County of Boulder

Regulatory Compliance

The Stormwater Quality Program assures compliance with all state and federal water quality regulations related to stormwater. The City of Boulder's municipal separate storm sewer system operates with a permit from the Colorado Department of Public Health and Environment. In compliance with requirement Part I.D.1.b of the Phase II MS4 permit, the city’s Program Description Document is publically available for review and comment by contacting the Stormwater Quality Program. 

The permit sets requirements related to six minimum control measures:

  • public education and outreach;
  • public participation;
  • illicit discharge detection and elimination;
  • construction site runoff control;
  • post-construction runoff control; and
  • pollution prevention and good housekeeping.

In addition to stormwater regulations for municipalities, federal regulations require certain industrial facilities to obtain a stormwater discharge permit. City-owned facilities such as the Wastewater Treatment Facility and the Boulder Municipal Airport are included in these current Industrial Pretreatment regulations. Stormwater discharges associated with construction activities are also required to obtain a permit.

Boulder County Storm Drainage Criteria Manual

Section 1200 Detention and Permanent Water Quality

This section presents the criteria for design and evaluation of all detention and water quality facilities
for Boulder County. The main purpose of a detention facility has historically been to store the excess storm runoff associated with increased basin imperviousness and discharge this excess at a rate similar to the rate experienced before development. In recent years, detention facilities have also frequently been viewed as a unique opportunity to improve the water quality of runoff coming from developed areas. This runoff typically carries higher levels of nitrogen, phosphorus, and sediment that can damage the ecosystems of the natural streams downstream of the development. This section discusses detention both with and without a water quality component; water quality facilities located outside a detention basin, including proprietary facilities; and when detention and water quality are required.

1203.3 Maintenance of Detention Facilities and 1204.5 Maintenance Requirements of Permanent Water Quality Treatment

The performance of detention facilities is extremely sensitive to a lack of maintenance. Detention facility outlets in particular must be regularly maintained to ensure the basins meet the requirements of Colorado water law and do not detain water longer than allowable. If detention is to be constructed, Boulder County requires an enforceable maintenance agreement to be in place before issuing any applicable local permits. The agreement must include the party responsible for maintaining the facility,inspection frequency, and proposed maintenance activities.


Boulder City Stormwater Quality Overview

Boulder City Stormwater Master Plan

Boulder County Storm Drainage Manual