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3 <br />CW Stanford "Eco•Classroom" - Stormwater Background Information <br />• Excess nutrients, such as nitrogen, become pollutants in stormwater runoff by <br />promoting algae to grow in surface waters; algae use large amounts of oxygen <br />during their life cycle, especially when they die-off, causing fish kills and other <br />negative impacts; <br />• North Carolina's number one water quality problem is stormwater runoff <br />pollution. <br />Stormwater "Retro-fits" <br />Currently, there is a large amount of impervious surface that ultimately drains to this <br />creek. No doubt the water quality of the stream and the aquatic ecosystem has been <br />adversely impacted. There is grant money available to install stormwater "retro-fits". <br />These are engineered stormwater devices designed to reduce runoff and improve water <br />quality. They can be designed as amenities in addition to being terrific teaching aids. <br />Some of these include: <br />• Rain gardens or bioretention -man made depressions designed to pond <br />stormwater runoff, allowing it to soak into the ground where native plants and <br />other biotic processes help to remove pollutants. Typically water pools less than a <br />day. This slows runoff, reducing erosion and downstream flooding potential. <br />• Stormwater wetlands -designed to permanent pool water capture the "first flush" <br />of runoff and allows wetland plants to filter pollutants. Stormwater wetlands also <br />provide valuable aquatic habitat. Mosquitoes are not a problem since stormwater <br />wetlands provide places for small fish and amphibians that are mosquito <br />predators. This slows runoff, reducing erosion and downstream flooding potential. <br />• Rain harvesting -capturing rainfall is not a new idea. Rural people and farmers <br />used cisterns extensively. Thanks to the drought, capturing rainfall has had a re- <br />emergence. Harvesting rainfall to irrigate landscape areas and athletic fields <br />would not only reduce water usage, it improves water quality. Capturing runoff <br />and slowly releasing it in dry weather as irrigation, allows it to soak into the <br />ground, removing pollutants and reducing erosion and downstream flooding <br />potential. <br />• Riparian Buffers -are anon-structural stormwater management practice. Trees <br />along streams act as "water pumps" removing pollutants from runoff. They also <br />slow down runoff, hold the soil in place which reduces erosion and downstream <br />flooding potential. Trees are aesthetically appealing as well. <br />There are other measures that can be used as well but these are the most common and <br />logical. Using grant money, consulting firms can study, design, and build these measures <br />to meet the needs of the eco-classroom. <br />Page 2 of 4 <br />