Zoning
Zoning policies guide the siting and type of new developments or redevelopment in an area to avoid or address flood risks.
Potential Policy Areas
Green Stormwater Infrastructure
A city or jurisdiction's green stormwater infrastructure policy provides a framework describing where and how to integrate green stormwater measures that help to reduce flooding and provide a nature-based approach to stormwater management. This may be part of permitting, zoning and other development approvals.
Benefits & Function
Green infrastructure helps to reduce the need for treated stormwater, and reduces the quantity of water and pollutants flowing into local creeks and San Francisco Bay.
Considerations
Green stormwater infrastructure may be integrated into a mixed system of engineered, "grey" stormwater, and should be part of any new roadway and development efforts.
Uses for Policy
New Development, Existing
Overlay Zones
Overlay zones are a zoning mechanism that creates additional land use regulations or building standards to base zones, and can be used to mitigate flooding and erosion.
Benefits & Function
Overlay zones offer local governments the ability to easily regulate areas that have increased risk of riverine flooding, sea level rise, wildfire, and urban heat. They are flexible and easily applied to site-specific vulnerabilities. They can be implemented alongside other policy measures as well as with nature-based solutions.
Considerations
Existing zoning laws and regulations for different land uses must be kept in mind when considering adding an overlay zone. Additional conditions and restrictions may have to be added over time as the climate and policy changes.
Uses for Policy
Existing, New, Redevelopment,
Setbacks & Buffers
Setback and buffer policies require that structures are built a certain distance behind the shoreline to reduce impacts of sea level rise and ensure that certain natural environments be maintained and remain undeveloped.
Benefits & Function
Buildings will have longer life expectancies through the protective distance from rising tides and riverine flooding. These policies will protect new buildings and structures from new or increasing hazards. Natural environments can flourish with less development. Allowing space for tidal transition zones will limit sea level rise impacts and create greater habitat adaption and resilience.
Considerations
Setbacks are harder to implement in areas that are already developed or that are set to be developed, and are most successful in undeveloped land. Setbacks are determined by jurisdiction, type of building, type of shoreline, etc. In the Bay Area, the Bay Conservation and Development Commission has control of a 100ft band around the Bay where no development can occur without a permit.
Uses for Policy
New development
Clustering
Clustering is a zoning policy that organizes buildings in close proximity to each other in order to minimize urban sprawl and human impact on surrounding environments.
Benefits & Function
Clustering buildings creates open, usable space with more permeable area to allow filtration through soils and limit flooding. Clustering also decreases stress on natural ecosystems along the shoreline.
Considerations
Clustering only applies to new developments or redeveloping areas. Consider height-related building codes in order to use land efficiently.
Uses for Policy
Redevelopment
Rebuilding and Redevelopment Restrictions
Rebuilding and Redevelopment Restrictions limit the reconstruction of buildings destroyed by hazards such as flooding events or wildfires or can ensure structures are rebuilt with flood and climate risk in mind.
Benefits & Function
Redevelopment restrictions can decrease redevelopment in high risk areas.
Considerations
Rebuilding and redevelopment policies can be implemented through zoning and overlay zones. They can also be triggered through building codes that elevate structures and through general flood protection strategies.
Uses for Policy
Existing development
Geologic Hazard Abatement Districts
Geologic Hazard Abatement Districts are independent governmental districts that can assess properties within a defined area and dedicate the revenue to abating or controlling hazards such as landslides, earthquakes, and erosion.
Benefits & Function
The maintenance and monitoring of hazards and other upgrades needed for flood protections means that GHADs provide long-term security of property values or a form of insurance for probable geologic issues.
Considerations
To establish a GHAD, 10% of property owners within the proposed district must petition for its creation; assessments then must go through the Proposition 218 process and be adopted by the city council/board of supervisors. The GHAD is governed by a Plan of Control and a Board of Directors, often an existing legislative body.
As with other types of tax assessments, GHADs can pool resources for adaptation that would otherwise not be deployed in a coordinated fashion. But they can also be regressive, as the basis is typically property tax, which some owners can more readily afford than others. These resources should ideally be put toward an adaptation strategy or vision that has broad public and governmental support, or else they could result in payment for short-term solutions at the expense of a more holistic and resilient approach. GHADs were enabled by California state law in 1979 and are exempt from Local Agency Formation Commissions (LAFCOs) and CEQA. One disadvantage is that they cannot be easily dissolved after they are formed.
Uses for Policy
New Development