What is Stormwater Runoff, and Why is it Important?
Stormwater runoff is rain or snowmelt that flows over the ground and into the City's stormwater system or directly into creeks and streams.
As this runoff flows, it can pick up and transport harmful pollutants such as oils and greases, heavy metals, pesticides, fertilizers, trash and debris, sediment, and animal wastes.
Our storm drains do not connect to water treatment facilities, but rather drain untreated into local waterways. Pollutants are carried along with stormwater runoff into our creeks, streams, and the Rivanna River.
As a result, contaminated stormwater runoff is a major source of pollution to our local waterways. Excessive contamination of runoff causes sedimentation of our streams, water quality degradation, and unhealthy water conditions for humans and wildlife.
Impervious Cover, Stormwater Runoff, and Stream Health
The biggest influencing factor on stormwater runoff is the presence of impervious surfaces, which are any surface coverings that do not absorb water, including roads, roofs, and parking lots. In urban environments such as Charlottesville, large areas are covered with impervious surfaces.
There are almost 99 million square feet
of impervious surface in the City.
That is enough to cover over 1,700 football fields!
As a result, water cannot soak into the ground, and instead drains into the stormwater system, and then our creeks and rivers, much faster then it naturally would. This rapid drainage, along with the increased quantity of runoff results in high peak flows in waterways during storms, causing severe erosion of stream banks, scouring of stream beds, excessive sedimentation, and flooding.
Sediment loading is recognized as one of the greatest threats to the Rivanna River and the Chesapeake Bay; sediment carries pollutants that have bonded to it into waterways, suspends in the water column and blocks sunlight from aiding in the growth of aquatic vegetation, clogs the gills of fish (sometimes suffocating them) and eventually destroys aquatic habitat in streambeds when it settles. Impervious cover also prevents stormwater from infiltrating into the ground and recharging the groundwater supply. This leads to small creeks and streams drying up during prolonged periods of dry weather, contributing to drought conditions.
What is a Watershed?
A watershed is an area of land where all water drains into a common waterway, be it a stream, river, lake, wetland, estuary, or even the ocean.
Since all water runs downhill due to the force of gravity, watershed boundaries are typically comprised of ridgetops or high elevation areas. A watershed can be very large and can cover several states. For example, the Chesapeake Bay watershed encompasses over 64,000 square miles, and consists of parts of New York, Pennsylvania, Maryland, West Virginia, Delaware and Virginia.
Watersheds can also be very small, encompassing a few small streams or wetland areas. Charlottesville lies in the Rivanna River watershed, which is a medium sized watershed, encompassing 766 square miles. The Rivanna River watershed is nested within the James River watershed, which lies within the even larger Chesapeake Bay watershed (pictured at left).
For more information on your local watershed, the Rivanna River watershed, visit the StreamWatch website.
Where does our Stormwater Drain?
Stormwater in Charlottesville flows from smaller creeks such as Rock Creek, Schenks Branch, Lodge Creek, and Pollocks Branch, into larger creeks like Moores Creek and Meadow Creek, and eventually into the Rivanna River. Click here to view a map of the City's local waterways, of which there are over 45 miles.
From the Rivanna River, water flows into the Middle James, or Piedmont Region, of the James River. The James River then takes our water to the Chesapeake Bay. Finally, the water from the Bay ends up in the Atlantic Ocean.
There are over 50 miles of underground stormwater pipes and over 4,000 stormwater structures in the City's system.
Sanitary sewage flows to the wastewater treatment plant, while stormwater drains untreated, directly into local surface waters.
Charlottesville’s Stormwater System and Stormwater Management Program
Charlottesville has a Municipal Separate Storm Sewer System (MS4). This means that stormwater and sanitary sewage are completely separated.
The City's stormwater conveyance system is made up of storm drains, curbs, gutters, ditches, man-made channels, and streams that are connected by a network of underground pipes.
