DR-4683-CA Final Public Notice

FINAL PUBLIC NOTICE: Stanford Health Care Redwood City Outpatient Center Flood Hazard Mitigation Project, San Mateo County, CA | HMGP-4683-1122-063

The U.S. Department of Homeland Security’s Federal Emergency Management Agency (FEMA) proposes to provide federal financial assistance under the Hazard Mitigation Grant Program to the Stanford Health Care in San Mateo County, California, to mitigate flood hazards by modifying and upgrading minor elements within the facility. Pursuant to Executive Order 11988 (Floodplain Management), Executive Order 11990 (Wetlands Management), and FEMA’s implementing regulations at Title 44 of the Code of Federal Regulations Part 9, FEMA hereby provides interested parties with a notice of its final decision and an explanation of the alternatives that were considered.

The purpose of the proposed action is to reduce the risk of flood damage to Stanford Health Care Outpatient Center in Redwood City, California (37.485283, -122.202408). The proposed action consists of the following components: 1) increasing the existing sump pump capacity, 2) fitting the pumps with check valves, 3) replacing the existing drain lines, 4) installing flood gates by the parking ramps, 5) raising the height of the existing retaining walls along parking ramps, 6) raising the top elevation of the lower-level stairs and associated stem walls to reach above flood elevation, 7) installation of handrails, and 8) replacement of landscaping such as shrubs and ornamental grass. Ground disturbance would only occur within pre-disturbed areas where existing infrastructure is present. No in-water work, water diversion, or removal of riparian vegetation would occur. Trenching, within the parcel boundaries, would be required to replace the existing drain lines, and is limited to previously disturbed soils. 

The project area is partially located in the 100-year floodplain as depicted on the FEMA Flood Insurance Rate Map (FIRM) Number 06081C0302F, effective date April 5, 2019. The FIRM shows that the project area partially lies within Zone AE, an area that has a 1 percent annual chance flood and where a base flood elevation has been established and is in a regulatory floodway. The majority of the project area is located within a 500-year floodplain, an area with 0.2% annual chance flood hazard, depicted by a shaded Zone X. The U.S. Fish and Wildlife Service National Wetlands Inventory map shows the project is not in or adjacent to wetlands. 

A map of the project area and its location within the floodplain is available for public inspection. Parties interested in receiving a copy of the map should contact the FEMA Region 9 Environmental Officer using contact information provided in this notice. 

Two alternatives to the proposed action were considered: Alternative 1, No Action; Alternative 2: Addition of floor drains with associated sumps. Alternative 1 would not protect the critical facility against future flooding. This Alternative is not recommended because the risk of flood damage would remain. Alternative 2 included adding floor drains with associated sumps and sump pumps. This Alternative is not recommended as it focuses on addressing the consequences of flooding rather than preventing future flooding. While pumping out floodwater can help manage water levels and mitigate damage, it doesn't eliminate the risks associated with flooding. One of the critical factors that influenced the decision against the floor drains and sump pumps approach was the facility's mat-slab foundation design. While this type of foundation is advantageous for structural stability, it can present challenges when trying to cut into the concrete to install stumps and drain lines. The complexity of cutting into the mat-slab foundation would not only make the process laborious and time-consuming but also significantly increase the cost of implementing such a system. The potential disruption to the existing structure during the installation process could also pose risks to the facility's overall integrity. FEMA has determined that the proposed project is the only practicable alternative available; therefore, the proposed action must be located in the floodplain. The proposed action would have no significant adverse impact on the floodplain and would reduce the risk of flooding and flood damage on the critical facility. Stanford Health Care has declared that the proposed action conforms to local floodplain standards, and would be responsible for the management, construction, and maintenance of the proposed action. 

The proposed action would have no permanent adverse impact on wetlands. Work would occur within the footprint of existing infrastructure. No riparian vegetation would be removed. The area is mulched and irrigated with shrubs and ornamental grasses. 

Additional information about FEMA’s proposed action may be requested by writing the FEMA Region 9 Environmental Officer at FEMA, 1111 Broadway, Suite 1200, Oakland, California 94607, or fema-rix-ehp-documents@fema.dhs.gov.  All requests should be received no later than 15 days after publication of this notice. No action will be taken before this date.