Stormwater Program Management

The Stormwater National Pollutant Discharge Elimination System Phase II program was created under the Federal Clean Water Act. The program's goal is to increase the water quality of local water bodies by controlling or improving the water quality of stormwater runoff from urban areas.

The program
  • Has financial penalties for noncompliance - up to $25,000 per day if it is determined there is criminal intent.
  • Is administered nationwide by the Environmental Protection Agency and, within Colorado, by the Colorado Department of Public Health and Environment.
  • Is federally mandated and unfunded.
  • Requires owners or operators of Municipal Separate Storm Sewer Systems designated by the state to obtain permit coverage for stormwater discharges to state receiving waters.
As an integral part of the Town of Castle Rock's vision of providing its residents with the highest quality services at the best value, the Stormwater Program priorities are:
  • Safeguard the public welfare through the proper collection, conveyance and storage of stormwater runoff in a non-damaging and
    non-life threatening manner.
  • Ensure compliance with all applicable water quality regulations related to stormwater runoff to the maximum extent practicable.
  • Ensure that all Town municipal separate storm sewer system (MS4) facilities are functioning and maintained to the maximum extent practicable.
  • Protect the overall water quality of the Town's water resources.
  • Provide healthy and diverse natural habitats for flora and fauna in applicable drainage-ways and Town open spaces.
  • Continue to implement programs to control sediment from construction activities, nutrient loading from urban areas, and phosphorus in the Cherry Creek Reservoir basin.
Goals and requirements
Designated entities, such as the Town of Castle Rock, must file a permit application for coverage under the state’s General Stormwater Discharge Permit System. The permit application must include a description of programs or minimum control measures developed to address each of the following areas:

Public education and outreach
  • Increase public knowledge of local water quality problems caused by urban runoff in order to maintain public support for local stormwater quality programs.
  • Inform businesses and the general public about the impacts of illegal discharge and improper waste disposal.
Public participation / involvement
  • Reach out to residents to improve awareness and achieve program compliance.
  • The distinction between the two programs is that public participation / involvement provides a conduit for citizens to participate in the development and implementation of the publicly funded stormwater program.
Illicit discharge detection and elimination
  • Reduce the frequency and environmental impact of illicit discharges in which pollutants are intentionally or accidentally discharged into the storm sewer system.
Construction site stormwater runoff control
  • Reduce, to the maximum extent practicable, sediment and other construction-related pollutants from entering the municipal separate storm sewer system.
  • Require, review, inspect and enforce proper management practices and material disposal on construction sites.
Post-construction stormwater management
  • Implement planning procedures and enforcement mechanisms to reduce, to the maximum extent practical stormwater impacts resulting from areas of new development and significant development.
Pollution prevention / good housekeeping
  • Reduce, to the maximum extent practicable, the amount and type of pollution that is generated by municipal operations or from municipally-owned property.
Because it is located within the Cherry Creek Reservoir Basin, Castle Rock has more stringent permit requirements that have the ultimate goal of protecting the water quality of Cherry Creek Reservoir.

Program costs
In an effort to gain efficiencies and reduce overall program costs for development, implementation and administration, Castle Rock staff has been coordinating its permitting efforts with other designated Douglas County and Cherry Creek Basin entities (e.g., Douglas County, Town of Parker and the City of Lone Tree, among others). Implementation and sustaining program costs for the Stormwater Phase II permit are estimated at $150,000-$200,000 per year.