GRRA_Consolidated_boundary_scag

The Green Region Resource Areas (GRRAs) dataset consists of information on natural hazards, sensitivities, farmland, tribal nations, military installations, and natural assets. The GRRA datasets are developed to support coordinating regional land use with transportation strategies and address the region’s growth and sustainability challenges to protect the region’s natural assets and reduce future risks from climate change. GRRAs are organized into three Data Categories with seven Topic Areas: Climate Hazards (flood hazard, sea level rise, wildfire risk), Habitat (habitat value, wildlife corridors, aquatic resources), and Agriculture (farmland). Several data sources inform the Topic Areas within the Consolidated MapClimate HazardsFlood Hazard National Flood Hazard Layer (NFHL), 2025, FEMACoastal Inundation (Sea Level Rise) Sea Level Rise (3.5 Feet), 2025, NOAA Office for Coastal ManagementWildfire Hazard Fire Hazard Severity Zones (FHSZs) Local Responsibility Areas, 2025, Cal FIRE Fire Hazard Severity Zones (FHSZs) State Responsibility Areas, 2024, Cal FIRE Priority Landscape – Reduce Wildfire Risk to Ecosystem Services, 2018, Fire and Resource Assessment Program (FRAP) at Cal FIRE Priority Landscape – Reduce Wildfire Risk to Communities, 2018, Fire and Resource Assessment Program (FRAP) at Cal FIRE Wildland Urban Interface and Intermix (WUI), 2025, Cal FIREHabitatHabitat ValueSpecies Biodiversity, Areas of Conservation Emphasis (ACE), 2021, CDFW Terrestrial Climate Change Resilience, Areas of Conservation Emphasis (ACE), 2021, CDFW Terrestrial Connectivity, Areas of Conservation Emphasis (ACE), 2025, CDFW Critical Coastal Areas, 2021, California Coastal CommissionWildlife CorridorsEssential Connectivity Areas - California Essential Habitat Connectivity (CEHC), 2025, CDFWSouth Coast Missing Linkages, 2008, South Coast WildlandsAquatic ResourcesNational Wetlands Inventory (NWI) Riparian, 2024, USFWSNational Wetlands Inventory (NWI) Wetlands, 2024, USFWSCalifornia Aquatic Resources Inventory (CARI), 2025, San Francisco Estuary InstituteAgricultureFarmlandFarmland Mapping and Monitoring Program (FMMP), 2022, California Department of ConservationCalifornia Williamson Act Enrollment, 2024, California Department of Conservation The following datasets are a subset of the Green Region Resource Areas (GRRAs). The GRRAs dataset consists of information on natural hazards, sensitivities, farmland, tribal nations, military installations, and natural assets. The GRRA datasets are developed to support coordinating regional land use with transportation strategies and address the region’s growth and sustainability challenges to protect the region’s natural assets and reduce future risks from climate change.The following datasets are included within the consolidated map:Flood Hazard - Flood hazards are a foundational GRRA category because they highlight locations where development would face elevated risks and would not meet National Flood Insurance standards. The National Flood Hazard Layer (NFHL) (2025) is FEMA’s digital geospatial database that consolidates all Flood Insurance Rate Map (FIRM) information and Letters of Map Revisions (LOMRs). It depicts areas of flood risk, including Special Flood Hazard Areas (SFHAs) such as 1-percent-annual-chance flood zones (e.g., A, AE, AH, AO, A99, VE). The definitions for these zones can be found at https://www.fema.gov/flood-zones. FEMA prepares the flood maps to show the extent of flood hazard in a flood prone community by conducting engineering studies called ‘Flood Insurance Studies (FISs).’ From the study, FEMA delineates areas subject to inundation by a flood that has a 1 percent or greater chance of being equaled or exceeded during any given year. This type of flood is commonly referred to as the 100- year flood or base flood. The 100-year flood has a 26 percent chance of occurring during a 30 year period, the length of many mortgages. The 100-year flood is a regulatory standard used by Federal and most State agencies to administer floodplain management programs. The flood maps developed by FEMA are primary tools for state and local governments to mitigate the effects of flooding in their communities. The data are available to the public at FEMA’s Map Service Center (https://msc.fema.gov/portal/home). Please note that the information included in this book includes only 100-year flood data. Coastal Inundation (Sea Level Rise) - Sea level rise represents a growing risk for California’s coastline and is a required consideration for resource areas under SB 375. The Sea Level Rise Data was obtained from NOAA’s Office for Coastal Management (2025) as part of its Sea Level Rise and Coastal Flooding Impacts Viewer, a screening-level tool designed to visualize potential inundation under multiple scenarios. Please note the information included in this book includes only the 3.5-foot sea level rise inundation scenario. This dataset uses a modified bathtub approach that incorporates a Digital Elevation Model (DEM) and a tidal surface model based on Mean Higher High Water (MHHW). Wildfire Hazard - Wildfire