TO:
Honorable Mayor and Members of the City Council
THROUGH:
Talyn Mirzakhanian, City Manager
FROM:
Erick Lee, Public Works Director
Katherine Doherty, City Engineer
Jeff Fijalka, Principal Civil Engineer
Erik Zandvliet, City Traffic Engineer
SUBJECT:Title
Consideration of a Resolution Approving the Final Construction Drawings and Specifications for the 28th Street Stormwater Infiltration Project and Authorizing Solicitation of Competitive Bids for Construction of the Project; and Consideration of a Resolution Authorizing a Use and Maintenance Agreement with the County of Los Angeles Regarding a Connection to the County-Owned Storm Drain at 28th Street (No Budget Impact) (Public Works Director Lee).
(Estimated Time: 1 Hr.)
ADOPT RESOLUTION NOS. 25-0029 AND 25-0030
Body
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RECOMMENDATION:
Staff recommends that the City Council:
A. Adopt Resolution No. 25-0029, approving the final construction drawings and specifications for the 28th Street Stormwater Infiltration Project and authorizing the solicitation of competitive bids for the construction of the Project; and
B. Adopt Resolution No. 25-0030, authorizing a Use and Maintenance Agreement with the County of Los Angeles regarding a connection to the county-owned storm drain at 28th Street.
FISCAL IMPLICATIONS:
There are no direct fiscal implications associated with this item. The City has secured grant funding sufficient to cover all project design and construction costs. The City has been awarded over $30M in grant funding from three separate agencies to design and construct the stormwater infiltration system. Refer to the attached Budget and Expenditures Summary Report for additional details.
BACKGROUND:
Stormwater discharges from within the City of Manhattan Beach are governed by a Municipal Separate Storm Sewer System (MS4) Permit issued by the Los Angeles Regional Water Quality Control Board (Water Board). The MS4 permit was created to enforce State and Federal water protection measures. Per the terms of the permit, the City is responsible to sample stormwater discharges into Santa Monica Bay, test them for specified contaminants (namely bacteria), and report findings to the State.
Twenty years of monitoring data have consistently shown a relationship between stormwater discharges from the 28th Street drain and bacterial exceedances in water samples collected at the outfall of this drain. Stormwater quality regulations established by the Water Board allow the bacteria count in water samples to exceed a pre-defined limit, or Total Maximum Daily Load (TMDL), a maximum of seventeen days per wet weather season. Samples collected at the outfall of the 28th Street drain have exceeded the TMDL on more than seventeen days for ten of the last twenty years, indicating that the City is out of compliance with ocean protection regulations. However, the compliance deadline for bacterial discharges into Santa Monica Bay was July 15, 2024, so exceedances prior to this date are not subject to penalties.
In accordance with the requirements of the 2012 updates to the MS4 permit, the cities of Manhattan Beach, Hermosa Beach, Redondo Beach, and Torrance, and the Los Angeles County Flood Control District (LACFCD) jointly developed an Enhanced Watershed Management Program (the Beach Cities EWMP, now shortened to WMP). The original Beach Cities WMP identified potential capital improvement projects capable of minimizing wet weather discharges and eliminating dry weather discharges into Santa Monica Bay, with the goal of reducing pollutants entering the Bay and meeting the water quality-based outflow limitations.
The proposed 28th Street Stormwater Infiltration Project (the Project) is identified within the Beach Cities WMP as the highest priority proposed project capable of significantly reducing bacterial, trash, and debris discharges into South Santa Monica Bay. This is largely due to the size of the drainage area contributing to the 28th Street storm drain. Approximately 60 percent of the stormwater that falls in Manhattan Beach is collected by the 28th Street drain and is discharged directly to the ocean through this single pipe.
