Stormwater Programs

The 7 MS4 Programs

CDOT is required to comply with the requirement of the CDOT Municipal Separate Storm Sewer System (MS4) permit. CDOT's MS4 permit authorizes discharges from the municipal storm sewer system within the permit area. The permit requires CDOT to use control measures to prevent or reduce the discharge of pollutants to state waters. The permit does this by requiring CDOT to comply with seven MS4 programs. CDOT has several different programs to make sure the amount of pollutants being discharged is reduced, as part of the permit that allows discharges from the roadway storm drain system. These include: 

Construction Sites

The MS4 permit requires CDOT to implement a program to reduce or prevent the discharge of pollutants to the MS4 from covered construction activities. The requirements include assuring adequate design, implementation, and maintenance of Control Measures at CDOTs construction sites.

Illicit Discharges

The Illicit Discharge Detection and Elimination  (IDDE) Program requires CDOT implement a program to detect and remove (or advise the discharger to the MS4 to obtain a separate CDPS permit for) illicit discharges and improperly disposed materials into the MS4.

Industrial Facilities 

CDOT requires all facilities that discharge stormwater into CDOT's storm drain system to obtain a specific authorization. The program prioritizes education to promote minimization of pollutants in the stormwater that the facilities are contributing to the system.

Public Education and Outreach 

CDOT must implement a public education program to promote behavior change by the public to reduce pollutants in discharges from the MS4. CDOT conducts a variety of outreach activities for employees and the public. Outreach activities include brochures, fact sheets, posters, newsletters, workshops, conferences, and this website.

Permanent Water Quality (PWQ)

This program is required under CDOT's Municipal Separate Storm Sewer System Permit MS4). Each CDOT Region is responsible for evaluating new construction and redevelopment sites in the CDOT MS4 permit area to determine if stormwater controls are required. These controls are referred to as Permanent Water Quality Control Measures (PWQ CM) or permanent Best Management Practices (BMP).

Pollution Prevention and Good Housekeeping 

CDOT prioritizes minimization of pollutants in stormwater by developing runoff control plans for maintenance facilities, requiring the proper application of herbicides, pesticides and fertilizers, maintaining permanent BMPs, and operating public streets, roads, highways, and parking lots to promote both safety and stormwater quality protection.

Wet Weather Monitoring  (WWM)

CDOT assesses wet weather impacts from
highways and the performance of control measures
used to control stormwater discharges.