The SMC California LID Evaluation and Analysis Network (SMC CLEAN) is designed to understand the effectiveness of Low Impact Development (LID) and Green Stormwater Infrastructure (GSI) BMPs. The mission of SMC CLEAN is to develop a thorough understanding of the effectiveness of LID/GSI BMPs in California both in the short term for use in calibration of watershed programs and the long term for modification of LID/GSI design, construction, and maintenance, through coordination with project partners and others performing LID/GSI monitoring and serving as a clearing house for LID/GSI monitoring information, developing targeted LID/GSI research questions and performing targeted LID/GSI monitoring based on these questions, analysis of LID/GSI monitoring data, and recommendations for the design, construction, maintenance, and monitoring of LID and GSI.

Technical Advisory Committee

The purpose of the Technical Advisory Committee is to provide technical expertise and input in the development and implementation of the SMC CLEAN Work Plan. The make‐up of the TAC includes MS4s, regulatory agencies, the environmental community, the development community, the academic community, industry, and other LID/GSI experts that are engaged in the implementation and monitoring of LID/GSI in California. The TAC represents a good cross section of those experts involved in LID/GSI in California and represents a significant amount of the LID/GSI knowledge and experience in California. The TAC has helped to identify potential research questions and provided input on the SMC CLEAN targeted research questions, provided input on the development of the Work Plan, assisted with developing branding for the SMC CLEAN project, assisted with identification of project partners, reviews and provides comments on the SMC CLEAN work products, and attends SMC CLEAN TAC meetings. SMC CLEAN TAC member Arlene Chun, San Bernardino County Stormwater Program, is the SMC Contract Manager for the SMC CLEAN Project and SMC CLEAN TAC member Chris Crompton, Orange County Public Works, help lead the effort for the development of the SMC CLEAN project.


The SMC CLEAN project is led by:

Ongoing Collaboration

A main goal of SMC CLEAN is to coordinate with others evaluating the effectiveness of LID and those

performing LID monitoring. SMC CLEAN coordinates with partners to research and evaluate LID

monitoring data. The primary purpose of collaboration with the project partners is to obtain LID monitoring information and to help to coordinate LID monitoring and use of the SMC CLEAN monitoring protocol.  The SMC CLEAN is engaged in ongoing collaboration with municipalities, academic institutions, SCCWRP, non-governmental organizations, regulatory agencies, and international partners. 

Data Research

The SMC CLEAN project has an ongoing effort to obtain data and other information related to the monitoring and effectiveness of LID and GSI. The initial effort focused evaluation of the existing literature, resources, and data to help identify the SMC CLEAN targeted research questions.  Subsequent efforts have been focused on obtaining LID/GSI monitoring data and related meta data related to the monitoring of these systems. 

Targeted Research Questions

Discussions with the SMC CLEAN TAC identified two primary needs associated with the project. The first is a short term need for a quantification of LID/GSI performance in Southern California, needed for use in providing empirical data to calibrate estimates for compliance measures such as the recently developed watershed programs (i.e. EWMPs, WQIPs, etc.) and their associated watershed/water quality models (i.e. RAA, RAS). The second is more of a long term need to serve as collaboration entity and clearing house of LID/GSI monitoring data in order to understand the effectiveness of various LID/GSI BMPs overtime and understand how the differences in design, construction, and maintenance affect their performance. The result of the discussions with the TAC was the development of the SMC CLEAN Targeted Research Questions, which are provided in a link below.

LID/GSI Monitoring

The SMC CLEAN is actively engaged in LID/GSI monitoring of several bioretention/biofiltration systems and is assisting project partners with monitoring of their bioretention/biofiltration systems. The intent of the monitoring activities is to support answering the SMC CLEAN targeted research questions.  As part of the LID/GSI monitoring the SMC CLEAN developed a Standard LID Project Data-Information List that provides a list of the meta-data that should be collected to understand the performance of LID/GSI BMPs. Additionally, as part of the LID/GSI monitoring the SMC CLEAN developed the SMC CLEAN LID/GSI Monitoring Protocol that provides a standard protocol for the monitoring of LID and GSI systems. 

Data Analysis & Recommendations

The SMC CLEAN involves a process to analyze and summarize existing and new monitoring data obtained as part of the project.  The monitoring data obtained as part of the SMC CLEAN efforts will be analyzed to begin to answer the short-term targeted research questions for use in calibration of watershed programs.  Recommendations are also being developed for a long-term SMC CLEAN effort to help answer the long-term research questions for the modification of LID/GI design, construction, and maintenance to enhance performance.  As part of the development of recommendations the SMC CLEAN updated the SoCal LID manual and developed  the LID & GSI Construction, Inspection, Maintenance, and Monitoring Guidance Manual, which is a companion manual to the SoCal LID Manual.   

SMC CLEAN Work Products

  1. Work Plan
  2. Targeted Research Questions
  3. Standard LID Project Data‐Information List
  4. Monitoring Protocol
  5. Updated Southern California LID Manual
  6. LID & GSI Construction, Inspection, Maintenance, and Monitoring Guidance Manual