The major difference between the drains associated with your household plumbing and the storm drains found in the street is treatment. Water that goes down the drains inside your house is transported through the sanitary sewer system to a treatment facility. At these facilities there are chemicals added and processes completed in order to clean the water prior to releasing it back into the South Platte River. When water enters the storm drainage system it is transported to the river without receiving any treatment, so any trash or pollution that enters this water is transported directly to the river.
Storm drains are for containing stormwater runoff and transporting it to its outfall. The majority of the City of Evans stormwater drainage system is underground. That way, stormwater can be conveyed to the South Platte River without causing flooding or erosion along the way. This also helps keep water off of the streets and intersections to improve traffic safety during storms.
Stormwater can carry trash and harmful pollutants, cause flooding, erode topsoil and stream banks, and destroy marine life habitats. In a rural area with natural ground cover, on average, only 10% of rainwater becomes runoff. The rest is absorbed or evaporates. In an urban area, up to 55% of rainfall can become storm water runoff. This is mainly due to there being a lot more impervious surfaces such as pavement, sidewalks, driveways, and rooftops. Remember, the water and other items that enter the stormwater drainage system do not get treated before being released into the South Platte River.
The stormwater drainage system is a utility. It provides a service to all the residents and some non-residents of the City of Evans. In order to maintain the system and make necessary improvements, we have to add a small fee to your utility bill. This type fee is common in other communities throughout Colorado. The following table includes other Colorado Cities that have stormwater utilities and their single-family residential fees.