In April 2020, the City contracted with CWE, a civil engineering firm specializing in water resources, to perform a feasibility study to identify potential locations to construct a stormwater infiltration system capable of capturing flows from the storm drain system that collect in the 28th Street drain. The investigation performed by CWE assessed the suitability of three separate sites for the infiltration system, including Polliwog Park, the 26th Street Parking Facility (the 26th Street lot), and the beach along the west side of the Marvin Braude Bike Trail between 26th and 27th Streets. Site soils at Polliwog Park were found to be less favorable for infiltration, and the 26th Street lot was ultimately recommended as the preferred project site.
At the conclusion of the feasibility study, staff submitted applications for grant funding to help cover the cost of constructing the Project. The City was ultimately awarded $17,620,030 from the Los Angeles County Safe, Clean Water Program, $4,936,566 of Proposition 68 funding administered by the California Natural Resource Agency, and $8,535,000 of Proposition 1 funding administered by the California Water Boards.
In March 2022, the City awarded a contract to CWE to design a stormwater infiltration system to be constructed at the 26th Street lot, as recommended in the feasibility study. At the sixty percent design level, construction drawings were presented to the Los Angeles County Beaches and Harbors Commission for conceptual approval of the Project. The Project received conceptual approval during that meeting, and the City subsequently entered into a Memorandum of Understanding with Los Angeles County, authorizing the City to construct stormwater distribution and infiltration features and other site improvements within the county-owned 26th Street lot.
The professional services agreement with CWE also included a study to assess potential environmental impacts of the Project, both temporary and permanent. The results of that study are summarized in an Informational Study/Mitigated Negative Declaration (IS/MND). Per the IS/MND, potential environmental impacts associated with the Project can be mitigated through implementation of the measures identified within the document. Specific mitigations that are required to lessen environmental impacts during construction are described in a separate Mitigation Monitoring and Reporting Plan (MMRP). Both documents were presented during the May 21, 2024 Regular City Council Meeting. During that meeting City Council voted to adopt a Mitigated Negative Declaration California Environmental Quality Act (CEQA) determination and also approved a Coastal Development Permit for the Project, to ensure that the constructed improvements comply with the development standards set forth in the City’s Local Coastal Program.
Refer to the attached List of Previous City Council Actions for a summary of all past City Council actions relating to the Project.
DISCUSSION:
System Configuration
To reduce or eliminate the pollutant exceedances from the 28th Street drain, the Project will intercept this pipe at Manhattan Avenue and will divert storm flows to an underground pump station below Manhattan Avenue. Stormwater will be pumped into a trash removal device and will then route through a series of sedimentation chambers before being distributed to a matrix of drywells located in the 26th Street lot and at Bruce’s Beach Park, as shown in the attached construction drawings.
Construction of the diversion structure will require the excavation of a pit within the intersection of 28th Street and Manhattan Avenue at the location of the 28th Street drain. The excavated pit will be on the order of 50 feet deep. A diversion pipe will extend to the south from the diversion structure to the pump station below Manhattan Avenue between Bruce’s Beach Park and the 26th Street lot. This pipe will be bored into place horizontally to avoid an open excavation along the full length of the 2700 block of Manhattan Avenue.
Below the segment of Manhattan Avenue between Bruce’s Beach Park and the 26th Street lot, a series of buried concrete structures will be installed to house pump equipment, a trash capture system, and a series of sedimentation chambers. Stormwater leaving the sedimentation chambers will be diverted to an array of forty drywells, eight of which will be drilled below Bruce’s Beach Park. The remaining 32 drywells will be within the 26th Street lot.
Prior to installation of the drywells at the 26th Street lot, the existing deteriorated perimeter retaining walls will be demolished and reconstructed. After the completion of drywell construction, a new pervious concrete surface will be placed throughout the parking lot. New striping will reverse the direction of traffic flow on the upper parking tier for improved traffic circulation, and ADA-complaint parking spaces will be incorporated into the parking layout for increased accessibility. The existing staircases from the upper parking tier to the lower tier, and from the lower tier to Ocean Drive, will both be eliminated. Accessible pedestrian routes will be constructed from each parking tier to the abutting sidewalks along 26th Street and 27th Streets.
