Title
Staff Report for a City of San Leandro City Council Resolution to Approve a Cooperative Agreement with Alameda County Flood Control and Water Conservation District for Improvements to the Estudillo Canal and the Monarch Bay Drive Bridge
Staffreport
SUMMARY AND RECOMMENDATIONS
This action approves a Cooperative Agreement with the Alameda County Flood Control and Water Conservation District that provides for improvements to the Estudillo Canal to improve flood protection and improvements to the Monarch Bay Drive Bridge to repair erosion.
Staff recommends:
• Approval of an agreement with the Alameda County Flood Control and Water Conservation District (District) for Improvements to the Estudillo Canal and the Monarch Bay Drive Bridge.
• Authorization to pay up to $350,000 to the District for construction work and construction management on the Monarch Bay Drive Bridge, as described in the Cooperative Agreement.
BACKGROUND
Estudillo Canal is an engineered channel that begins just west of I-580 near Fairmont Drive, where it receives drainage from the ridge above the Fairmont Hospital and the surrounding area. The canal flows south crossing East 14th Street and around the southern portion of Bayfair Shopping Center, then turns west and flows to San Francisco Bay, capturing storm water from as far north as Williams Street and as far south as Lewelling Boulevard. Constructed in 1958 by the District, the canal greatly reduced the risk of flooding in the Washington Manor, Floresta Gardens, Marina Faire, and Mulford Gardens neighborhoods.
The National Flood Insurance Act of 1968 and the Flood Disaster Protection Act of 1973 led to the creation of flood insurance rate maps (‘flood maps’ or FIRM) which classify the risk of flooding for each parcel of land. The flood maps have been updated many times since 1973 and the most recent update, in December 2018, indicates that when there is both high tide and high storm water runoff at the same time, there is a 1% risk of flooding for portions of the Marina Faire and Mulford Gardens neighborhoods.
The District has designed modifications to the canal to prevent water from overtopping the north bank of the canal and reducing the risk of flooding for these neighborhoods by storing storm water during high flow and high tide conditions in the City’s dredge materials management site (DMMS) immediately adjacent and south of the canal. Additionally the District plans to reconstruct the exiting deteriorating tide gate structure approximately 465 feet east of Monarch Bay Drive Bridge.
In 1977 the City built the Neptune Drive Bridge over the Estudillo Canal, the name of the road and bridge were later changed to the Monarch Bay Drive. The bridge carries the Bay Trail for bicycles and pedestrians and is used by service vehicles to maintain the trail, the marshland south of the Estudillo Canal, and a treated effluent pumping station. The bridge also serves as a secondary exit for the Heron Bay neighborhood should the primary neighborhood exit to Lewelling Boulevard be blocked for a significant amount of time. The southern abutment of the Monarch Bay Drive Bridge has experienced erosion due to storm surges and daily tidal flows and is in need of maintenance work. The northern abutment received maintenance work in 2014 and is in good condition.
The work on the Estudillo Canal and the Monarch Bay Drive bridge are of similar character, requires permits from the same agencies, and contractors that are interested in one project are likely interested in both. These characteristics highlighted the opportunity for efficiency by completing the projects together. As such, the District prepared and submitted environmental regulatory permit applications for the combined project and has secured the necessary permits prior to beginning of construction.
Analysis
To improve the flood control capabilities of the Estudillo Canal west of Wicks Boulevard, the District, after completing a hydraulic study, requested permission to occasionally divert storm water in to the City’s DMMS during major storm events. The temporarily diverted storm water flow would then drain back into the Estudillo Canal within approximately 48 hours. Granting this permission will require that the City maintain the DMMS in a condition suitable for accepting the storm water and will allow the District to construct improvements, which will reduce the risk of flooding from the Estudillo Canal for approximately 1,100 parcels of land within San Leandro.
It is uncertain whether or not the canal could be designed to prevent overtopping and not use the DMMS for temporary storage, but it is certain that if it is possible to prevent overtopping the project would be considerably more expensive. The District will need an easement to allow maintenance for a portion of the proposed improvements that encroach upon the City owned DMMS. This easement will be completed within six (6) months of executing the proposed Agreement.
The District project will remove one source of flooding for the parcels in the Marina Faire and Mulford Gardens neighborhoods, but those parcels will not see a reduction in flood risk until another project is also constructed. The Neptune Drive Shoreline Flood Protection project is a City project to construct a levee and wall adjacent to the Bay near the intersection of Neptune Drive and Marina Boulevard that will complement the District project on the Estudillo Canal such that the 1,100 parcels mentioned above will have a reduced risk of flooding when both projects are constructed.
The City intends to ask the impacted properties to vote on an assessment district to fund the Neptune Drive work in late 2020 and if approved, will have the work completed at the same time as the District project on Estudillo Canal is completed. FEMA will need to certify the work before the maps are modified to show reduced risk of flooding for the properties.
The City prepared plans for the maintenance of the southern abutment of the Monarch Bay Drive Bridge and after identifying the mutual benefits such as shared tidal control during construction, the District offered to include these plans as a bid alternate to their plans for the Estudillo Canal. If the alternate bid is accepted by the City, the work will be constructed by one contractor. The proposed agreement states that the District will pay the contractor for the work and the City will pay the District for the cost of the construction plus administration of the contract. Alternatively, the City could bid and manage the bridge work separate from the District project. The cost of doing the work separately is estimated to be higher than the cost for the District to include the work in its project. Additionally, the City’s project managers are fully engaged on other projects and if this work were not done by the District, it would potentially be delayed.
Current Agency Policies
• Maintain and enhance San Leandro’s infrastructure.
Applicable General Plan Policies
• Policy EH-1.7 Reducing Flood Hazards: Work collaboratively with County, State, and federal agencies to develop short and long-term programs that reduce flood hazards in the City.
• Policy CSF-6.8 Maintenance: Ensure that sufficient funding is provided for the ongoing maintenance of City-owned facilities, including streets, street lights, traffic signals, landscaping, street trees, storm drains, public buildings and other infrastructure.
Permits and/or Variances Granted
Permits for the work have been granted by the Army Corps of Engineers, California State Water Resources Control Board, San Francisco Bay Conservation and Development Commission, U. S. Fish and Wildlife Service and the California Department of Fish and Wildlife.
Environmental Review
The District found the canal project to be categorically exempt from the California Environmental Quality Act.
The bridge work is categorically exempt per CEQA Section(s) 15302(c) Replacement or Reconstruction of existing facilities with no expansion of capacity.
Summary of Public Outreach Efforts
The modifications to Estudillo Canal were included in discussions with the public about the Neptune Drive Flood Protection project. Public meetings were held on July 29, 2019 and November 13, 2019.
Monarch Bay Drive Bridge will remain open to bicycles and pedestrians throughout the project; signs will be posted alerting users to the construction.
Fiscal Impacts
There is no fiscal impact to the City for the work on the Estudillo Canal.
The total cost of the Monarch Bay Drive Bridge project is as follows:
Design and Bid: $25,000
Construction Contract: $250,000
District cost for construction administration: $37,500
Contingency: $62,500
City Inspection: $15,000
Total $390,000
Budget Authority
The bridge project is funded as follows:
Account No. Reso., Appropriation Dates & Source Amount
141-38-394 CIP budget FY 17-18 $550,000
Attachment to Related Legislative File
• Cooperative Agreement - Alameda County Flood Control and Water Conservation District
PREPARED BY: Nick Thom, City Engineer, Engineering and Transportation Department