The 2003 Solano County land use survey data set was developed by DWR through its Division of Planning and Local Assistance which, following reorganization in 2009, is now called Division of Statewide Integrated Water Management (DSIWM). The data was gathered using aerial photography and extensive field visits, the land use boundaries and attributes were digitized, and the resultant data went through standard quality control procedures before finalizing. The land uses that were gathered were detailed agricultural land uses, and lesser detailed urban and native vegetation land uses. The data was gathered, digitized and quality control procedures were performed jointly by staff at DWR’s DSIWM headquarters and North Central Region. Important Points about Using this Data Set: 1. The land use boundaries were drawn on-screen using orthorectified imagery. They were drawn to depict observable areas of the same land use. They were not drawn to represent legal parcel (ownership) boundaries, or meant to be used as parcel boundaries. 2. This survey was a "snapshot" in time. The indicated land use attributes of each delineated area (polygon) were based upon what the surveyor saw in the field at that time, and, to an extent possible, whatever additional information the aerial photography might provide. The DWR land use attribute structure allows for up to three crops per delineated area (polygon). Fields outside of the Montezuma Hills were surveyed in May to map winter grain and again during the summer to collect data on other annual and perennial crops. In the cases where there were crops grown before the survey took place, the surveyor may or may not have been able to detect them from the field or the photographs. For crops planted after the survey date, the surveyor could not account for these crops. Thus, although the data is very accurate for that point in time, it may not be an accurate determination of what was grown in the fields for the whole year. If the area being surveyed does have double or multicropping systems, it is likely that there are more crops grown than could be surveyed with a "snapshot". 3. If the data is to be brought into a GIS for analysis of cropped (or planted) acreage, two things must be understood: a. The acreage of each field delineated is the gross area of the field. The amount of actual planted and irrigated acreage will always be less than the gross acreage, because of ditches, farm roads, other roads, farmsteads, etc. Thus, a delineated corn field may have a GIS calculated acreage of 40 acres but will have a smaller cropped (or net) acreage, maybe 38 acres. b. Double and multicropping must be taken into account. A delineated field of 40 acres might have been cropped first with grain, then with corn, and coded as such. To estimate actual cropped acres, the two crops are added together (38 acres of grain and 38 acres of corn) which results in a total of 76 acres of net crop (or planted) acres. 4. Not all land use codes will be represented in the survey. 5. This survey contains areas where land use data was not collected. These are indicated by “NS” in the class1 field. The non-surveyed area is located primarily in the Montezuma Hills near the Sacramento-San Joaquin River Delta, but also includes a few polygons outside that area. Many fields in the Montezuma Hills are usually planted to non-irrigated grain, so using only the fields mapped as “grain” to calculate acreage in this survey is likely to undercount the actual acres of grain grown in Solano County in 2003. 6. Sources of the irrigation water are included in this land use data. Water sources were determined through a combination of noting groundwater wells in the field and using the boundaries of Solano Irrigation District, Maine Prairie Water District, Reclamation District 2068 and the boundary of the Delta Service Area. We received the water district and Reclamation District boundaries from Solano Irrigation District in November of 2004. The boundaries had been recently updated at that time. There are likely to be individual fields whose actual water source is different from the source designated on our map because we did not verify water sources by contacting each grower.

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 3.3, dated April 13, 2022. 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. The official DWR GIS steward for the statewide compilation of this data is Mohammad Mostafavi, who may be contacted at Mohammad.Mostafavi@water.ca.gov. See the CADWR Land User Viewer (gis.water.ca.gov/app/CADWRLandUseViewer) for the most current contact information. Comments, problems, improvements, updates, or suggestions should be forwarded to the official GIS steward as available and appropriate.

The 2003 Solano County land use survey data set was developed by DWR through its Division of Planning and Local Assistance which, following reorganization in 2009, is now called Division of Statewide Integrated Water Management (DSIWM). The data was gathered using aerial photography and extensive field visits, the land use boundaries and attributes were digitized, and the resultant data went through standard quality control procedures before finalizing. The land uses that were gathered were detailed agricultural land uses, and lesser detailed urban and native vegetation land uses. The data was gathered, digitized and quality control procedures were performed jointly by staff at DWR’s DSIWM headquarters and North Central Region. Important Points about Using this Data Set: 1. The land use boundaries were drawn on-screen using orthorectified imagery. They were drawn to depict observable areas of the same land use. They were not drawn to represent legal parcel (ownership) boundaries, or meant to be used as parcel boundaries. 2. This survey was a "snapshot" in time. The indicated land use attributes of each delineated area (polygon) were based upon what the surveyor saw in the field at that time, and, to an extent possible, whatever additional information the aerial photography might provide. The DWR land use attribute structure allows for up to three crops per delineated area (polygon). Fields outside of the Montezuma Hills were surveyed in May to map winter grain and again during the summer to collect data on other annual and perennial crops. In the cases where there were crops grown before the survey took place, the surveyor may or may not have been able to detect them from the field or the photographs. For crops planted after the survey date, the surveyor could not account for these crops. Thus, although the data is very accurate for that point in time, it may not be an accurate determination of what was grown in the fields for the whole year. If the area being surveyed does have double or multicropping systems, it is likely that there are more crops grown than could be surveyed with a "snapshot". 3. If the data is to be brought into a GIS for analysis of cropped (or planted) acreage, two things must be understood: a. The acreage of each field delineated is the gross area of the field. The amount of actual planted and irrigated acreage will always be less than the gross acreage, because of ditches, farm roads, other roads, farmsteads, etc. Thus, a delineated corn field may have a GIS calculated acreage of 40 acres but will have a smaller cropped (or net) acreage, maybe 38 acres. b. Double and multicropping must be taken into account. A delineated field of 40 acres might have been cropped first with grain, then with corn, and coded as such. To estimate actual cropped acres, the two crops are added together (38 acres of grain and 38 acres of corn) which results in a total of 76 acres of net crop (or planted) acres. 4. Not all land use codes will be represented in the survey. 5. This survey contains areas where land use data was not collected. These are indicated by “NS” in the class1 field. The non-surveyed area is located primarily in the Montezuma Hills near the Sacramento-San Joaquin River Delta, but also includes a few polygons outside that area. Many fields in the Montezuma Hills are usually planted to non-irrigated grain, so using only the fields mapped as “grain” to calculate acreage in this survey is likely to undercount the actual acres of grain grown in Solano County in 2003. 6. Sources of the irrigation water are included in this land use data. Water sources were determined through a combination of noting groundwater wells in the field and using the boundaries of Solano Irrigation District, Maine Prairie Water District, Reclamation District 2068 and the boundary of the Delta Service Area. We received the water district and Reclamation District boundaries from Solano Irrigation District in November of 2004. The boundaries had been recently updated at that time. There are likely to be individual fields whose actual water source is different from the source designated on our map because we did not verify water sources by contacting each grower.

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 3.3, dated April 13, 2022. 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. The official DWR GIS steward for the statewide compilation of this data is Mohammad Mostafavi, who may be contacted at Mohammad.Mostafavi@water.ca.gov. See the CADWR Land User Viewer (gis.water.ca.gov/app/CADWRLandUseViewer) for the most current contact information. Comments, problems, improvements, updates, or suggestions should be forwarded to the official GIS steward as available and appropriate.