Tuesday, February 22, 2022 from 5:30 PM to 7:00 PM PST
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AEG Sacramento 
Sacramento Association of Engineering and Environmental Geologists 

Sacramento AEG Virtual February Meeting: DWR's California Aqueduct Subsidence Program

Please join us on Tuesday, February 22 on Zoom! We will be hosting Dan Whisman, DWR CASP Program Manager; with contributions from Leroy Ellinghouse (DWR CASP Communications Manager) and Jeffrey Unruh (Lettis Consultants Intl., CASP Geologic Support) who will be giving a presentation on

DWR's California Aqueduct Subsidence Program.

DWR’s California Aqueduct Subsidence Program 

Dan Whisman, DWR CASP Program Manager; with contributions from Leroy Ellinghouse (DWR CASP Communications Manager) and Jeffrey Unruh (Lettis Consultants Intl., CASP Geologic Support)


The Department of Water Resources (DWR) built the State Water Project (SWP) - a network of canals, pipelines, reservoirs, and hydroelectric power facilities - in the 1960s/70s. It now delivers clean water to 27 million Californians, 750,000 acres of farmland, and businesses throughout California. The California Aqueduct (Aqueduct) serves as the main artery of the SWP and a linchpin of California’s water security.

 In 2006, the SWP’s San Luis Field Division began to see a reduction in flow capacity through a portion of the Aqueduct in the San Joaquin Valley. Subsidence had lowered portions of the Aqueduct and caused the concrete liner freeboard (the vertical distance between the water surface and the top of the concrete liner) to be reduced from its normal of 3 feet, to less than 1 foot of freeboard in some areas. Subsidence has also decreased the ability to store water in segments of the aqueduct, known as pools, which allows for operational flexibility and to more efficiently manage pumping at the Aqueduct’s pumping plants. While subsidence has reduced the amount of freeboard and flow capacity at specific locations, contracted deliveries have not been curtailed due to subsidence. The California Aqueduct Subsidence Program (CASP) was developed to address the adverse effects of subsidence on the Aqueduct in the San Joaquin Valley. This presentation will give an overview of the program, subsidence issues observed along the Aqueduct, and DWR’s current and planned actions to mitigate those effects.

Speaker Bios

Dan Whisman is a Principal Engineer in the Division of Engineering of the California Department of Water Resources (DWR), and the program manager for the California Aqueduct Subsidence Program. He has worked with DWR in various capacities since the mid-1990s, as consultant or employee. In addition to his private forensic engineering practice, Dan has served as the manager of DWR’s Construction Office and its Levee Repairs and Floodplain Management Office. He received his B.S. in Civil Engineering from California State University, Sacramento. He is a licensed Civil Engineer, Structural Engineer, and General Contractor in California.

Leroy Ellinghouse is a Supervising Right of Way Agent in the Real Estate Branch with the Division of Engineering of DWR, and is the Communications Manager for CASP.  He has spent his entire professional career with DWR starting in 1991 with the Division of Land and Right of Way, moving to the Division of Operations and Maintenance in 2000 and currently resides in the Division of Engineering. He has authored regulations that enable DWR to effectively manage its right of way and has assisted in multiple State Water Project acquisition projects including: DWR’s Coastal Aqueduct Pipeline Project, East Branch Extension, including Crafton Hills Reservoir and East Branch Extension Phase II.  In addition, he led the Roads Management Team during the Oroville Spillway Incident. Prior to working at DWR he worked as a student assistant for the Department of Transportation in Fresno, while attending Fresno State University.