MS4 Area

Description This layer was created by the CDOT Water Quality Unit and is updated annually using the 2010 census urbanized areas (non clusters), Cherry Creek Drainage Basin, and the most recent city limits (from DOLA) as listed in the MS4 permit issued August 2015. MS4 (Municipal Separate Storm Sewer Systems) is a conveyance or system of conveyances that is: Owned by a state, city, town, village, or other public entity that discharges to waters of the U.S.; Designed or used to collect or convey stormwater (including storm drains, pipes, ditches, etc.); Not a combined sewer; and Not part of a Publicly Owned Treatment Works (sewage treatment plant). Last Update 2025 Update Frequency Annually Data Owner Division of Transportation Development Data Contact GIS Support Unit Collection Method Projection NAD83 / UTM zone 13N Coverage Area Statewide Temporal Disclaimer/Limitations There are no restrictions and legal prerequisites for using the data set. The State of Colorado assumes no liability relating to the completeness, correctness, or fitness for use of this data.