Protecting water quality
As development occurs, runoff from rainfall and snow melt passes through urbanized areas before reaching natural waterways. The stormwater utility manages this urbanized runoff through water quality treatment practices, storm sewer conveyance systems and flood control facilities. 

The stormwater utility is funded through monthly services charges based on an urbanized footprint calculated for each account. New growth is charged a development impact fee to account for downstream system improvements. This fee covers the cost of operation, upgrades, maintenance and improvements of the Town’s storm drainage facilities.


The following services are provided to the community:
  • Regional stormwater system planning
  • Major drainageway system improvements
  • Storm sewer system maintenance
  • Water quality protection
  • Floodplain management
What's new in stormwater?
Stormwater detention notification requirements
On August 5, 2015, new statewide requirements related to stormwater detention facilities went into effect. Under Colorado Revised Statutes (CRS) 37-92-602 (8), all new stormwater detention facilities require notification to email distribution lists maintained by the State Engineer’s Office. All development applications in the Town of Castle Rock that include stormwater facilities must demonstrate compliance with this statute prior to plan approval. For more information visit Code Central.

Flood Insurance Rate Maps
Over the past several years, the Town of Castle Rock has been conducting studies on major drainageway systems. These studies consider current ground topography, development and known problem areas. We are in the process of incorporating these new studies in an update of the communities Flood Insurance Rate Maps (FIRM) and the Flood Insurance Study (FIS) Report. These updates are scheduled to be adopted by March 16, 2016.