Use and Maintenance Agreement
As a condition of issuing a permit to connect to the existing county-owned storm drain at 28th Street, Los Angeles County is requiring that the City enter into a Use and Maintenance Agreement with the County to regulate the construction activities and define the maintenance responsibilities associated with the connection. A copy of the agreement is attached for review.
Construction Sequencing and Timeline
Construction of the Project is anticipated to take approximately sixteen to eighteen months to complete. A breakdown of the planned construction sequence is provided in the Construction Schedule. After a construction contract is awarded, the Contractor may propose modifications to the construction timeline that reduce durations or mitigate impacts to the surrounding community. However, per County regulations, the connection to the County storm drain at 28th Street must occur during the dry season, which is stipulated as April 15th through October 15th of each year.
Traffic and Parking Impacts
Due to the extensive reconstruction work that will be performed in and around the 26th Street lot, the parking lot will be closed to the public for a period of approximately 12 to 15 months. The lot will remain in operation through the 2025 summer season and will close after Labor Day 2025 to allow construction activities to commence within the lot.
Residents who currently hold overnight parking permits for this facility will be offered overnight permits within the El Porto Parking Lot or the Pier Parking Lots. Additionally, staff is currently working with the Manhattan Beach Unified School District to offer displaced overnight permit holders passes to park within the Grand View Elementary Parking Lot.
In addition to the parking lot closure, the segment of Manhattan Avenue between 26th Street and 27th Street will be closed to vehicular and pedestrian traffic for approximately six to nine months to allow for construction of the pump station, sedimentation system, and associated piping. This closure will not prevent access to the Los Angeles County Lifeguard Training Center or any residential parcels. Electronic message boards will be placed on Manhattan Avenue and Highland Avenue in advance to inform commuters of this closure. During the closure, vehicles traveling northbound on Manhattan Avenue between Marine Avenue and 26th Street will be diverted to Ocean Drive, which will be temporarily restricted to northbound travel only between 26th Street and 27th Street. Vehicles traveling southbound on Manhattan Avenue from north of Bruce’s Beach will be diverted to Highland Avenue to avoid the closure.
To help offset the loss of seven parking spaces along northbound Manhattan Avenue during the closure, the existing street parking along the 200 block of 27th Street will be shifted from the north side of the street to the south side, allowing for a net gain of four parking spaces along this street segment. Additionally, the centerline on Manhattan Avenue between 27th Street and 28th Street will be shifted to the east, adding another five street spaces, for an overall gain of two street spaces during construction. Construction within the parking lot will result in the temporary removal of 67 spaces.
A roadway closure will also be implemented at the intersection of Manhattan Avenue and 28th Street. This closure is expected to last approximately six to eight months, to allow for the construction of the diversion structure and the installation of bored piping that will extend from the south side of the structure to the pump station. This closure will prevent vehicular traffic in all directions from passing through the intersection of 28th Street and Manhattan Avenue and will restrict vehicular access to the garage at 2720 Manhattan Avenue. For the duration of this closure, southbound traffic along Manhattan Avenue will be diverted to Highland via 33rd Street.
Lastly, lane closures around the perimeter of the 26th Street lot will occasionally be required to accommodate the replacement of perimeter retaining walls and installation of distribution piping. These closures will likely last one to three weeks, and when feasible, traffic lanes will be re-opened to traffic during non-working times.
Project Alternatives
If approved by City Council, the Project will move forward to the bidding phase and then into construction. Based on the Engineer’s cost estimate, staff anticipates that all construction activities will be covered by the grant funding previously awarded to the City. Per the proposed construction schedule, all construction activities will be complete prior to the 2026-2027 wet season, and the City will achieve compliance with bacteria and trash TMDL requirements as specified in the WMP document.
Alternatively, any significant delays or modifications to the Project will jeopardize grant funding and render the City unable to comply with Water Board regulations as planned, which could subject the City to regulatory agency penalties and may expose the City to third-party lawsuits.
