Storm drainage systems include items such as pipes, street/curb inlets, ponds, and even natural channels. Municipal stormwater drainage systems are sometimes referred to as Municipal Separate Storm Sewer Systems (MS4s). These systems are monitored by the National Pollutant Discharge Elimination System (NPDES), which is controlled by the EPA. The EPA set up the NPDES as part of the CWA. The City of Evans falls under what is referred to as the Stormwater Phase II portion of this legislation as noted above.
The major stormwater outfall for the City of Evans is the South Platte River which is joined to the west by the Colorado Big Thompson River at the two rivers’ confluence. There are other municipalities and individuals downstream from the City of Evans that depend on the South Platte River for their public drinking water and irrigation. In order to help increase the quality of the stormwater that the City of Evans releases into the South Platte River, we need help from the citizens. Property owners should make a conscious effort to store and dispose of waste such as motor oil, anti-freeze, and other hazardous materials properly. We can also help by reducing our dependence on lawn fertilizers, pesticides, and herbicides. Another major contributor to stormwater pollution is sediment. Most sediment comes from the erosion of un-vegetated lands such as that found on construction sites and farmland.