Coastal Salinas Valley Seawater Intrusion Program and Update Page 1
Today s Presentation How Seawater Intrusion (SWI) Works Agency Projects to Combat SWI Coastal Monitoring Program 2011 SWI Front Maps Questions Page 2
Cross Section Near the Coast 180 Ft. Aquifer 400 Ft. Aquifer Page 3 Deep Aquifer
Projects to Combat Seawater Intrusion Nacimiento Dam (1957) SanAntonio Dam (1965) Castroville Seawater Intrusion Project (CSIP) & SVRP (1997) Recycled water is delivered to intruded areas to reduce ground water pumping Water delivered averages 13,000 acre feet per year Sli Salinas Valley Water Project (SVWP) (2010) Nacimiento Spillway Modification SalinasRiverDiversion Facility (SRDF) Page 4
Lake Nacimiento Completed in 1957 Lake Capacity 377,900 AF Page 5
Lake San Antonio Completed in 1965 Lake Capacity 335,000 AF Page 6
CSIP & SVRP Salinas Castroville Monterey Bay Completed 1997 Average Delivery 13,000AF/Yr Page 7
Salinas Valley Water Project Nacimiento Spillway Modification Sli Salinas River Diversion i Facility Page 8
Seawater Intrusion Data Monitoring Ground Water Wells Sampled annually during peak pumping 90 Agricultural wells sampled 2 3 times 17 Dedicated monitoring wells sampled Analyzed for General Minerals Page 9
Seawater Intrusion Data (cont.) Data Evaluation Historical Chloride & Conductivity Trends Stiff and Piper Diagrams Anion/ Cation Shifts Data Development Process Water quality Well construction Well pumping Ground water level contours Page 10
Chloride & Conductivity Time Series Indicating Intrusion Chlori ide (mg/l) 1500 1200 900 600 300 14S/02E 34XXX Chloride > 360 mg/l Chloride 21 mg/l 3000 2400 1800 1200 600 vity (us/cm m) Conducti 0 0 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011 2013 Chloride Conductivity Page 11
No Intrusion - 1982 Cations meq/kg Anions 10 5 0 5 10 Mg SO 4 Stiff Ca HCO 3 + CO 3 Diagrams Na + K Cl Early Intrusion - 2009 Cations meq/kg Anions 10 5 0 5 10 Mg SO 4 Ca HCO 3 + CO 3 Na + K Cl Page 12
Piper Diagram Indicating Phase I Intrusion Chloride > 360 mg/l Chloride 21 mg/l Page 13
Chloride vs. Na/Cl Molar Ratio 300 14S/03E 19XXX 2.5 Chlo oride (mg/l L) 250 200 150 100 Chloride 21 mg/l Chloride > 360 mg/l 0.86 2 1.5 1 r) Na/Cl Ratio (mola 50 0.5 0 0 1 1 1 1 2 2 2 2 2 988 991 994 997 000 003 006 009 012 Page 14
Seawater Intrusion Data (cont.) LbR Lab Results are Evaluated d& Uploaded dinto WRAIMS database annually 500 mg/l Contours are Developed from the Odd Year Data & Added to the Historic SWI Maps Page 15
2011 Pressure 180 Foot Aquifer 500 mg/l Chloride Areas Page 16
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Pressure 180 Foot Aquifer Historical Advancement 30,000 25,000 20,000000 Estimated Acreage Overlying Seawater Intrusion Pressure 180-Foot Aquifer 19,817 21,619 24,019 24,78025,407 27,175 27,600 27,791 28,142 Acreage 15,000 10,000 7672 7,672 11,645 16,221 5,000 1,833 0 Cumulative Advance Source: MCWRA Graph Date: 08/27/12 Page 18
Pressure 180 Foot Aquifer ion Pressure 180-Foot Aquifer Historical Advancement 24,780 24,019 27,175 27,60027,79128,142 25,407 19,8 17 21,619 16,221 11,6 4 5 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004 2007 2010 2013 Year Page 19
2011 Pressure 400 Foot Aquifer 500 mg/l Chloride Areas Page 20
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Pressure 400 Foot Aquifer Historical Advancement 15,000 Estimated Acreage Overlying SeawaterIntrusion Pressure 400-Foot FootAquifer 12,000 9,961 12,573 11,523 11,88212,004 12,097 11,003 10,504 Acreage 9,000 6,000 7,521 8,347 9,065 8,658 3,717 3,000 0 22 Cumulative Advance Source: MCWRA Graph Date: 08/27/12 Page 22
Pressure 400 Foot Aquifer mated Acreage Overlying rusion Pressure 400-Foot Aquifer Historical Advancement 7,521 8,347 8,658 9,065 10,50 411,003 9,961961 12,573 11,52 3 11,8 8 2 12,0 0 4 12,097 3,717 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004 2007 2010 2013 Page 23
Summary How Seawater Intrusion (SWI) Works Agency Projects to Combat SWI Coastal Monitoring Program 2011 SWI Front Maps Page 24
Conclusion Seawater Intrusion (2009 to 2011) Rate of SWI continues to decrease Advancement minimal, lobes are broadening Complex mechanism for SWI persists Page 25
The water came in a thirty-year cycle. There would be five to six wet and wonderful years when there might be nineteen to twenty-five inches of rain, and the land would shout with grass. Then would come six or seven pretty good years of twelve to sixteen inches of rain. And then the dry yyears would come And it never failed that during the dry years the people forgot about the rich years, and during the wet years they lost all memory of the dry years. It was always that way. John Steinbeck, East of Eden Page 26
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