i17 Delta Levees Anatomy 2007

The use of high-resolution LiDAR, and the products derived from it, allow for levee anatomy to be captured for the surveyed area. The resulting data is a catalog of precise levee location and components. This data can further be used for levee maintenance and management, flood modeling and prediction, as well as levee inventories. In the Delta Anatomy Mapping Project all levee anatomies were delineated using slope grids built from available LIDAR data points. LIDAR data points were converted to digital elevation models and subsequently into slope grids. Thresholds were identified that capture the levee crown, levee landside, levee waterside, ramps and toe ditches. Visual interpretations of slope thresholds were used in conjunction with heads-up digitizing to maintain smooth boundaries at a scale of 1:550. The delineation thresholds were derived from a combination of mapping scale, slope grid resolution and slope thresholds used for each anatomy classification. All anatomy has gone through an internal quality control process to ensure a minimum accuracy of +/- 3 feet. Anatomy was further reviewed and tested by DWR for compliance with an interpretive mapping standard of 80% accuracy. This data depicts the levee anatomy at the time of the LiDAR survey (2007) and are only accurate for that time. Users should be aware that temporal changes may have occurred since this data set was created and some parts of this data may no longer represent actual surface conditions. This version created by mapping from the 2007 Delta LIDAR. 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 3.1, dated September 11, 2019. 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 sent to GIS@water.ca.gov