Data Sources

Watershed-Scale Assessment

Groundwater recharge potential:  Identified areas with opportunities for groundwater recharge (low, medium, high potential).

Data sources (local and national):

Groundwater bearing areas (from SAWPA): http://www.arcgis.com/home/
Hydrologic Soil Group data from NRCS Soil Survey Geography Database (SSURGO): https://websoilsurvey.sc.egov.usda.gov/App/
HUC-12 Watersheds from USGS Watershed Boundary Dataset: https://www.usgs.gov/core-science-systems/ngp/

Water quality impairment:  Identifies areas adjacent to impaired water bodies. Impaired waters are defined as those on the USEPA 303(d) list.

Data sources (national):

Rivers and streams data from National Hydrography Dataset: https://www.usgs.gov/core-science-systems/ngp/national-hydrography/
USEPA 303(d) Listed Impaired Waters: https://www.epa.gov/waterdata/waters-geospatial-data-downloads
HUC-12 Watersheds from USGS Watershed Boundary Dataset: https://www.usgs.gov/core-science-systems/ngp/national-hydrography/

Flood zones:  Identifies areas that would be inundated by a 100- or 500-year flood event.

Data sources (national):

100- and 500-year flood zones: https://hazards.fema.gov/femaportal/wps/portal/NFHLWMS
HUC-12 Watersheds from USGS Watershed Boundary Dataset: https://www.usgs.gov/core-science-systems/ngp/

Disadvantaged communities:  Identifies areas within AB 1550 and SB 535 disadvantaged community boundaries from CalEnviroScreen 3.0.

Data source (state):

From OEHHA: https://oehha.ca.gov/calenviroscreen/maps-data

CI Parcels:  Identifies commercial and industrial parcels.

Data source:

Parcel boundaries with parcel land use classification (provided by SAWPA, often available from county)

Potential Parcel-Level Water Benefits

Water supply benefit?  This parcel has potential to capture stormwater for recharge or direct use and/or parcel is located in an area with the highest irrigation demand (based on evapotranspiration). Stormwater management improvements and/or replacement of cool-season turfgrass with climate-appropriate plants on this parcel could provide a greater magnitude of water supply benefits than on other parcels.

Data Sources:

Recharge vs. direct use analysis:

Groundwater bearing areas (from SAWPA): http://www.arcgis.com/home/item.html?id=429e08acb1b4494596f6896e06881daa
Hydrologic Soil Group data from NRCS Soil Survey Geography Database (SSURGO): https://websoilsurvey.sc.egov.usda.gov
HUC-12 Watersheds from USGS Watershed Boundary Dataset: https://www.usgs.gov/core-science-systems/
Parcel boundaries with parcel land use classification (provided by SAWPA, typically available from county)

Turf replacement analysis:

Turf Area by Parcel: File geodatabase with Meter Service Area (MSA) boundaries, land use classification. and estimated square feet of area for total irrigated area and vegetation classes (including turf). Vegetation classification was conducted through SAWPA using 3-inch resolution, 4 band aerial imagery flown in June of 2015. Data provided by Santa Ana Watershed Project Authority.
Reference Evapotranspiration Zone: Data obtained through previous request to California Department of Water Resources.

Water quality benefit?  This parcel is located in a subwatershed with impaired water(s) and could benefit more from improvements to surface water quality than parcels not in subwatersheds with impaired water(s). Impaired waters are defined as those on the USEPA 303(d) list.

Data sources (national and regional):

Rivers and streams data from National Hydrography Dataset: https://www.usgs.gov/core-science-systems/ngp/
USEPA 303(d) Listed Impaired Waters: https://www.epa.gov/waterdata/waters-geospatial-data-downloads
Parcel boundaries with parcel land use classification (provided by SAWPA, typically available from county)

Flood risk benefit?  This parcel is located in a 100-year or 500-year flood zone and could benefit more from flood risk management practices than parcels outside the flood zone.

Data sources (national and regional):

FEMA Flood Zone Data: https://www.fema.gov/national-flood-hazard-layer-nfhl
Parcel boundaries with parcel land use classification (provided by SAWPA, typically available from county)

Disadvantaged community?  This parcel is located within AB 1550 and SB 535 disadvantaged community boundaries from CalEnviroScreen 3.0. These communities are more vulnerable than other communities to water-related risks such as flooding and water quality impairments.

Data source (state):

From OEHHA https://oehha.ca.gov/calenviroscreen/maps-data

Turf Area (ft2):  The parcel turf area represents the water saving potential of replacing turf with climate-appropriate plants, thereby boosting water supply reliability. More broadly, turf replacement can reduce chemical usage and allow for stormwater infiltration, storage, and/or detention.

Data Source (regional):

Provided by Santa Ana Watershed Project Authority.