All Municipal Separate Storm Sewer Systems (MS4s) in the watershed have adopted stormwater regulations that set water quality requirements, consistent with Regulation 72, for construction and post-construction of new development and redevelopment projects within their jurisdictions.

Further information on each MS4’s program can be found in their annual reports that are to be submitted to the Division by March 10 (Phase II MS4s) and April 1 (Phase I MS4s).

Initially considered a non-point source, regulated stormwater in the Cherry Creek Basin is governed by Regulation 61 and Colorado Discharge Permit COR080000, which includes program requirements specific to water quality. MS4 Permit Holders in the Cherry Creek Basin have developed programs that go above and beyond minimum requirements for other regulated stormwater in the State.

Further information on each MS4’s program can be found in their annual reports in the links below.

MS4 Annual Reports

• link Arapahoe County
• link Douglas County
• link City of Aurora
• link SEMSWA (City of Centennial)
• link City of Greenwood Village
• link City of Lone Tree
• link City of Castle Pines
• link Town of Castle Rock
• link Town of Parker

Find Out More About MS4s

• link Arapahoe County Splash
  (Arapahoe County, City of Cherry Hills Village, City of Centennial, Cherry Creek State Parks, City of Sheridan, Greenwood Village)
• link One thing is Clear
  (Douglas County, Town of Castle Rock, Town of Parker, City of Lone Tree, Highlands Ranch Metro District, Castle Pines Metro District, Castle Pines North Metro District, Stonegate and Lincoln Park Metro Districts)
• link H2O Jo Informational Video