Should City Council opt to abandon the current system design, staff would work with the City’s stormwater consultants to identify multiple alternative projects that collectively address trash and bacterial discharges from the 28th Street storm drain. These distributed projects would likely take decades to design and construct and total construction costs could be orders of magnitude greater than the current cost of the 28th Street Stormwater Infiltration Project. Additionally, the City has spent over $1.2 million to design the current Project. If the Project is abandoned, this action could be considered a violation of grant agreements. As a result, the granting agencies that have funded these expenditures could require the City refund grant monies already received. Furthermore, any pending grant reimbursement requests for the current Project could be denied.
PUBLIC OUTREACH:
Community meetings were held in the fall of 2020 during the development of the project feasibility study.
On July 26, 2023, Public Works staff presented the project concept to the Los Angeles County Beach Commission. A similar presentation was provided to the Manhattan Beach Parking and Public Improvement Commission (PPIC) on October 26, 2023. Both public meetings were noticed as required by State law. Additionally, post cards were mailed to residents in the vicinity of the Project to inform them of the PPIC meeting, and the meeting was included on the events calendar on the City’s webpage.
During the project design phase, an onsite event to discuss the Project with interested community members was held on October 10, 2023, and an additional community meeting was held at the Manhattan Heights Community Center on February 15, 2024. Both events were announced during City Council meetings, on social media platforms, on the City’s website, and through direct mailings to nearby residents.
Pursuant to CEQA, the Draft IS/MND was circulated for a 31-day public review from February 16, 2024 through March 18, 2024. A Notice of Intent to Adopt (NOI) the MND was mailed to owners and occupants within 100 feet of the project site, published in The Beach Reporter, advertised on the City’s social media platforms, and posted on signs within and around the project site. Additionally, the NOI was filed with the County Clerk and the State Clearinghouse and mailed to responsible agencies. The Draft IS/MND was posted on the City’s website, and paper copies were made available for review at City Hall, the Manhattan Beach branch of the Los Angeles County public library, the Joslyn Community Center, and Manhattan Heights Community Center.
A public notice for the May 21, 2024 public hearing was published in The Beach Reporter, mailed to all property owners and residents within 100-foot radius of the project site, and posted at City Hall and on the City’s website.
On February 6, 2025, Public Works staff held a community meeting at Manhattan Heights to provide an additional opportunity for the public to learn about the Project and the associated construction impacts. Over one thousand postcards were mailed to residents to inform them of the meeting, in addition to onsite signage, social media posts, and notifications on the City’s website and within newsletters prepared and distributed by the City.
Additionally, the City maintains a dedicated project webpage (<https://www.manhattanbeach.gov/departments/public-works/engineering-division/subsurface-infiltration-drainage-project>) to provide periodic updates to the public.
ENVIRONMENTAL REVIEW:
The City has reviewed the project for compliance with the California Environmental Quality Act and has determined that the proposed project was adequately addressed in the previously adopted Mitigated Negative Declaration (MND) prepared for the project. The City Council adopted the MND on May 21, 2024, through Resolution No. 24-0043. There are no substantive changes proposed and no substantive changes in the circumstances under which the proposed project will be undertaken that affect the analysis previously conducted. Thus, no further environmental review or documentation is necessary.
LEGAL REVIEW:
The City Attorney has reviewed this report and determined that no additional legal analysis is necessary.
ATTACHMENTS:
1. Resolution No. 25-0029
2. Resolution No. 25-0030
3. Budget and Expenditures Summary Report
4. 2021 Feasibility Study
5. List of Previous City Council Actions Related to the Project
6. Construction Drawings
7. Construction Specifications
8. Use and Maintenance Agreement with Los Angeles County for Storm Drain Connection
9. Preliminary Construction Schedule
10. Proposed Traffic Flow and Parking Modifications
11. Resident Notification for March 18, 2025 City Council Agenda Item
12. Location Map
13. PowerPoint Presentation