The Marsh Creek Headwaters Best Management Practice (BMP), located downstream from the City Center development on Johnson Ferry Road, will help reduce flooding in the surrounding neighborhoods and improve water quality by treating storm water runoff before it flows into Marsh Creek, the tributary leading into the Chattahoochee River.
Marsh Creek is listed by the Environmental Protection Department as an impaired water body for not meeting the state’s water quality standards primarily due to urban storm water runoff. Working with the Georgia Environmental Protection Department (EPD), this City project should not only improve water quality for Marsh Creek, but could also become a model for regional detention facilities.
Through this regional detention preserve, storm water, dirt, grease, debris and pollutants that wash away during rainstorms, are filtered through a natural water treatment process. Storm water runoff will flow through a bio-retention area that cleans and treats the water with aquatic native vegetation and specially designed soils. The water is then channeled into a wet pond that removes pollutants and sedimentation. A fountain in the wet pond will circulate and oxygenate the water, increasing the number of organisms that consume and break down contaminants. In addition to the cleaning process, the project will also reduce flooding and stream bank erosion.
An added feature is esthetics. Project amenities will include green space, walking trails, and extensive landscaping, as well as educational signage to explain the storm water treatment process.
The City and the EPD, through the Nonpoint Source 319h Grant program, fund this project jointly. Water quality monitoring for this project pre- and post- construction will allow EPD to measure its effectiveness with hopes of replicating the successes in future detention programs.
From Press Release:
Construction has begun to create a regional, multi-use stormwater management facility in Sandy Springs. The Marsh Creek Headwaters Bio-retention facility is designed to improve downstream conditions of the watershed, the area of land where water that is under it or drains off, flows into a common area. The Marsh Creek Headwaters project is part of a larger effort to improve the overall watershed of the Marsh Creek Basin beginning with its headwaters.
The project is anticipated to reduce flooding in the neighborhoods surrounding the immediate headwater area by reducing storm flow between 50 and 90 percent, depending on the severity of the storm event. It is also expected to improve water quality by treating stormwater runoff, reducing pollutants by 20 percent, before it flows into Marsh Creek, the tributary leading into the Chattahoochee River.
Design of the facility incorporates hardscape and softscape features, creating an area that will be an attractive greenspace. Project amenities include a permanent wet pond with a fountain, walking trails, extensive landscaping, benches, educational signage to explain the stormwater treatment process, as well as a bio-retention area with specially selected plant species to remove pollutants from stormwater runoff.
This project is partially funded by a Nonpoint Source 319(h) Grant from the Georgia Environmental Protection Division (EPD). Water quality monitoring during pre- and post- construction will allow the EPD to measure the project’s effectiveness with hopes of replicating the successes in future stormwater treatment programs. The total project cost is estimated at $4.6M. Work is expected to be completed in Spring 2016, weather permitting.
- 4/30/2015: Project Update
- Final Design Completed January 31
- Permitting completed April 1
- Bids Due May 7
- Contract Finalized May 20
Council approves contract June
- Notice to Proceed August
- 6/25/2014 Open House Material
- Project Fact Sheet