The City’s Task
The City of El Monte (City) is developing a Stormwater Urban Master Plan (SWMP or Master Plan) to develop a roadmap to improve water quality, consistent with the National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System Permit (MS4 Permit), Order No. R4-2021-0105, and the approved Watershed Management Program (WMP). The Master Plan will provide the City with a plan and schedule for future project implementation to address stormwater regulatory requirements and improve water quality. The Master Plan will incorporate comments received during public outreach efforts, including workshops and study sessions. Project goals are as follows:
- Identify and assess potential projects to capture and retain urban runoff associated with dry- and wet-weather within the City
- Provide the City with a plan and schedule for future project implementation to address stormwater regulatory requirements, as defined in the City’s WMP and MS4 Permit
- Enhance water quality locally and in downstream water bodies
- Reduce local dependency on imported water through groundwater recharge
- Educate local communities through education and outreach
- Leverage available funding sources
- Reduce localized flooding
- Provide increased green space and public amenities
- Provide community enhancements through surface restoration and improvements
Identify Projects
Prevent Flooding
Capture & Clean H2O
Revitalize Environment
The City’s Vision
A Master Plan is being developed to identify and assess potential projects to capture and retain urban runoff associated with dry- and wet-weather within the City, and to meet the reduction targets for bacteria and metals corresponding to the commitments made in the WMP. The Master Plan will provide the City with a plan and schedule for future project implementation to address stormwater regulatory requirements, as defined in the City’s WMP and MS4 Permit.
Project Background and Goals
The NPDES MS4 Permit was adopted by the Los Angeles Regional Water Quality Control Board (LARWQCB) on July 23, 2021, and became effective on September 11, 2021. As a Permittee, the City is required to individually or collaboratively develop a WMP to identify and implement strategies, control measures, and Best Management Practices (BMPs) to address Water Body Pollutant Combinations (WBPCs) and comply with Total Maximum Daily Loads (TMDLs). The City developed an individual WMP in June 2014, which was approved on August 12, 2015. The approved WMP was subsequently updated in September 2017 and June 2021. The City’s WMP identifies a percent reduction required for particular pollutants in associated watersheds. The following were identified as targets:
- Average reduction for metals in Los Angeles River Watershed: 47% (zinc is limiting/priority pollutant)
- No reductions are needed for lead in the San Gabriel River Watershed (meeting targets)
- Average reduction for bacteria (City-wide): 90% (while WMP mentions that analysis is not as clear for bacteria)
- Los Angeles River bacteria TMDL deadlines: 2028 for dry-weather and 2037 for wet-weather
- San Gabriel River bacteria TMDL deadlines: 2026 for dry-weather and 2036 for wet-weather
Project Progress
As indicated above, a Master Plan is being developed to identify and assess potential projects to capture and retain urban runoff and improve water quality. The steps highlighted in the Project Phases website section are being followed as part of a step-by-step approach to develop the Master Plan. Potential project sites have been identified and concept development is underway. The Master Plan is expected to be developed by late 2024.