GRRA_Habitat_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). Habitat Areas show areas sensitive to development due to the presence of strong habitat value, wildlife corridors, or aquatic resources. Sensitive habitats are critical for biodiversity conservation and ecosystem functioning, particularly where growth pressure may lead to habitat degradation. Conserving natural areas helps buffer communities from climate hazards like flooding and wildfires, while preserving carbon-rich landscapes that mitigate greenhouse gas emissions. Several data sources inform the Topic Areas within the data category of Habitat: Habitat 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 InstituteData sources are merged by Topic Area, and this dataset counts the number of overlapping Topic Areas for impacted locales in the region (Habitat Value, Wildlife Corridors, Aquatic Resources). Scores range from 1 to 3. This dataset is accompanied by similar versions for Climate Hazards and Agriculture, as well as an overall summary of overlaps amongst the topic areas within the three datasets. 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 Habitat category: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, In addition to ACE datasets, The California Coastal Commission’s Critical Coastal Areas (2021) dataset is included, 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.