Runoff, Erosion, and Sediment Control
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2 |
Minimizes quantity and rate of stormwater runoff, which reduces site erosion and potential contamination of water bodies |
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4 |
One to three months to implement no- and low-cost tactics, six to 12 months to establish new plantings, and one to two years for longer-term site upgrades |
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3 |
Vegetation selection and planting and installation of permeable surfaces |
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FAC, BPO |
Stormwater runoff can cause soil erosion and sedimentation of local waterways. Erosion results in loss of topsoil, which regulates water flow and is essential for plant life. Topsoil loss may lead to increased need for fertilizers and pesticides to maintain plant material. In turn, the use of increased fertilizers and pesticides pollutes rivers, lakes, and oceans. Site sediment also pollutes and degrades aquifers and local waterways by adding high concentrations of total suspended solids and toxins.
Runoff prevention strategies are particularly important to implement at posts that experience large storm events or high volumes of annual precipitation. Existing erosion control measures should be protected and reinforced to prevent breaches and damage during new construction or major renovations to buildings, landscapes, or hardscapes. Strategies may include temporary installations of hay bales around inlets, silt fences at the boundary of disturbed soils, and gravel at construction vehicle entrances and exits.
Runoff from erosion has impacts far from the site of origin. The sediment produced can clog fish gills and suffocate aquatic habitats.10
Consider the following landscape plan components to reduce the quantity and speed of runoff and minimize associated erosion:
- Use compost and mulch in planted areas to protect exposed soils.
- Add small-scale bioretention areas, such as planter boxes or tree wells.
Longer-term initiatives for on-site stormwater retention and detention include:
- Rainwater harvesting for larger-scale irrigation or potable water use (see Water: Rainwater Harvesting)
- Site regrading to eliminate steep slopes and retain water on-site
- Natural bioswales to treat runoff passively instead of concrete curbs, gutters, and culverts, which concentrate and exacerbate site runoff
- Biofiltration to treat runoff passively
- Replacement of hardscape with permeable surfaces, such as gravel or pervious pavement, to increase infiltration and recharge groundwater.
- Installation of vegetated roofs and rain gardens to control runoff
Bioswales, or ‘rain gardens,’ passively treat stormwater runoff
