Storm Water Management - Town of Cedarburg

NPDES PERMIT

In 2024, the Town of Cedarburg received a Non-point Pollution Discharge Elimination System (NPDES) permit from the Wisconsin Department of Transportation. This is a permit with the goal of reducing pollution, mainly the amount of dirt, sand, and other debris, called total suspended solids, that is collected in rain water runoff and eventually gets to Cedar Creek or the Milwaukee River. Several other communities along Cedar Creek and the Milwaukee River are under similar permits. As part of the permit, the Town updated their stormwater quality management plan, which outlines requirements for the Town, private development, and even individual landowners to control the pollutants in runoff.

There are three components to the stormwater quality management plan.

The first component is a post-construction stormwater management plan (Ordinance 2023-11). This plan is generally required when a development or improvement will have a large area of impervious, or non-absorbing, surfaces such as building roofs or paved parking lots after construction. If a development will result in more than 10% of the site being impervious a management plan is required (see reference guide). This plan is designed to reduce the amount of rain runoff from site that equals the amount of runoff if the site was completely left undeveloped. The most common way to reduce this runoff is to create a pond that will hold rain runoff and release it to ditches or streams at slow rate. Holding the water for a time allows the total suspended solids to settle out and let clean water into the ditches, streams, wetlands, and lakes. Another method to control runoff is to construct a rain garden. These gardens are small shallow ponds often planted with native Wisconsin plants. The gardens will collect water from downspouts, sump pumps, or parking lots, hold the water and let it seep into the ground. This method purifies the runoff through filtration and can help regenerate groundwater. The Town constructed a demonstration rain garden at Town Hall. A third method for controlling stormwater is through the use of rain barrels. These barrels are placed at the discharge point of a downspout to collect the runoff from the roof. The water is then recycled, used to water lawns, and gardens. Rain barrels may be ordered through Ozaukee County.

The second component to the stormwater management plan is to control sediment that runs off from construction sites. To accomplish this almost all construction requires an erosion control permit. This permit defines the methods that will be used to control erosion from a construction site and lists a plan to maintain the controls (see reference guide). Anyone doing work on their property that involves grading or moving ground, should contact Town Hall to check if an erosion control permit is required.

The third component of stormwater management is to reduce and ultimately eliminate toxic or environmentally harmful elements, known as illicit discharges (Ordinance 2023-9), from getting into the lakes, wetlands, and streams. Examples of illicit discharges are chemical spills, gasoline, oil, and antifreeze, soap and detergent, and liquid food wastes, such as milk and cooking oil. Town staff does periodic surveys of key discharge points near wetlands, streams, and lakes to check for these discharges. If they are found, the Town will try to determine where the illicit discharge came from and will levy fines and possibly press criminal charges on those responsible. This is one area where you can assist the Town. If you notice water in your ditch looks milky, has a rainbow-like sheen on the surface, or there is a strong odor from the ditch, please contact Town Hall at (262) 377-4509.

The illicit discharge ordinance also requires new or replaced sump pump and roof drain outlets to be at least ten feet from a property line. Ditches and drainage ways generally follow property lines and keeping the discharge point back from these drainage ways allows for some removal of suspended solids and prevents erosion of and sediment build-up in the ditches.