Data contains historical polygons of in-channel islands within the Sacramento San Joaquin Delta. Data consists of merged datasets from 1929, 1940, 1949, 1952, 1995, 2002, and 2017. The 2017 polygons are digitized from the 2017 Delta LiDAR imagery by the Division of Engineering, Geomatics Branch, Geospatial Data Support Section. The older pre-2017 polygons were all digitized by staff in the Delta Levees Program. Data can be queried for a single year or date range using the 'Year' field. Historical data was compiled and merged from datasets provided by the Delta Levees program. Data coverage differs between years. Absences or gaps in historical data may occur. Older acquisitions generally have a smaller footprint than recent imagery acquisitions. The 2017 in-channel islands cover the Legal Delta, and also include Chipps Island.

This dataset, (i06_SingleBeam_Bathymetry) is a feature dataset containing point feature classes with single beam bathymetric data collected by California Department of Water Resources and other entities.

This feature service captures Ecosystem metrics identified for monitoring the status and changes based on projects & activities occurring in the Systemwide Planning Area (SPA). The EcoMetric_PT (point) service includes Stressors – Fish Passage Barriers. The EcoMetric_Line (line) service includes Natural Bank, SRA Cover, Stressors – Revetment, and Stressors – Levees. The EcoMetric_Poly (polygon) service includes Floodplain Inundation, River Meander Potential, Habitat – Riparian, Habitat – Marsh and Wetlands and Stressors – Invasive Plants. For a detailed description of these metrics, please refer to the Conservation Strategy document linked below in the purpose section.

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"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." -this from the 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

This dataset, (i06_SingleBeam_Bathymetry) is a feature dataset containing point feature classes with single beam bathymetric data collected by California Department of Water Resources and other entities.

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This dataset, (i06_SingleBeam_Bathymetry) is a feature dataset containing point feature classes with single beam bathymetric data collected by California Department of Water Resources and other entities.

This dataset, (i06_SingleBeam_Bathymetry) is a feature dataset containing point feature classes with single beam bathymetric data collected by California Department of Water Resources and other entities.