Council Memo

Presentation of the City’s Stormwater Management Program, Federal and State rules, and current and future program activities


Department:Public WorksSponsors:


  1. Printout
  2. MS4 Presentation to Council

Document Comments

Recommended Action: Presentation for Council information and discussion – no formal action is requested at this time.


Item Summary


The City of Prescott operates a Municipal Separate Storm Sewer System (MS4), which means that the storm sewer and the sanitary sewer are separate systems. The City’s storm sewer system consists of municipally owned streets with drainage systems comprised of a combination of catch basins, curbs, gutters, ditches, manmade channels, and storm drains. Rain, snow melt, and other substances dumped into a street, alley, gutter or storm drain enter the storm drainage system and flow untreated into the nearest creek or lake.

In Arizona, MS4s are regulated by the Arizona Department of Environmental Quality (ADEQ) through the Arizona Pollutant Discharge Elimination System (AZPDES) permit program. In accordance with the AZPDES Small MS4 General Permit, each MS4 is required to prepare and implement a Stormwater Management Program Plan (SWMP). The SWMP must reduce the discharge of pollutants to the “maximum extent practicable”, protect water quality, and satisfy the appropriate water quality requirements of the Clean Water Act. Small MS4s must design into their programs six minimum control measures including: Public Education and Outreach; Public Participation/Involvement; Illicit Discharge Detection and Elimination; Construction Site Runoff Control; and Post-Construction Runoff Control. 


This presentation will give an overview of stormwater regulations, a description of the City’s stormwater program activities, future changes to the permit, and connection to the Watson Lake and Upper Granite Creek Watershed Total Maximum Daily Loads (TMDLs).