2007 Ground Water Summit


Monday, April 30, 2007
4:30 p.m. - 7:30 p.m.

Tuesday, May 1, 2007
9:30 a.m. - 1:30 p.m.

Tuesday, May 1, 2007
4:30 p.m. - 7:30 p.m.

Sources and Evolution of Waters at Dos Palmas Preserve and Vicinity, Salton Sea, California

Mathew A. Kelliher, PG, CHG, Water Replenishment District of South California and Barry Hibbs, Ph.D., California State University, Los Angeles

Abstract
Colorado River water has been delivered to the Lower Coachella Valley in Riverside County, California through both lined and unlined segments of the Coachella Branch Canal since 1949.  Flow from springs and wells located downgradient of an unlined portion of the Canal has increased significantly since its construction. Lining of the entire Canal is scheduled for completion in December 2006.  Samples were collected from several spring and well locations downgradient from Coachella Canal to assess their geochemical and isotopic signatures for comparison to Canal and native groundwater sources.  Analysis of stable isotopes identifies three distinct groups of water; one group consists of nearly pure Canal water with d18O ranging from -11.3 to -11.7 and d2H ranging from -84 to -95.  A second group consists of nearly pure native groundwater with d18O ranging from -7.3 to -8.7 and d2H ranging from -59.5 to -71.  A third group consists of various mixtures of Canal and native groundwater with d18O ranging from -8.7 to -11.1 and d2H ranging from -80 to -91.  Leakage from the Canal has created an extensive series of wetlands and wetland habitat that could be lost after Canal lining.  Continued monitoring of these locations should be done after lining of the Canal to determine the effect of reduced spring and well flow on the current wetland areas.

The 2007 Ground Water Summit