In 2008, with funding from the Clean Water Management Trust Fund, RiverLink implemented two stream restorations and a variety of stormwater BMPs in the Hominy Creek Watershed. These projects along Rhododendron Creek in West Asheville Park and Buttermilk Creek in Malvern Hills Park were developed to prevent future stream bank erosion and catch and treat polluted stormwater before it enters the creeks. Both of these creeks drain to Hominy Creek a major tributary of French Broad River.
Restoring a stream brings it back to what Mother Nature intended and re-establishing the natural structure, function and stability of the stream. RiverLink accomplished this through recreating the curves and meanders back into the creek and installing rocks or logs in a series of V formations. These in-stream structures help control the speed of the water and direct the main flow into the center of the stream and away from the sides this preventing further erosion. These measure help reduce erosion of the streambank, improving native plant habitat. The riffles and polls created by these structures also add oxygen to the water and improve habitat.
Parking lots and roofs are impervious surfaces that cause water to flow so fast it doesn’t soak into the ground and recharge the ground water. As rain drops on roofs, parking lots and roads it picks up soil, pollutants and other debris. RiverLink installs stormwater best management practices (BMPs) such as rain gardens, bioretention areas, and constructed wetlands in areas to capture the water flowing off these surfaces and to reduce its velocity, but primarily to filter and clean the water before it enters the stream.
Plants along the bank of a creek, stream or river are called the riparian buffer. RiverLink planted this riparian buffer with a wide variety of native drought resistant plants. Buffers are critical to a stream’s health; they slow the water and help any dirt coming from upstream roofs and parking lots. We planted these buffers with help from the neighborhood and lots of volunteers with “live stakes” or cut braches that will also grow and help stabilize the bank.
Prior to this project Buttermilk Creek was identified as an un-named tributary of Hominy Creek. As part of the community engagement RiverLink and a group of neighbors led a “name the stream” contest. This contest provided the opportunity for neighbors to learn about the history, natural features, and significance of the creek and its watershed, building a sense of ownership. The winning name, Buttermilk Creek, comes from its past. A few long term neighbors recollected the stream often running white with a mild odor, because of the Milk Co plant. Prior to entering the park, across Patton Ave. the stream passes by the Milk Co plant and for decades prior to the Clean Water Act of 1972, the water used to rinse the milk trucks drained straight to the creek. This was the source of the white color and mild odor, and the inspiration for the name. It works well as buttermilk and hominy make great cornbread, a North Carolina tradition.
Six stormwater BMPs where designed into the project to improve water quality and protect the stream, these include 3 bio-retention areas, an infiltration swale, and rain garden. The rain garden is located adjacent to the Sulphur Springs Rd. entrance, and receives runoff from the sidewalks, pool patio, and overflow from the road. This is a great example of a wet rain garden that provides habitat for frogs and other animals, while improving water quality and reducing stormwater flows. One bio-retention area is just downstream from the rain garden between the walkway and the stream. These features have a couple of white pipes sticking out of the ground, which connect to an underground drainage system and allows for maintenance. The other bio-retention areas are located by the Rumbough Place entrance and parking lot. The upper bio-retention sits between the road and walkway utilizes curb cuts to capture and treat stormwater runoff from the road way. The lower bio-retention area adjacent to the parking lot receives runoff from the parking lot and drive, slowing and treating the water before it enters Buttermilk Creek. An additional infiltration swale was installed by the tennis courts to capture, slow and treat runoff from the walkways, court, and steep slopes of the park.
Adjacent to the small parking area off Morris St. is the smaller of the two bio-retention areas. This project was constructed with assistance from neighborhood volunteers, Francine Delany, and Asheville Green Opportunities. This garden filters water from the road and parking lot, prior to entering the park. Within the basin of the park adjacent to the baseball field is a large bioretention area, which captures and treats rainwater runoff from both Virginia Ave, and Morris St. A vegetated swale directs water from Virginia and around the ball field to the bio-retention area. A constructed wetland installed just south (downstream) from the large bio-retention. A wetland was selected to treat runoff in this location, because a perched water table was identified during the project altering original designs.