Public Works

Stormwater Management

Municipal Separate Storm Sewer System

In a watershed-based approach to urban stormwater management, the Municipal Separate Storm Sewer System (MS4), which includes both structural (e.g., pipes, inlets, and outlets) and natural drainage ways, serves multiple functions: 

  • The Collection, Conveyance, and Storage of Stormwater Runoff
  • Areas for Recreation and Open Space
  • Conservation of Biodiversity

While all of these aspects are important and need to be included as part of a comprehensive stormwater management program, the hydraulic function of the overall MS4 takes precedence.

Federal and State Regulations

The U.S. Environmental Protection Agency (EPA), as part of the National Pollutant Discharge Elimination Systems (NPDES) Program, has passed regulations and requirements for managing potential contamination of stormwater. Within Colorado, the Colorado Department of Public Health and Environment (CDPHE) has developed regulations for implementing and complying with these Federal Stormwater requirements.  These State requirements are managed through the Water Quality Control Division of the CDPHE. The City is responsible for stormwater control within the city limits and is required to comply with the requirements of the associated Stormwater NPDES Permit that is administered through the CDPHE.

Stormwater Phase II Permittee

Under the EPA and CDPHE Stormwater Phase II Program, the City of Lone Tree is a Stormwater Phase II permittee under the State General Stormwater NPDES General Permit COR0800000 and the City-specific Permit COR-080016. The first version of this Permit became effective March 2003, and as such, the City of Lone Tree has taken the lead role in stormwater and drainage way management within the City. This includes coordination with respect to additional requirements for development in those areas within the City which are tributary to the Cherry Creek watershed basin.

Lone Tree’s Commitment

Lone Tree is committed to taking a proactive role in managing stormwater runoff within the City as part of the overall goal of providing quality services to its citizens. The third version of Permit COR-080016 became effective on July 1, 2016. A link to the City’s current MS4 Program Description Document is provided below and the City invites the public to review and provide input on all aspects of the City’s program.

Additional Stormwater Information