Stormwater runoff is the water that flows from rain and snowmelt that doesn’t soak into the ground. It is a major environmental concern because it can pick up pollutants such as pesticides, oil, grease, and heavy metals from roads, parking lots, and other surfaces and carry them into waterways, causing water and soil pollution and harm to aquatic life.

During storms, impervious surfaces such as roadways, parking lots, and compacted soils cause accumulated pollutants to flow into storm drains without treatment. This contaminated water then makes its way into our neighborhood streams, rivers, ponds, and lakes. 

Rainwater should naturally soak into the soil to be filtered, but areas that can’t absorb water prevent that from happening. This causes an increase in the volume and rate of polluted stormwater runoff into local waterbodies. As communities grow, they often experience even more stormwater runoff problems. 

Without proper stormwater management, developed areas negatively impact their surrounds by causing a “flash-flood-like” event. Contaminated runoff damages stream channels, pollutes water resources, and causes flooding. The most common pollutant in our water is soil. 

Stormwater from roads and buildings can impact private property, causing safety concerns and landscaping damage. Rainwater damage is often left to citizens to repair, unlike common public infrastructure such as roads, sewers, or electricity. 

Updated Design Strategies

Stormwater management has the approach for both small and large rainfall events, of improving water quality while reducing water quantity. Better site design is the first step to building improved communities. Urban areas with regular rainfall should be designed to:

• preserve natural drainage in open spaces
• reduce flow speed of additional stormwater
• reduce pollutants
• reduce flooding
• reduce impervious surfaces