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NCRO Land & Water Use & Conservation

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Main Phone: (916) 376-9600

Street Address:

3500 Industrial Blvd., Suite 131 West Sacramento, CA 95691

Mailing Address:

Post Office Box 942836 Sacramento, CA 94236

Land Use Survey Program

The Land Use Program at DWR develops and analyzes data on irrigated acreage primarily for purposes of the California Water Plan Update. The information available from this program is shared with other agencies, organizations, educational institutions, and the public.

Counties within the North Central Region boundary are surveyed on a rotating schedule, typically every seven or more years. North Central Region Office study areas encompass 27 counties in their entirety or parts of. Counties with substantial amounts of irrigated agricultural acreage (Sacramento Valley and Sacramento-San Joaquin Delta counties) are surveyed approximately every seven to ten years; counties with less agricultural development are surveyed less often. Land Use Surveys identify and quantify agricultural land by crop, water source and irrigation types as well as general urban development, and wetlands. For non-survey years, North Central Region Office Land and Water Use Scientists estimate annual agricultural land use acreage using information available from County Agriculture Commissioner Crop Reports.

Aerial photography or imagery of the county being surveyed is obtained and used to identify field boundaries and locate the fields during the ground-truthing process. The county being surveyed is subdivided into study areas based on geographic features in order to facilitate the survey. Using ortho-rectified aerial imagery as the baseline, field boundaries are digitized using geographic information system (GIS) software. The fields are visited and information collected includes: crop type, and, if readily identifiable, water source, irrigation method, and agricultural groundwater well and lift pump locations. For urban land use generally only the larger industrial, commercial, residential or landscape areas are delineated and quantified. Quality control maintains the continuity of fields between study areas. Using ArcGIS, all the study areas of the county are merged to create a county wide mosiac that can be overlapped with various geographic boundaries. Acreages are calculated for each field and geographic area. Database tables are exported from GIS to database software for the production of hard copy tabulations. The database is designed as a standard template report for all counties surveyed and is used to compare data from survey to survey. These procedures are changed or updated as new or improved technology is developed in the GIS and computer program industry.

Information collected by the surveys is used to estimate present and future land and water uses for the California Water Plan updates (DWR Bulletin 160 series). DWR land use data are useful for other purposes including studies estimating groundwater use, routing of agricultural water supplies, depletion of water supplies, agricultural drainage, agricultural water quality, identification of wetlands, water transfer potential, and urban encroachment.

Accessing Previous surveys: You can access past survey information at the Land Use Survey website.

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