View the DRAFT 2021 Annual Stormwater Report for Public Comment here!

Improving Stormwater Management at UNM:


One permit regulates all stormwater at UNM. The Middle Rio Grande Watershed-Based Municipal Separate Storm Sewer System Permit (the MS4 permit) authorizes UNM to release stormwater into the Rio Grande River.

What's in the MS4 name?

"Separate" means that the stormwater system is separated from the sanitary sewer (stormwater flows through storm drains and diversion channels to the Rio Grande, while sewer water flows through sewer pipes to a water treatment plant.) "Municipal" means that outflow system is owned by a state, city, town, village, or other public entity. As the permit holder, UNM is considered the municipality and the regulator for all stormwater within its property.

What’s the point of the MS4?

The purpose of the MS4 permit is to keep the Rio Grande free of pollution. To understand how it does this, it’s important to understand the policy origin of the permit. The MS4 exists as a provision of the Clean Water Act of 1972 (CWA). CWA established a system for the U.S. Environmental Protection Agency (EPA) to regulate the flow of pollutants into U.S. bodies of water under a structure called the National Pollution Discharge Elimination System (NPDES).  While all other NPDES permits must include limitations that ensure a discharge complies with applicable water quality standards, the MS4 is subject to a unique standard. MS4 permit holders must "reduce the discharge of pollutants to the Maximum Extent Practicable” or the MEP. This standard exists because pollutants washing out during a rain event do not originate from a single source and cannot be regulated easily.

What does UNM have to do as an MS4 permit holder?

UNM’s MS4 permit is watershed-based, covering the entirety of the Middle Rio Grande Watershed (Figure 1). The watershed-based approach contrasts with the municipal-based permit, which is limited to the political boundaries of a city or county. UNM is a co-permittee with other cities and tribal groups in the watershed. In total, there are 14 co-permittees in the Middle Rio Grande Watershed – including the City of Rio Rancho and Kirtland Air Force Base. As a group, the co-permittees must work together to improve the quality of stormwater discharged. Each co-permittee holds an individual permit to discharge stormwater into the Rio Grande, and each develops a Storm Water Management Plan (SWMP) to meet the terms of their MS4 permit while also working together to meet the overall goal of improving water quality. Within the SWMP is contained a set of best management practices (BMPs), designed and implemented to reduce stormwater pollution

Figure 1


UNM has three types of plans which cover the management of the MS4 permit.

  1. The Stormwater Management Plan (SWMP) - An overview of the entire stormwater management program
  2. The UNM Illicit Discharge Detection and Elimination Plan (IDDE) - A plan to stop the illicit dumping of pollutants 
  3. The Stormwater Pollution Prevention Plan (SWPPP) - A plan for construction-related pollution on a site-by-site basis. 


The Environmental Health & Safety Department (EHS) provides public education on stormwater through a combination of Welcome Back Days events, advertising campaigns, and the UNM website. Welcome Back Days events include a slideshow, quiz, and giveaway of event materials. EHS runs an annual advertising campaign through KUNM, which focuses on the control of pet waste pollution. The reach of this program is much broader, with a listenership of over 10,000 in Albuquerque. In addition, the department helps administer a physical ad campaign using materials from ABCWUA (Figure 2). 

  Figure 2