1 TO: City Council
FROM: Andrew Vialpando, City Manager
PREPARED BY: Lina Hernandez, Deputy City Manager/Public Works Director MEETING DATE: December 17, 2024
SUBJECT: First Amendment to the Agreement with Hazen and Sawyer for Design Services for the Downtown Lomita Multi-Benefit Stormwater Project
RECOMMENDATION
Approve the First Amendment to Agreement 2023-49 with Hazen and Sawyer for Design Services for the Downtown Lomita Multi-Benefit Stormwater Project; approve Change Order No. 1; appropriate an additional $215,740 plus a 10% contingency of $21,574 for unexpected costs in a total amount not to exceed $237,314 from Measure W Municipal Fund; and authorize the City Manager to execute the Amendment.
BACKGROUND
The Engineering Design Services provided by Hazen and Sawyer for the Downtown Lomita Multi-Benefit Stormwater Project includes the design of stormwater features along Lomita Boulevard and Narbonne Avenue to mitigate local and downstream flood risk, improve water quality, and reduce the heat island effect in the downtown Lomita area. In addition, the project includes features to beautify the neighborhood and promote healthy transportation and recreation. The Project is intended to divert 5.6 acre-feet of stormwater from Los Angeles County Flood Control District (LACFCD) storm drains in the downtown area of Lomita to stormwater control features in the area. Additional proposed features include bioretention areas, pervious pavement, planting of vegetation with droughttolerant native plants, 45 new shade trees, 10 benches, bike locking stations, educational signage, and a bike lane along a section of Lomita Boulevard.
The City Council approved the award of this design contract to Hazen and Sawyer on December 19, 2023. Hazen and Sawyer was given the Notice to Proceed with the work on January 9, 2024.
CITY OF LOMITA
CITY COUNCIL REPORT
Item No.
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2 DISCUSSION
The initial design included an infiltration gallery on Narbonne Avenue and a series of dry wells along Lomita Boulevard. The initial stages of the design revealed two significant challenges.
Initially, research revealed that a gas station had previously occupied the site of the proposed location for the infiltration gallery. While the site had been remediated for previous underground storage tank leakage, it was determined that the site would not be suitable for a project that would infiltrate significant quantities of water into the soil at this site.
A subsequent geotechnical study revealed lower-than-expected infiltration rates in all locations. As a result, the number of dry wells necessary to infiltrate the same amount of stormwater was too large to be feasible. Therefore, it was determined that one larger infiltration gallery, rather than a small infiltration gallery and a series of dry wells, would be the best option.
The City and Hazen and Sawyer researched many options for potential sites for an infiltration gallery including City-owned properties, private properties, public-private partnerships, and a partnership with LAUSD. Most options were rejected because of excessive cost for piping to reach long distances to parks, the need to install pipes at great depths due to other underground utilities, and the need to purchase property, or because of the acceptance of excessive liability if partnering with other entities. This lengthy process resulted in two releases of contingency amounts totaling $24,000.
It was determined that the ideal property would be City-owned, near the intersection of Narbonne Avenue and Lomita Boulevard, and large enough to hold the infiltration gallery.
The City Hall front lawn and rear parking lot have been identified as ideal locations for the infiltration gallery.
A geotechnical investigation, hydraulic modeling, and design modifications will need to be performed for the newly proposed locations. Change Order No. 1 and the previously released contingencies of $24,000 are for the additional investigations and analyses necessary due to the discoveries described above.
FISCAL IMPACT
Staff is recommending authorizing an additional appropriation in the amount of $215,740 plus a 10% contingency of $21,574 for unexpected costs for a total additional not to exceed amount of $237,314 from the Measure W Municipal Fund. City Council approved an appropriation of $939,155 on December 19, 2023. This current request is in addition to the previously appropriated amount. The City has sufficient funds in its Measure W 3 Municipal Fund to cover these additional costs.
Based on the change order fee amount, sufficient funds are available to fund the additional design costs of the project.
OPTIONS
1. Approve Staff’s recommendations.
2. Provide staff with further direction.
ATTACHMENTS
1. First Amendment to Agreement 2023-49 with Exhibit A (Change Order)
2. Agreement 2023-49 with Hazen and Sawyer
Reviewed by: Approved by:
_______________________ ______________________
Gary Y. Sugano Andrew Vialpando
Assistant City Manager City Manager
Prepared by:
__________________________
Lina Hernandez
Deputy City Manager/Public Works Director