Since our stormwater system drains to surface waters, Charlottesville is required to develop a stormwater management program under the Environmental Protection Agency’s Stormwater Phase II regulations. Since March 2003, the City is covered by the Virginia General Permit for Discharges of Stormwater from Small Municipal Storm Sewer Systems (MS4 Permit). There are six key elements of the stormwater management program; the key elements are addressed through the development and implementation of best management practices (BMPs) and will lead to water quality improvements through the reduction of pollutants to the maximum extent practicable.
Avoiding Stormwater Pollution - Garden Activities
- Landscape design – Use native plants, which are already adjusted to regional climactic conditions, require less irrigation and fertilizer, and are more disease resistant. Consider ground cover in place of some lawn or turf areas, as they require less maintenance and water than lawns. CLICK HERE for advice on native gardening specific to Charlottesville.
Fertilizer Use - The reduction or elimination of fertilizer use is encouraged; if you must use fertilizers apply them sparingly and consider non-toxic options such as composted organic material. Also, only apply fertilizer in the fall, when it will promote root growth and a healthier lawn and garden. Remember that fertilizer can get washed away when it rains and enter the stormwater system, adding excessive and harmful nutrients into local creeks and streams. CLICK HERE for City of Charlottesville advice on organic and natural fertilizers.
Use Mulch – Using mulches in your landscaping and gardening helps to retain water, reduce weed growth, prevent erosion and runoff, and improve the soil for plant growth.
Irrigate Efficiently - Much of the water that is applied to lawns and gardens is not absorbed by the vegetation. When water is applied too quickly, it is lost as runoff along with the top layers of soil. To prevent this, it is important to use low-volume watering approaches such as drip-type systems. In addition, watering should only occur in the early morning or evening, when temperatures are lower and less water evaporates. CLICK HERE for information and advice on water conservation.
Pesticide Use - Like fertilizers, pesticides should be used on lawns and gardens only when absolutely necessary. Pesticide use can be avoided entirely by selecting hearty plants that are native to the area and by keeping them healthy. It is also important to identify any potential pests to determine if they are truly harmful to the plant. If it is necessary to use chemical pesticides, the least toxic pesticide that targets the specific pest in question should be chosen and instructions should be followed carefully. CLICK HERE for advice and tips on the use of natural pesticides.
Pet Waste Management - When walking your pet, please remember to pick up their waste and dispose of it properly. Bagging the waste and throwing it away is the best disposal method. Leaving pet waste on the ground increases public health risks by allowing harmful bacteria and excess nutrients to wash into the storm drain and eventually into local water bodies. Meadow Creek, Moores Creek, and the Rivanna River in Charlottesville are all considered “impaired waterways” for their high bacteria levels, a prime example of why we all need to pick up after our pets.
Trash Management - When trash is not properly disposed of litter enters the stormwater system and eventually our waterways, increasing the risk of flooding by clogging up storm drains and pipes and posing a threat to wildlife and human health. Practice waste reduction to limit the amount of trash you generate by reusing materials, buying products with less packaging, and throwing less away. Participate in recycling programs to reduce the quantity of waste being disposed of in landfills and substitute used materials for virgin materials, thereby reducing the demand for natural resources.
Household Hazardous Waste - That cabinet of cleaners and chemicals under the sink may contain hazardous substances. Learn about how to properly handle and dispose of them.
Rivanna Regional Stormwater Education Partnership
The City is a member of the Rivanna Regional Stormwater Education Partnership (RRSEP). The purpose of this partnership is to coordinate a regional effort to address common stormwater program elements of public education, outreach, involvement, and participation.
To view Public Service Announcements addressing stormwater pollution that the Partnership has produced please click on the links below:
A series of advertisements developed by the RRSEP promoting stormwater pollution prevention have recently run in local newspapers and in local movie theaters. The ads encourage citizens to be mindful of the harmful effects that everyday activities can have on local waterways:
Pollution Prevention Hotline: To report an environmental incident or concern, illegal dumping, or an illicit discharge to the stormwater system or a stream, please E-mail the City of Charlottesville Environmental Sustainability Division.