE. This project involves a partnership among the District Department of Parks and Recreation, the U.S. Fish and Wildlife Service, and the Natural Resources Conservation Service of USDA. The stream restoration will reshape the channel using natural channel stream design techniques to reduce channel erosion, create pools and riffles to support aquatic life, and reestablish streamside vegetation through the plantings of 10,000 trees and shrubs in the riparian corridor.

In addition to stabilizing the stream banks through re-grading and the planting of an extensive riparian corridor the stream banks will be further stabilized by the installation of rock structures such as cross vanes, j-hooks, and double winged deflectors to help keep the high velocity flows in the center of the channel and off the banks in both straight and curved stretches of the stream. These structures will help improve both habitat conditions associated with the streams while also protecting infrastructure in and near the stream.

Upon completion of the project and over the ensuing years after completion there will be an aesthetically pleasing stream corridor filled with native riparian plant species that will both help reduce erosion and provide habitat for wildlife. This project will not only improve the environmental health of the stream but will also complement an array of District Government and local non-profit work in Marvin Gaye Park which includes but is not limited the construction of a bike trail that parallels the stream, sewer line replacement work along the stream valley, native tree plantings and low impact development projects throughout the watershed, and a local green jobs training program along the stream corridor.