Streambanks form the interface between land and water and are essential, though frequently overlooked. Streambanks are rarely good for building on or as cropland, but have many necessary uses. Healthy streambanks protect land from erosion, soil loss and reduce flooding. A healthy streambank also helps maintain clean and cool water, something that is very important to wildlife in cold mountain streams, and for drinking water supplies. Many species of birds, insects, and mammals depend on forested habitat along streams. Because of all the uses streambanks have, it is important to take care of them.
Plants with strong root systems are important for streambanks. Strong roots hold the sediment/soil in the streambank in place during time and during floods, meaning there is little to no erosion and no loss of land. It also means little sediment will enter the water. Sediment is the most damaging pollutant in western NC to aquatic wildlife. We have several aquatic mussels and fish species in Western NC that are endangered or threatened due to sediment in water. Vegetation will slow down or prevent stormwater runoff from directly entering a stream. In Western NC, we live in the headwaters of several river systems that provide drinking water to millions of people, including most Western NC towns, so keeping water clean is necessary for ourselves as well.
Mowing streambanks is a common practice that all too often creates problems. The roots from mowed grass are simply not strong enough to hold a streambank in place over time. When streambanks are mowed over the course of time, the banks commonly become highly eroded. This can be hazardous. Once a soil ledge starts to form erosion and loss of land only worsens. This can result in an incised or channelized stream where the stream no longer has access to its floodplain. When a stream can not spread out and access its floodplain, none of the flood water and energy can be dissipated, resulting in much worse flooding.
Land owners have many alternative options to mowing their streambanks that are cheap, simple, look good and still provide easy stream access. Planting native shrubs is a good option. These species can be purchased and planted as live stake cuttings that usually only cost around 50 cents per plant! Land owners can also plant native trees and wildflowers. An even cheaper and labor free option is not mowing or weed-eating along streams at all. This may appear “grown-up,” but it drastically improves wildlife habitat, water quality and benefits the landowner as it reduces erosion, property loss, and flood damage. When streambanks are eroded to the point of having large ledges or are channelized, simply planting the streambanks no longer works to stabilize them. This usually means a costly stream restoration is needed to repair the streambank, or it may continue to erode.
With mowing season in full swing it is important to think about mowing streambanks, and the damage that can occur from doing this. Taking care of streambanks, means taking care of wildlife, whoever is drinking water downstream, your property and saving money long term.
Water Resources is an article series supported by local watershed partners highlighting watershed and community news. The High Country and Toe-Cane Watershed Coordinator positions work to improve water quality and gain associated economic benefits in the watershed by providing education and technical resources and implementing on-the-ground projects. Please see our website for updates on projects, and helpful documents for addressing water related issues: http://www.blueridgercd.com/ or contact: Blue Ridge Resource Conservation & Development, Jessica Janc, High Country Watershed Coordinator in Watauga, Ashe, Alleghany and Wilkes counties firstname.lastname@example.org, (828) 406-6690; Felix Stith, Toe-Cane Watershed Coordinator in Yancey, Mitchell and Avery counties, email@example.com, (828) 279-2453.