Dataset represents centerlines of major water project canals that are managed by local area government agencies or entities. This dataset does not contain major State or Federal canals. The original data were from many sources including NHD,USBR,DWR,and contained errors in the attributes and locations. These errors were rectified by Jeff Galef of DWR Delta Levees Special Investigations Branch, using 2005 and 2006 NAIP imagery and Central Valley Aerials Express. These updates were as of 2009. Conflicts between this original data source and any new linework added was resolved using NAIP imagery from 2012. Digitizing was done at approximately 1:9000 scale. Many unnamed canals were identified using USGS topo maps and ESRI Street Map. Additional canal features were added in November 2017 which were inadvertently not included in the initial dataset.