Division IV: Overlays and Plan Districts
Public Review Draft | South San Francisco Zoning Code | Division IV, Page 1 Chapter 20.140 Planned Development (PD) District
No changes are recommended to this chapter.
Chapter 20.150 Reserved
Loft (L) Overlay district to be deleted.
Chapter 20.160 Reserved
Hillside (HS) Overlay district to be deleted.
Chapter 20.170 Special Environmental Studies (ES) Overlay District
No changes are recommended to this chapter.
Chapter 20.180 Flood Plain/Sea Level Rise (SLR) Overlay
20.180.001 Purpose
The Flood Plain/Sea Level Rise (SLR) Overlay District is intended to protect areas projected to be impacted by sea level rise, mitigate the impacts of sea level rise, and protect the health, safety, and welfare of residents of the City by establishing regulations for addressing flooding and other hazards associated with sea level rise. The specific purposes of the Flood Plain/Sea Level Rise Overlay District are to:
Limit the potential impact of coastal flooding and erosion patterns on coastal development so as to minimize damage to and destruction of life and property and to reduce the necessity of public expenditure to protect future development from such hazards.
Adapt to a changing climate by requiring resilient design and upgrades in areas impacted by sea level rise.
Require adaptation strategies and best practices for long-term resilience.
Establish standards consistent with the priorities of the San Mateo County Flood and Sea Level Rise Resiliency District (Resiliency District).
Division IV: Overlays and Plan Districts
Division IV, Page 2 | South San Francisco Zoning Code | Public Review Draft Introduce flood-proof construction techniques and shoreline protection measures.
Steward the San Francisco Bay, Colma Creek, San Bruno Creek, and the natural habitat they provide.
Enhance South San Francisco waterways as ecological corridors, restoring creek ecologies and creating transitional habitat zones to build resilience and ecosystem services.
20.180.002 Applicability
The provisions of this chapter shall apply to all areas of the City within the Flood Plain/Sea Level Rise Overlay district. This area includes:
The area within the Federal Emergency Management Agency (FEMA) flood zone map;
The area identified in the General Plan as the 100-year flood plus the 2100 mid-level scenario of 36 inches sea level rise; and
The San Francisco Bay Shoreline area, defined by California Code of Regulations Section 10121 as the jurisdiction of the Bay Conservation and Development Commission (BCDC) within a 100-foot “Shoreline Band.”
In addition, the City Engineer or Chief Planner may require that standards of the Overlay apply to properties outside the Overlay District based on maps and other studies, which document the existence of potential flooding or sea level rise hazards that warrant evaluation.
20.180.003 Application Required
Site Clearance Required. Prior to issuance of a Building Permit, all new construction, repairs, or alterations must receive a Site Clearance pursuant to Chapter 20.470 (“Site Clearance”), to ensure that the proposed project is consistent with the applicable requirements of this section, except that the Chief Planner may grant an exception for normal maintenance or for required emergency projects to ensure the health and safety of the community.
Site Clearance Review Application Submittal. Application for Site Clearance must be accompanied by the following for review by the Chief Planner:
1. For any rehabilitation, installation of new electrical or mechanical systems, or any structural repair with an estimated cost that is less than 50 percent of the market value of the structure, a current elevation certificate sealed by a licensed design professional is required.
Division IV: Overlays and Plan Districts
Public Review Draft | South San Francisco Zoning Code | Division IV, Page 3
2. For any addition, any conversion of any non-habitable space to habitable space, or the construction or installation of a new accessory structure that requires a building permit:
a. A current elevation prepared by a licensed design professional; and b. A physical survey, performed after the effective date of the FIRMi that:
i. Accurately depicts current improvements on the property; and ii. Documents the type of flood (inundation, creek, and groundwater), and flood depth of flooding with FIRM reference.
3. For new construction and any substantial improvement of a principal structure:
a. A proposed site plan sealed by a design professional that provides:
i. Two topographic surveys of the property, such as a LiDAR or field survey, prepared by a licensed professional land surveyor:
one within 12 months of the application date and prior to construction, and one within 12 months of project completion.
Such survey shall be at the landowner or applicant’s expense and shall be conducted in consultation with City staff to be approved as compliant with City survey standards.
ii. The type of flood (inundation, creek, and groundwater), and flood depth of flooding with FIRM reference.
iii. Proposed grades, grading and stormwater management; iv. All proposed structures and improvements.
v. Proposed finished floor elevations of all structures. vi. The elevation of the bottom of the lowest horizontal structural member of the lowest floor of all structures.
vii. Landscape plan.
b. Elevations of the proposed development showing compliance with these floodplain regulations; and
c. For non-residential structures proposed to be flood-proofed, documentation of proposed flood-proofing showing compliance with the regulations of this chapter.
