County of Boulder

The County of Boulder has enacted a Stormwater Ordinance in order to establish minimum stormwater management requirements and controls to protect and safeguard the general health, safety, and welfare of the public residing in watersheds within this jurisdiction.  The County of Boulder is the permitting authority for all land disturbing activities and requires the land owner to maintain all on-site stormwater control facilities and all open space areas (e.g. parks or “green” areas) required by the approved stormwater control plan. The County of Boulder will only provide construction permits to projects that establish a plan to manage stormwater runoff occurring during the construction process. The County of Boulder, under the NPDES program, also has the authority to inspect properties for noncompliance and can issue a notice of violation (NOV) for any deficiency or infraction onsite. Property owners are responsible for the maintenance of any stormwater facilities or practices located on the property. The County of Boulder has the authority to inspect stormwater facilities and practices in order to ascertain that they are properly maintained and functioning.

Excerpt from 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.

Excerpt from Boulder City Stormwater Master Plan

9.8.1 Operations and Maintenance Program (MCM 5 and 6) 

This section describes the city’s current stormwater O&M program. O&M is included in both MCM 5 and MCM 6 in the 2008 MS4 permit. The section describes standard maintenance of the stormwater system and permanent stormwater BMPs, the stormwater repair and rehabilitation program, and monitoring and sampling of the stormwater system. Permanent BMP Inspection Currently, the city follows a stormwater maintenance schedule for permanent BMPs in the city. Above-ground private BMPs are inspected per state requirements and the responsible party is expected to maintain them. Stormceptors™ and other proprietary BMPs are currently used in the city’s storm drain system, but there is no stormwater maintenance schedule for these or any other city-owned BMPs. Private ponds are inspected and are entered into the city’s database. The city does not perform in-depth inspections of private proprietary BMPs, such as Stormceptors™. Recently, the city implemented a GIS-based asset management tool for tracking city-owned, proprietary, and other BMPs. The city is also trying to better organize and use as-built drawings for city projects. These are good first steps to creating consistency in maintenance and inspection schedules.

Boulder County Resources

Boulder County Stormwater Quality Program

Boulder City Stormwater Master Plan

Boulder County Storm Drainage Manual