This dataset represents the 1979 Delta Significant Resources Areas distributed in the 1979 Delta Environmental Atlas, produced by USACE. Intended to assess desirability of certain locations within the Delta for environmental attention. "This section identifies those areas in the Delta which because of their resource value should receive special consideration. Those areas...have been classified as Significant Resource Areas. These areas were selected based on several factors, which include significant areas of habitat, the presence of endangered plant or animal species, relative abundance of similar areas within the Delta and State, aesthetic and recreation value, concentrations of archaelogical or historical sites, level of present disturbance, and potential for future disturbance. In evaluating Delta lands to determine Significant Resource Areas, information was obtained from several data sources including consultations with individuals from various State, federal, local, and private organizations. Each area identified as having potential value was inspected using aerial photographs, in the field, or both." - Delta Environmental Atlas, published 7/1979, by USACE. References to the DMRP in the attribute table refer to the Delta Master Recreation Plan. 1979 Delta Significant Resource Areas were made digital by heads up digitizing registered scanned pages from 1979 Delta atlas. About the scanned maps from the Atlas: Digital images were clipped prior to warping to reduce risk of error during processing due to excess background. Digital clipped images were registered to USGS DOQQ's in ArcView 3.x(ESRI) utilizing Imagewarp 2.x extension. 23 October, 2002, Projection: UTM meters zone 10, nad 83. Accuracy within acceptable 7.5 Minute USGS map accuracy standards (1:24000 scale). For this set, the minimum number of control points used was 10 with an average of 12 to 15 points used. The pixel size for this set is 27.0 feet per pixel The associated data are considered DWR enterprise GIS data, which meet all appropriate requirements of the DWR Spatial Data Standards, specifically the DWR Spatial Data Standard version 3.2, dated September 10, 2021. DWR makes no warranties or guarantees — either expressed or implied — as to the completeness, accuracy, or correctness of the data. DWR neither accepts nor assumes liability arising from or for any incorrect, incomplete, or misleading subject data. Comments, problems, improvements, updates, or suggestions should be forwarded to gis@water.ca.gov as available and appropriate.

This dataset represents the 1977 Delta Habitat Types that were distributed in the 1979 Delta Environmental Atlas, produced by USACE. 1977 Delta Habitat Types were made digital by heads up digitizing registered scanned pages from 1979 Delta Environmental Atlas, produced by USACE. "The Habitat Types & Vegetation section delineates on 1 inch to 1000 foot scale aerial photographs the habitat types found in the Delta, described according to the classification system of the US Fish & Wildlife Service. Thirteen habitat types are defined in this Atlas. The associated data are considered DWR enterprise GIS data, which meet all appropriate requirements of the DWR Spatial Data Standards, specifically the DWR Spatial Data Standard version 3.2, dated September 10, 2021. DWR makes no warranties or guarantees — either expressed or implied — as to the completeness, accuracy, or correctness of the data. DWR neither accepts nor assumes liability arising from or for any incorrect, incomplete, or misleading subject data. Comments, problems, improvements, updates, or suggestions should be forwarded to gis@water.ca.gov as available and appropriate.

The Natural Communities Commonly Associated with Groundwater (NCCAG) dataset is a compilation of phreatophytic vegetation, regularly flooded natural wetlands and riverine areas, and springs and seeps extracted from 48 publicly available state and federal agency datasets. Two habitat classes are included in the dataset: wetland features commonly associated with the surface expression of groundwater under natural, unmodified conditions; and vegetation types commonly associated with the sub-surface presence of groundwater (phreatophytes). The NCCAG dataset began as an amalgamation of vegetation and wetland datasets with different scales, resolutions, attribute details, and classifications. A working group comprised of DWR, California Department of Fish and Wildlife (CDFW) and The Nature Conservancy (TNC) further reviewed the vegetation and wetland datasets and conducted a screening process to identify the vegetation and wetland types considered to be commonly associated with groundwater (Klausmeyer et al., 2018). The NCCAG dataset can be used as a starting point to investigate and identify groundwater dependent ecosystems (GDEs) within a groundwater basin. Identifying GDEs requires detailed understanding of the land use, groundwater levels, hydrology, and geology of a location. This comprehensive understanding of geology, hydrology, and biology is not available at the statewide scale. Further investigation and verification of the connection and dependence between groundwater and mapped vegetation and wetlands at a local scale may be needed for water managers in sustainable groundwater management planning.