4. As a condition of project approval, the applicant shall execute an agreement with the City identifying the landowner’s ongoing maintenance obligations for the shoreline infrastructure approved as part of a development.
5. Any additional information deemed by the Chief Planner to be necessary to perform the required review.
Division IV: Overlays and Plan Districts
Division IV, Page 4 | South San Francisco Zoning Code | Public Review Draft Determination of Compliance. Prior to issuance of a Building Permit, a registered professional engineer retained by the applicant shall certify that the design, specifications, and plans for the construction of Shoreline infrastructure are in accordance with the requirements of this Chapter, FEMA guidance, and the Code of Federal Regulations (CFR) related to the mapping of areas protected by levee systems in place as of the application date. An applicant's proposal that meets the requirements of this chapter and the CFR, but is not consistent with the planned infrastructure project of the City and District, shall be permitted if the proposal is demonstrated to be a less or equally environmentally impactful practical alternative (including environmentally-beneficial features such as listed species habitat, marsh, open space, etc.).
20.180.004 Uses
The following uses are prohibited within the Flood Plain/Sea Level Rise Overlay District:
Emergency command centers/communications facilities.
Emergency shelters.
Fire stations.
Hospitals.
Health care facilities.
Schools.
Telecommunication facilities.
20.180.005 Development Standards
Standards for the Flood Plain/Sea Level Rise Overlay District are intended to prevent flood damage to buildings by elevating occupiable space, flood proofing areas beneath flood elevations, and promoting health and safety by preventing sensitive uses below the sea level rise elevation.
Construction Requirements. New construction or replacement of existing construction must be in conformance with Chapter 15.56 (“Flood Damage Prevention”) except where this chapter establishes a different requirement.
Building Height. Building height within the Flood Plain/Sea Level Rise Overlay District will be measured from the Sea Level Rise Base Flood Elevation (SLR-BFE). The SLRBFE is defined as or three feet above the 100 year FEMA flood elevation, or 77 inches above sea level.
Division IV: Overlays and Plan Districts
Public Review Draft | South San Francisco Zoning Code | Division IV, Page 5 Bay Access Buffer. A Bay Access Buffer extending 100 feet inland from the San Francisco Bay Shoreline is intended to provide an area to accommodate and maintain built and natural shoreline infrastructure for sea level rise protection, environmental enhancement, and public access trails. For the purposes of this Chapter, the San Francisco Bay Shoreline is defined by California Code of Regulations Section10121, which describes the jurisdiction of the Bay Conservation and Development Commission (BCDC) within a 100-foot “Shoreline Band.”
1. Building Encroachments. Building encroachments may be accommodated within the 100-foot Bay Access Buffer provided that the City determines that such encroachments do not inhibit a planned infrastructure project of the City and Resiliency District as of the application date.
2. Shoreline Access. Public access shall be maintained and developed within the Bay Access Buffer based on the City-adopted and BCDC-approved public access guidelines.
3. Trails Required. Where required by the San Francisco Bay Trail Project, the Bay Access Buffer must be improved with trails located an average of 75 feet from the Shoreline.
4. Trail Connectivity. Unless it is demonstrated to the satisfaction of City staff that no feasible alternative exists, any property with frontage on the Shoreline within the jurisdiction of the BCDC shall be required to provide, as a part of the on-site landscaping plan and Shoreline infrastructure, connectivity improvements by constructing a new or improved portion of the Bay Trail along the site, including improving access to the Bay Trail from and through the site. The trail shall be compliant with specifications of the City Public Works Department, BCDC, and San Francisco Bay Trail Project. Each trail segment shall connect directly to the trail segment of adjacent properties.
5. Maintenance. All areas improved for public access within the jurisdiction of BCDC shall be maintained by the property owner and shall be available to the public in perpetuity, as determined by the BCDC.
Creek Access Buffers. Creek Access Buffers are intended to provide an area to accommodate and maintain flood protection and public access trail infrastructure.
For properties with frontage on Colma Creek or San Bruno Creek, a minimum buffer zone of 35 feet from the top of creek bank is required to accommodate and maintain future infrastructure and a public access trail.
1. Building Encroachments. Building encroachments may be accommodated within the buffer zones provided that the City determines that such encroachments do not inhibit planned infrastructure projects of the City and Resiliency District as of the Application Date.
Division IV: Overlays and Plan Districts
Division IV, Page 6 | South San Francisco Zoning Code | Public Review Draft
2. Creek Access. Unless it is demonstrated to the satisfaction of City staff that no feasible alternative exists, any property with frontage on Colma Creek or San Bruno Creek shall be required to provide, as a part of the on-site landscaping plan, a paved public-access trail along the top of the bank for the portion of the creek bank on the site. The trail shall be compliant with specifications of the City Public Works Department and BCDC, if applicable. Each such trail segment shall connect directly to the creek bank on each adjacent property or a trail segment along the Shoreline (e.g., the Bay Trail).
