Stormwater Management
Management by Natural Processes
By using natural processes to manage stormwater quality and quantity, UVa project managers are creating greenspace on Grounds that is beneficial to both the local community and the natural environment. Greenspace is generally defined as an area that incorporates vegetation such as grasses, trees, and shrubs into a natural like setting. Sometimes these areas include streams and other water bodies and their associated riparian buffers. The Lawn is an example of greenspace in the middle of the highly developed area while the Dell is an example of a restored riparian ecosystems completed with its own flowing steam and pond. Greenspace provides places where people can enjoy sunlight, trees, fresh air, and the natural environment they create. These greenspaces also provide a valuable service by improving the quality of stormwater runoff while reducing the quantity through infiltration, retention, and evapotranspiration.
This Stormwater Management Retention Pond collects stormwater runoff from the Health Sciences area of UVa. Here physical and biological processes remove entrained sediments and other contaminants from this water before it is discharged into the tributary of Moores Creek. The pond area also provides a park-like setting for all to enjoy and is an established ecosystem where fish, frogs, and other animals can be observed.
Vegetation growing along the daylighted portion of Meadow Creek.
How Natural Processes work
The natural environment has a multi-phase system for removing pollutants and suspended particles from stormwater. Chemical, physical, and biological process all work to dramatically improve the quality of water flowing through streams, ponds, and estuaries.
Ways the environment removes pollutants from water:
Physical – the physical removal of pollutants usually occurs by filtration and the gravitation settling. Dense plants and their associated soil systems along riparian buffers are efficient at the removal sediments from waters flowing over them. The reduction of water velocity as it enters pond and lake systems causes the gravitational settling of suspended soil and other particles.
Chemical – chemical processes in wetlands are know to remove many contaminants from water including metals, such as copper, lead and iron, and dissolved phosphorus. Dissolved metals can also be adsorbed onto the surface of particles in the water and then settle to the bottom as the particles settle.
Biologic – aquatic plants, algae, and microorganisms uptake many nutrients from the water that are necessary for their growth. These nutrients include nitrogen and phosphorus, which are common forms of pollution. Microbes in the environment can also function to break down toxic organic compounds into less harmful compounds.
Steam rising off of Meadow Creek on a cold morning.
Stormwater Management Practices at UVa
There are many natural ways to improve water quality, decrease stormwater runoff, and create greenspace on Grounds. These include the following:
- Stormwater Phase II MS4 Implementation – UVa has a stormwater discharge permit under the Phase II MS4 program. Through this program, UVa in implementing many actions that will lead to improved stormwater quality. More information on this program can be found under the Regulations page of this web site.
- Stormwater Master Planning – UVa manages stormwater using two regional plans that incorporate the entire watersheds of both Meadow Creek and Moores Creek. Through this master planning, the impacts to these creeks caused by even the smallest development on the UVa campus can be anticipated and remediation planned before the project is constructed.
- SPCC Plan – under the UVa Spill Prevention Control and Countermeasures plan, UVa has upgraded all petroleum storage and handling equipment and procedures to reduce and eliminate spills and leaks of petroleum products to the environment thus reducing the chances of petroleum products being washed from the UVa campus during storm events.
- Oil-Water-Sediment Controls – UVa has installed oil-water-sediment filters at parking garages and at the UVa bus depot. These devices remove much of the oil and sediment contaminants from stormwater before it leaves these facilities.
- Daylighting streams – reverse the negative effects caused by development, which often placed streams in underground pipes or culverts. The piping of streams destroys plant and animal habitats, which alters the balance of the ecosystem and negatively affects water quality.
- Creating wetlands – wetlands provide a primary habitat for animals and aquatic plants. Wetlands improve water quality with natural pollutant removal mechanisms that results from the complex ecosystem that flourishes there.
- Creating ponds – Ponds act as retention areas which can store large volumes of water for extended periods of time. Ponds allow for the removal of pollutants, the settling of suspended particles, and provide habitats for plants and animals.
- Planting native wetland species – natural wetland plants promote ecological activity and provide habitat for animals and beneficial microbes. These native plants aid in the removal of pollutants, improve water quality, and improve the aesthetics of the University.
- Creating floodplains – floodplains allow additional water storage and water quality improvement during large storm events. A gently sloping floodplain along a stream or wetland acts as a buffer between developed and natural areas and provides space for recreation.
- Incorporating aquatic benches – aquatic benches allow for increased diversity within the wetland and pond systems. Benches allow various depth zones within the water for various species of plants to grow. The benches also provide animal habitat, conceal water level fluctuations, and enhance safety.
- Creating vegetated buffers – buffers provide open space between the functioning drainage system and the developed University grounds. These spaces protect the drainage system from everyday human activities and will allow upland plants to be planted to increase the biological diversity of the system.
- Enhanced Infiltration – by increasing the infiltration of stormwater into the subsurface, groundwater is recharged and the volume of runoff is decreased. This is particularly beneficial when runoff from impervious areas such as parking lots and roof tops can be directed to infiltration galleries.
- Detention Basins – detention basin are used in several area to temporarily retain stormwater runoff. While this technique does not generally improve water quality it does serve the purpose of reducing the high flow events in local streams.
- Construction Site Management – UVa has stepped up efforts to control stormwater originating from construction sites. Construction site can be the major source of sediment from a local area. Routine inspections are conducted to ensure sediment and erosion control measures are being property implemented.
Other ways to manage stormwater:
Permeable parking spaces allow rainwater to infiltrate directly into the ground rather than running off directly into storm sewers and waterways. When stormwater runs off over a paved surface, such as a parking lot, it picks up any contaminants found on the surface of the paved area. On traditional asphalt parking lots, oil and grease drips from cars are washed way during rain events and flow untreated into local waterways. Permeable parking areas allow this runoff to infiltrate directly into the ground where natural processes can break down the pollutants thereby minimizing the impacts on nearby streams.
Permeable parking spaces allow for stormwater to infiltrate into the ground rather than running off the surface.
The combination of concrete and rocks allows for water to infiltrate while providing the reliability of traditional asphalt parking lots.
To report an illicit discharge, spill, or unusual water condition call 982-4911!
Contact EHS with stormwater related questions or comments at storm-water@virginia.edu.
EHS Stormwater website questions or comments should be directed to Jess Wenger at jsw6d@virginia.edu or 982-5540.
