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. An overview of the SMC CLEAN is provided in SMC CLEAN Training Module 1 – SMC CLEAN Overview.

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.

SMC CLEAN Team

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.

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. 

The materials used for construction of LID and GI including bioretention systems are extremely important and have a significant impact on their performance, however the quality of the materials used for construction may not be known or documented.  One potential additional area of focus for future SMC LID & GI effectiveness evaluation is the evaluation of the materials that are used for construction of LID & GI systems.  As part of SMC CLEAN Phase I the SMC CLEAN Bioretention Materials & Users Survey is being completed that is intended to provide input as to the quality and protocols being used for assessment of the quality of the materials used in the construction of bioretention systems in California. The results of this survey can be used to formulate a scope for a bioretention materials study that may include column testing of the components bioretention soil media (BSM) sourced from suppliers of BSM materials and testing of identified BSM specifications in the state.

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.   

Training Modules (YouTube videos)

SMC CLEAN Phase I Final Project Report

The SMC CLEAN Phase I Project Report serves as the summary of SMC CLEAN Phase I. In furthering the mission of the SMC CLEAN this report provides an initial understanding of the effectiveness of LID BMPs in California, however more prevalently the report emphasizes the primary finding of SMC CLEAN Phase I, which is that currently there is a lack of existing data, monitoring data and meta data needed to perform the analysis necessary fora thorough understanding of the effectiveness of LID BMPs in California identified in the SMC CLEAN mission. A key finding of the SMC CLEAN Phase I and previous LID effectiveness evaluation work performed by the SMC and its partner agencies, is that long-term monitoring data for LID and GSI projects in Southern California are essential to truly understand the effectiveness of LID and GSI systems in Southern California. This report provides a pathway and process to obtain the monitoring data and meta data to perform the analysis needed to have a thorough understanding of the effectiveness of LID BMPs in California and achieve the SMC CLEAN mission.

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
  7. SMC CLEAN Bioretention Materials & Users Survey 
  8. SMC LID-GI Long-Term Effectiveness Evaluation Needs – White Paper
  9. SMC CLEAN Phase I Final Project Report