A rain garden is a garden which takes advantage of rainfall and stormwater runoff in its design and plant selection. Usually, it is a small garden which is designed to withstand the extremes of moisture and concentrations of nutrients, particularly Nitrogen and Phosphorus that are found in stormwater runoff. Rain gardens are sited ideally close to the source of the runoff and serve to slow the stormwater as it travels downhill, giving the stormwater more time to infiltrate and less opportunity to gain momentum and erosive power.
A green roof is a roof of a building that is partially or completely covered with vegetation and soil, or a growing medium, planted over a waterproofing membrane. Benefits of a green roof include: reducing heating and cooling loads on a building, increases the roof life span, reduce stormwater runoff, and filter pollutants. A concentration of green roofs in an urban area can reduce the city’s average temperature during the summer months.
Permeable Paving Systems
Permeable paving is a range of materials and techniques for paving roads, parking lots and walkways that allow the movement of water and air around the paving material. Although some porous paving materials appear nearly indistinguishable from nonporous materials, their environmental effects are qualitatively different. Whether porous asphalt, concrete, paving stones or bricks, all these pervious materials allow precipitation to percolate through areas that would traditionally be impervious and instead infiltrates the stormwater through to the soil below.