Welcome to the State Water Resources Control Board Welcome to the California Environmental Protection Agency
Governor's Website Visit the Water Board Members Page
My Water Quality
Performance Report
Storm Water Program - STORMS

STORMS - Strategy


You may provide feedback on the Storm Water Strategy by submitting the STORMS Feedback Form.

Project 3c: Assess Municipal Storm Water Program Monitoring and Effectiveness

Important, readily achievable



Project Objective:

Identify monitoring and effectiveness assessment approaches that efficiently generate information used for adaptive management and improvement of the local municipal storm water programs regulated by Water Board requirements.


The result of the project is a data and information management approach that will inform Water Board Storm Water Program management decisions, improve program effectiveness, and maximize water quality-based outcomes. After first identifying data and information needs, explore traditional water quality monitoring and new measures of program effectiveness, such as surrogate measures for discharge and receiving water quality (leveraged with efforts already undertaken by stakeholders). Develop methodologies and tools for answering high-priority monitoring and effectiveness assessment questions, such as: (1) how and where compliance with receiving water limitations should be assessed; (2) how to estimate baseline pollutant loads; (3) how to determine relative spatial risks to receiving water quality; and (4) how to quantify the expected load reduction associated with water quality improvement projects. Develop training materials and statewide workgroups to set up implementation, training, and troubleshooting.


Significant funds are spent annually on storm water monitoring and effectiveness assessment; however, the work to date has in some cases been limited in guiding program implementation. Accordingly, reduced costs and increased utility of monitoring and effectiveness assessment is needed. As opposed to past complex techniques, simple models can yield valuable information to support short-term and long-term storm water program decisions and priorities. Use of simple, spatially-based pollutant load and reduction information will support identification and prioritization of water quality actions. For example, the Central Coast Regional Board is developing a spatial approach to estimate pollutant loads and load reductions to provide a simple visual way to identify and prioritize areas for water quality improvements. This work builds from earlier Lahontan Regional Board staff efforts to provide a useable, transparent, and scientifically-credible tool to estimate baseline pollutant loads, determine relative spatial risks to receiving water quality, and quantify the expected load reduction associated with water quality improvement actions. Rather than attempting to model multiple pollutant types, this methodology uses credible and effective representative parameters (i.e., total suspended solids and volume) to create a ranking of municipal catchments in terms of relative risk to the receiving water. The result is information that serves as an effective communication tool between Water Board staff and municipal representatives.



Products and Timelines:

3 Years: Develop technical guidance document that identifies useful data to collect for storm water program effectiveness analysis, and how to report the water data and information on water quality program effectiveness to drive the best responses and management actions. Develop tools, including guidance on: (1) assessing receiving water limitations; (2) estimating baseline pollutant loads; (3) determining relative spatial risks to receiving water quality; and (4) quantifying the expected load reduction associated with water quality improvement actions. Develop Item for State Water Board consideration of adoption.

Phase II

Objective 3

Establish Permit Pathways to Assess Storm Water Programs and Meet Water Quality Requirements

Goal 3

Implement Efficient and Effective Regulatory Programs

Project Information

Name Assess Municipal Storm Water Program Monitoring and Effectiveness
Start 2019
Completion 2022
Lead Staff  
Contract Information  
Performance Metrics  

NPDES Storm Water Facilities annual Performance Report