represents one of the most critical hazards for Southern California communities, particularly where human development overlaps with fire-prone vegetation. Given the increasing frequency and severity of wildfires under climate change, the GRRA update incorporates multiple datasets to capture risks to both people and ecosystems. Data sources include several Cal FIRE datasets that assess wildfire risk and priority areas for mitigation. The Fire Hazard Severity Zones (FHSZs) for Local Responsibility Areas (2025) and State Responsibility Areas (2024) define wildfire hazard based on fire history, existing and potential fuel (natural vegetation), predicted flame length, blowing embers, terrain, and typical fire weather, with zones classified as Moderate, High, or Very High. The Priority Landscape – Reduce Wildfire Risk to Ecosystem Services by Cal FIRE (2018) identifies watersheds and forestlands most in need of treatment to reduce risks to ecological functions such as carbon storage, timber, water supply, and large tree habitat. The Priority Landscape – Reduce Wildfire Risk to Communities by Cal FIRE (2018) highlights lands where people and infrastructure are most vulnerable to wildfire, based on the intersection of housing density and FHSZs. Finally, the Wildland Urban Interface (WUI) dataset (2025) maps areas of California’s WUI by classifying lands into Interface and Intermix according to housing density, vegetation cover, and Fire Hazard Severity Zones. Habitat Value - The Habitat Value topic includes the following datasets from CDFW’s Areas of Conservation Emphasis (ACE). Note that only the most sensitive areas from these datasets were included in GRRAs: Species Biodiversity (2021), which summarizes California’s biodiversity based on occurrence and distribution data for amphibians, aquatic macroinvertebrates, birds, fish, mammals, plants, and reptiles; Terrestrial Climate Change Resilience (2021), which shows the probability that a location may serve as climate-change refugia. Climate-change refugia are areas relatively buffered from the effects of climate change, where conditions will likely remain suitable for the current array of plants and wildlife; Terrestrial Connectivity (2025), which summarizes connectivity by mapping corridors and linkages near large, contiguous natural areas; and, Additionally, apart from ACE datasets, it includes the California Coastal Commission’s Critical Coastal Areas (2021), which identifies coastal watersheds where high-value waters are threatened by polluted runoff. Wildlife Corridors - CDFW’s Essential Connectivity Areas (2025) depicts essential areas for ecological connectivity between habitat blocks that support native biodiversity. This coarse-scale map was based primarily on the concept of ecological integrity, rather than the needs of particular species. Essential Connectivity Areas are placeholder polygons that can inform land-planning efforts, but that should eventually be replaced by more detailed Linkage Designs, developed at finer resolution based on the needs of particular species and ecological processes. It is important to recognize that even areas outside of Essential Connectivity Areas support important ecological values that should not be “written off” as lacking conservation value. Additionally, the South Coast Wildlands’ South Coast Missing Linkages (2008) dataset delineates linkage boundaries identified by the South Coast Missing Linkages project. The South Coast Missing Linkages project was a collaborative inter-agency effort to identify and conserve the highest priority linkages in the South Coast Ecoregion. Linkage designs were developed through landscape permeability analyses that modeled least-cost corridors (best potential route) between protected areas for 109 focal species based on vegetation, topography, elevation, and road density layers at 30-meter resolution.Aquatic Resources – The USFWS National Wetlands Inventory (NWI) Riparian (2024) maps riparian habitats in the western U.S. while the USFWS NWI Wetlands (2024) maps wetlands and deepwater habitats. The San Francisco Estuary Institute’s California Aquatic Resources Inventory (CARI) (2025) depicts wetlands, streams, and riparian areas. Farmland - Farmland is an essential GRRA dataset, reflecting both their economic value and their role in regional sustainability, food security, and climate resilience. Protecting agricultural lands helps reduce sprawl, preserve carbon sequestration potential, and maintain the viability of California's farming economy. The Farmland Mapping and Monitoring Program (FMMP) (2022) provides a statewide inventory of agricultural land, mapping farmland and grazing land at a minimum unit of 10 acres. For the purposes of mapping GRRAs, only prime farmland, farmland of statewide importance, farmland of local importance, unique farmland, and grazing land were factors carried through to the dataset. The California Williamson Act Enrollment (2024) identifies lands under Williamson Act and Farmland Security Zone contracts, though it does not necessarily provide information as to the location of Agricultural Preserves within each county.