Elevation of Lowest Floor. For structures not wholly within a levee or seawall system, the lowest floor of structures shall be built at or above the existing 100-year base flood elevation plus three feet of sea level rise. Spaces below the SLR-BFE are limited to access or vertical circulation structures; flood prevention measures, storage, and parking accessory to non-residential uses.
Mechanical and Electrical Equipment. Equipment, such as boilers, chillers, and air handlers for ventilation, shall be located on the roof to ensure operation during flooding.
Utilities. New or replacement water supply systems and/or sanitary sewer systems must be designed to minimize or eliminate infiltration of flood waters into the systems and discharges from the systems into flood waters. On-site waste disposal systems must be located to avoid impairment of water supply systems and/or sanitary sewer systems or contamination from them during flooding.
Site Grading.
1. Site grading shall include the importation of fill to raise the site adequate to allow positive drainage in a 10 year storm occurring at the 100 year flood elevation established by FEMA.
2. Finished slopes shall not exceed a maximum of 2:1.
Levees, and Floodwalls.
1. Any new portion of a levee above existing grade shall be sloped at least ten to one (10:1).
2. Along canals and creeks, armoring shall be living vegetation where possible.
3. Along the shoreline, armoring is restricted to natural materials.
4. Floodwalls may be used to provide additional protection only when used in conjunction with and on top of a levee.
Stormwater Runoff and Drainage.
Division IV: Overlays and Plan Districts
Public Review Draft | South San Francisco Zoning Code | Division IV, Page 7
1. All developments shall employ low-impact stormwater runoff techniques that mimic natural watershed processes that capture and treat stormwater runoff at its source, and reduce, filter, or slow runoff before entry into the storm drainage system. Systems may include drainage courses, swales, infiltration gardens, and trees to increase evapotranspiration.
2. One hundred percent of the drainage from impervious surfaces on the site shall be captured and retained on site with sufficient storage to keep the first
1.85 inches of rainwater from an individual rain event on site without discharging onto neighboring properties or rights-of-way unless a regional stormwater management system is available to serve the development and the specific discharges from the site into the system have been approved by the City Public Works Department. On-site retention may include infiltration, rainwater harvesting, or evapotranspiration.
Landscape Species. Planting palettes must:
1. Consist of a minimum 80 percent native species.
2. Reflect the composition of native habitat types.
Lighting. All lighting within the Flood Plain/Sea Level Rise Overlay District must be low intensity to reduce the amount of light reaching sensitive habitat. Also see Chapter 20.300.008 (“Lighting and Illumination”).
Impervious Areas. No net new impervious areas are permitted in designated parks and open spaces within the Flood Plain/Sea Level Rise Overlay District.
Connectivity. All on-site open spaces are to be connected with open spaces on adjacent parcels or rights-of-way, shoreline protection, or watershed management projects.
Riparian Area Protection. To minimize disturbance to the creek and vegetation, on the edge of the creek setback the project applicant shall erect a minimum four foot high construction fence prior to the issuance of a grading permit. The fence shall stay in place until a certificate of occupancy is issued.
Real Estate Disclosure of Hazards. In any contract for the sale of real estate located in the Floodplain/Sea Level Rise Overlay District indicated on the Overlays map adopted on file with the City of South San Francisco, the seller shall include in the contract a real estate disclosure of all hazards associated with anticipated sea level rise, geologic hazards, groundwater inundation, or coastal and fluvial flooding. Any site-specific analyses related to sea level rise must also be disclosed in real estate transactions.
Division IV: Overlays and Plan Districts
Division IV, Page 8 | South San Francisco Zoning Code | Public Review Draft Chapter 20.190 Reserved
Chapter 20.200 Reserved
Chapter 20.210 Reserved
Bay West Cove Specific Plan District to be deleted.
Chapter 20.220 Reserved
Gateway Specific Plan District to be deleted.
Chapter 20.230 Oyster Point Specific Plan District
No changes to this Chapter except for the addition of the following: Allowed uses are consistent with those of the BTP District.
Chapter 20.240 Reserved
Terrabay Specific Plan District to be deleted.
Chapter 20.250 Reserved
Transit Village Plan District to be deleted.
Chapter 20.260 Genentech Master Plan District
No changes to this Chapter except for the addition of the following: Allowed uses are consistent with those of the BTP District.
Chapter 20.270 Reserved
El Camino Real/Chestnut Avenue Area Plan District to be deleted.
Division IV: Overlays and Plan Districts
Public Review Draft | South San Francisco Zoning Code | Division IV, Page 9 Chapter 20.280 Reserved
Relevant content from the Downtown Station Area Specific Plan has been included in Chapter 20.090, Downtown Station Area Zoning Districts or in Chapter 20.310, Site and Building Design Standards.