- Why is Stormwater Runoff a Problem?
As we cut woodlands, clear land, pave roads and parking lots, and construct houses and buildings, we change the permeability of the ground. Falling rain has fewer places to soak in gradually. Runoff on hard surfaces occurs faster and in greater volumes. Increased stormwater runoff can worsen flooding, erosion, and water pollution and destroy stream habitat.
- What are Stormwater BMP (Best Management Practice) Facilities?
Stormwater BMP facilities are engineered facilities that are designed to convey storm runoff, remove pollutants and to control flow rates. These facilities include pipes, ditches, swales, filters, ponds, underground tanks and vaults. These systems are specifically designed to capture, treat, store and then slowly release stormwater runoff downstream or into the ground.
- What are the Benefits of Stormwater BMP Facilities?
In addition to helping prevent flooding and erosion, Stormwater BMP facilities help to protect water quality by incorporating features that filter or remove sediments, excess nutrients and toxic chemicals.
- How Do Detention and Retention Facilities Work?
A detention pond stores accumulated stormwater runoff and slowly releases it downstream. A flow control structure regulates the release rate of the stored water. Some detention ponds are combined with water quality treatment ponds (i.e., wetponds) which are intended to have some water in them on a permanent basis.
A retention or infiltration pond collects stormwater and allows the water to soak into the soil. This infiltration process helps recharge groundwater.
Underground tanks and vaults function the same way detention ponds do: storing rainwater from a storm and then slowly releasing the water downstream. Tanks and vaults can be located underground in the road right-of-way, parking lots, easements on private property, or any designated tract of land. Infiltration tanks or pipes are located underground and release water into the soil where it is absorbed.
- What is a Water Quality Facility?
Water Quality facilities use, singly or in combination, vegetated swales, settling ponds or vaults, sand filters, compost filters, oil-water separators and constructed wetlands. These facilities protect water quality by removing pollutants. Water Quality facilities are often combined with R/D facilities for more efficient use of space.
Who Maintains Stormwater Facilities?
Many stormwater facilities in Henrico County are owned and maintained by the County, and some are privately owned and maintained. Henrico County maintains facilities that are in road right-of-way and county-owned tracts. Generally, these facilities serve public roads and single-family subdivisions. Facilities serving multi-family and commercial development are on private property, and are typically owned and maintained by the property owners.
Facilities are inspected periodically to ensure they are safe and function properly. The County also relies on citizens to report problems that arise between inspection dates.