Roadside swales (JPG) are shallow grassed or vegetated channels that capture, detain and treat road runoff and convey larger flows. The captured water is infiltrated to the ground to recharge the water table and provide base flows for streams.
Rain gardens (JPG) are concave landscaped areas where runoff from roofs or paving is captured, treated and detained before being infiltrated into the soil below. Vegetation helps to filter out contaminants. Rain gardens are designed to have an aesthetic appeal as well as a stormwater function.
Rain barrels (JPG) collect rainwater that lands on your roof so that it can be used to water plants, lawns and gardens. Water that enters the ground rather than a storm pipe helps to maintain base flows in nearby creeks. Using a rain barrel also helps to conserve our drinking water supply by reducing the amount of tap water you use.
On-Site Infiltration Trenches
On-site infiltration trenches (JPG) collect the water from your perimeter drainage system and roof and return it to the ground rather than send it to a storm pipe. The infiltrated water recharges the water table and provides base flows for streams. A slower return of water to the creeks reduces erosion and damage to aquatic habitat.
Roadside Infiltration Trenches
Roadside infiltration trenches (JPG) collect runoff from the road. The water is collected in an underground trench ground where it can be slowly infiltrated to the soil to recharge the water table and provide base flows for streams.
Pervious paving (JPG) is a surface layer that allows rainfall to percolate into an underlying reservoir where it can be stored and slowly infiltrated to the ground. The surface can be porous asphalt or concrete, pavers, or grid structures.
Water Quality Ponds
The purpose of water quality treatment is to clean stormwater flows to an acceptable level for fish prior to discharge into receiving waters. In order to meet water quality criteria, runoff from roadways, lanes, driveways, sidewalks and parking lots should be treated using rainwater management source controls.
Regional water quality ponds (JPG) are used to make up for short falls in areas where source controls cannot fully meet the water quality treatment targets.