Final Notice and Public Explanation of a Proposed Activity in a 100-Year Floodplain

To: All interested Agencies, Groups, and Individuals

This is to give notice that the County of San Mateo has determined that the following proposed action by MidPen Housing Corporation (MidPen) to be funded under the Project-Based Voucher (PBV) Program is located in the 100-year floodplain and the County of San Mateo will be identifying and evaluating practicable alternatives to locating the action in the floodplain and potential impacts on the floodplain from the proposed action, as required by Executive Order 11988, in accordance with HUD regulations at 24 CFR 55.20 Subpart C Procedures for Making Determinations on Floodplain Management and Protection of Wetlands. The proposed project is located at 1580 Maple Street, Redwood City in San Mateo County. The project is the new construction of 110 units of permanent supportive affordable housing on an approximately 1.5-acre parcel. The project will apply for HUD Project-Based Vouchers.

The County of San Mateo has considered the following alternatives and mitigation measures to be taken to minimize adverse impacts and to restore and preserve natural and beneficial values: Four alternatives were considered: 1) Alternative 1 – abandoning this project site and building the project on another site in the City of Redwood City that is not in a floodplain, if one of adequate size can be located; 2) Alternative 2 – abandoning this project and project site and proposing the same or similar project at another site that is outside the City that is not in a floodplain; 3) Alternative 3 - Build project in the current location in the floodplain but build a levee/seawall to protect the site, and; 4) Alternative 4 - the No-Action Alternative - abandoning the project entirely and not proceeding with construction of the project at any location.

Alternative 1 was determined to not be a practicable alternative due to there being no undeveloped sites in Redwood City with the size, zoning, availability, and financial feasibility necessary for development of the project. Alternative 2 was determined to not be a practicable alternative because abandoning this project site and seeking another site elsewhere outside Redwood City that is not in a floodplain fails to address the significant need for quality permanent supportive housing within the City of Redwood City. Further, even if such a site could be found, the cost of purchasing an undeveloped, adequately sized, and appropriately zoned site from a private seller would make the project infeasible. Alternative 3 was determined to not be a practicable alternative because building the project in the current location in the floodplain but with a levee/seawall to protect the site would be infeasible as it would divide our development from the neighboring 1548 Maple townhomes development. The City of Redwood City has decided to raise the surrounding areas and have already made the determination that doing so would not impact the community. Adding a levee would not be consistent with the mitigation methods of the surrounding sites. Alternative 4 - the No-Action Alternative, was determined to not be a viable or practicable alternative as it would leave Redwood City with a significant and overriding need for quality affordable housing.

The County of San Mateo has reevaluated the alternatives to building on a site located in a 100-year floodplain and has determined that it has no practicable alternative. Files that document compliance with Steps 3 through 6 of Executive Order 11988 are available for public inspection, review and copying upon request at the times and location delineated in the last paragraph of this notice for receipt of comments.

A Conditional Letter of Map Revision based on Fill (CLOMR-F) is to be submitted to FEMA to confirm the property, once elevated, will be above the 100-year base flood elevation (BFE) of 10 feet, NAVD 88. The area to be removed will be provided as a metes and bounds description to be submitted with the CLOMR-F. The lowest lot elevation within the metes and bounds area will be elevated a minimum of two feet above the BFE.  FEMA will review the application and provide a determination regarding the flood hazard zone. If FEMA finds the metes and bounds area is proposed to be sufficiently elevated, we expect the area to be conditionally designated as Zone X. If the CLOMR-F process continues to be suspended by FEMA, the project will proceed with elevating the site by fill above the 100-year base flood elevation and will purchase flood insurance. MidPen would obtain flood insurance protection against potential loss due to damage from flooding as required under the National Flood Insurance Program and otherwise comply with the regulations of the Federal Emergency Management Agency (FEMA) found in 44 CFR Part 59-77; said insurance would remain in effect until the site is removed from the floodplain.

The project as proposed includes additional standard mitigation measures to manage stormwater and prevent erosion. Measures include bioretention areas, the use of native trees, shrubs and groundcover plantings and shrubs in planting and implementing a stormwater pollution prevention plan during construction. The project as proposed also included features that reflect its beneficial values of providing high quality permanent housing for the unhoused; such features are on-site art therapy and community programming space, community garden beds, a dog relief area, and a landscaped courtyard for outdoor gatherings and relaxation.

There are three primary purposes for this notice. First, people who may be affected by activities in floodplains and those who have an interest in the protection of the natural environment should be given an opportunity to express their concerns and provide information about these areas. Second, an adequate public notice program can be an important public educational tool. The dissemination of information and request for public comment about floodplains can facilitate and enhance Federal efforts to reduce the risks and impacts associated with the occupancy and modification of these special areas. Third, as a matter of fairness, when the Federal government determines it will participate in actions taking place in floodplains, it must inform those who may be put at greater or continued risk.

Written comments must be received by the County of San Mateo at the following address on or before November 2, 2023: San Mateo County, Department of Housing, 264 Harbor Blvd., Building A, Belmont, CA 94002, Attention: Raymond Hodges, Director. A full description of the project may be reviewed from 9:00 AM to 5:00 PM at the address above. Comments may also be submitted via email at

Date: October 26, 2023