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File #: REPORT 16-0558    Version: 1 Name:
Type: Communication Status: Study Session
File created: 9/14/2016 In control: City Council
On agenda: 9/19/2016 Final action:
Title: STORMWATER UPDATE (Environmental Analyst Kristy Morris)
Attachments: 1. Hermosa Beach Greenbelt Infiltration Project.pdf, 2. Hermosa Beach Infiltration Trench Project.pdf, 3. Hermosa Avenue Green Street Project.pdf, 4. SUPPLEMENTAL Stormwater Update Presentation (added 9-19-16 at 430pm).pdf

Honorable Mayor and Members of the Hermosa Beach City Council                                                                         Regular Meeting of September 19, 2016



(Environmental Analyst Kristy Morris)



Recommended Action:


Receive an update on City of Hermosa Beach actions for complying with the 2012 MS4 permit requirements.




The Los Angeles Regional Water Quality Control Board, (Regional Board) adopted the National Pollutant Discharge Elimination System Municipal Separate Storm Sewer System Permit Order No. R4-2012-0175 (MS4 Permit), effective on December 28, 2012. The permit requires that the Los Angeles County Flood Control District (LACFCD), the County of Los Angeles, and 84 of the 88 cities (excluding Avalon, Long Beach, Palmdale, and Lancaster) within Los Angeles County comply with the prescribed elements of the MS4 Permit.


The MS4 Permit identifies the City of Hermosa Beach as a permittee that is responsible for compliance with the MS4 Permit requirements and on December 26, 2013 the city entered into a Memorandum of Understanding (MOU) with the cities of Manhattan Beach, Redondo Beach and Torrance, and Los Angeles County to collaborate in the development of a Draft and Final Enhanced Watershed Management Program (Beach Cities EWMP) and a Draft and Final Coordinated Integrated Monitoring Program (CIMP).


The final Beach Cities EWMP was submitted and approved by the Executive Officer of the Regional Board via letter dated April 18, 2016 (EWMP Approval Letter) and the final CIMP was approved on November 12, 2015. The EWMP Approval Letter directs the Beach Cities WMG to begin implementing the EWMP immediately and compliance will be determined based on compliance actions, milestones and schedules included in the EWMP and listed in the EWMP Approval Letter.


The Beach Cities EWMP identifies regional structural watershed control measures (Regional Structural Projects) that when implemented together with specified distributed structural control measures (Distributed Structural Projects) and nonstructural measures described below, are designed to achieve compliance with interim and final water quality goals. Recommended Regional and Distributed Structural Projects located in Hermosa Beach include: 1) Hermosa Beach Infiltration Trench, 2) Hermosa Beach Greenbelt Infiltration, and 3) Distributed Green Streets.


Furthermore, implementing nonstructural (e.g., programmatic) BMPs that target the pollutants identified in the EWMP are prioritized over structural BMPs due to their lower relative cost. Examples include new or enhanced pet waste controls (ordinance, signage, etc.), Clean Bay Restaurant Program, enhanced street sweeping, increased catch basin and storm drain cleaning and incentivizing the public to decrease the amount of stormwater runoff from their property, via downspout disconnection programs and rain barrels.


Additionally, beginning in 2001, redevelopment projects were required by the Permit (via the Standard Urban Stormwater Management Program [SUSMP]) to incorporate stormwater treatment BMPs into their projects if their project size exceeded specified thresholds. The 2001 MS4 Permit SUSMP redevelopment requirements were applied between 2003 and 2015 for the SMB EWMP area. The 2012 MS4 Permit established new criteria for redevelopment projects, requiring certain sized projects to capture, retain, or infiltrate the 85th percentile design storm or the 0.75-inch design storm, whichever is greater, via the implementation of LID BMPs. The Green Streets Policy and LID ordinance adopted by City Council on May 26, 2015 established this criteria for permit compliance.


This study session provides an update on the City’s progress in complying with the 2012 MS4 permit requirements by implementing the actions described in the Beach Cities EWMP.



The EWMP includes both existing and proposed regional and distributed structural BMPs to address water quality targets in the SMB Watershed. Because bacteria were identified as the controlling pollutant of concern, infiltration BMPs were prioritized as they are most effective for addressing bacteria. Table 1 shows the proposed Structural BMPs and the implementation schedule. A description of each proposed project located in Hermosa Beach is provided below.


Table 1. Proposed Project Sequencing in the Santa Monica Bay Watershed