Coastal Seawater Intrusion Program Updatecemonterey.ucanr.edu/files/162222.pdf · TodayToday s’s...

Coastal Salinas ValleyCoastal Salinas ValleySeawater IntrusionProgram and Update

2013 Irrigation and Nutrient Management MeetingMonterey County Water Resources Agency

26 February 2013Page 1

Today’s PresentationToday s Presentation

How Seawater Intrusion (SWI) WorksHow Seawater Intrusion (SWI) WorksAgency Projects to Combat SWICoastal Monitoring ProgramCoastal Monitoring Program2011 SWI Front MapsQuestionsQuestions



Cross Section Near the Coast

180 Ft. Aquifer180 Ft. Aquifer

400 Ft. Aquifer400 Ft. Aquifer



Deep AquiferDeep Aquifer

Projects to Combat Seawater IntrusionjNacimiento Dam (1957) San Antonio Dam (1965)San Antonio 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 yearS li ll j (S ) (2010)Salinas Valley Water Project (SVWP) (2010)– Nacimiento Spillway Modification– Salinas River Diversion Facility (SRDF)– Salinas River Diversion Facility (SRDF)



Lake Nacimiento

Completed in 1957Completed in 1957Lake Capacity 377,900 AF



Lake San Antonio

Completed in 1965Lake Capacity 335,000 AF



CSIP & SVRP

SalinasSalinas

CastrovilleCastroville

Monterey

Completed 1997Average Delivery – 13,000 AF/Yr

Bay



Average Delivery 13,000 AF/Yr

Salinas Valley Water Project

• Nacimiento Spillway ModificationS li Ri Di i F ilit



• Salinas River Diversion Facility

Seawater Intrusion DataMonitoring

Ground Water Wells – Sampled annually during peak pumping– Sampled annually during peak pumping– 90 Agricultural wells sampled 2‐3 times17 Dedicated monitoring wells sampled– 17 Dedicated monitoring wells sampled

– Analyzed for General Minerals



Seawater Intrusion Data (cont.)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



Chloride & ConductivityTime Series Indicating Intrusion

/

Chloride > 360 mg/L2400

3000

1200

1500

m)

14S/02E‐34XXX

1200

1800

600

900

vity (uS/cm

ide (m

g/L)

Chloride 21 mg/L

0

600

1200

0

300

600

Cond

ucti

Chlori

00

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

2005

2007

2009

2011

2013

Chloride Conductivity



Chloride Conductivity

Cations Anionsmeq/kg

No Intrusion - 1982Cations Anionsmeq/kg

0 5 10510

Mg SO4

Stiff Di

Ca HCO3 + CO3

Na + K ClDiagramsEarly Intrusion - 2009

Cations Anionsmeq/kg

0 5 10510

M g SO 4M g SO 4

Ca HCO 3 + CO 3



Na + K C l

Piper Diagram Indicating Phase‐I Intrusion

Chloride > 360 mg/L

Chloride 21 mg/L



Chloride vs Na/Cl Molar RatioChloride vs. Na/Cl Molar Ratio14S/03E‐19XXX

Chloride > 360 mg/L250

300

L)

2

2.5

r)

150

200

oride (m

g/L

1.5

Ratio (m

ola

Chloride 21 mg/L

50

100

Chlo

0.5

1

Na/Cl R0.86

0

50

988

991

994

997

000

003

006

009

012

0



1 1 1 1 2 2 2 2 2

Seawater Intrusion Data (cont.)

L b R lt E l t d & U l d d i t WRAIMSLab Results are Evaluated & Uploaded into WRAIMS database annually

500 mg/L Contours are Developed from the Odd Year Data & Added to the Historic SWI MapsData & Added to the Historic SWI Maps



2011 Pressure 180‐Foot Aquifer500 mg/L Chloride Areasg/





Pressure 180‐Foot Aquifer Historical AdvancementHistorical Advancement

Estimated Acreage Overlying Seawater Intrusion Pressure 180-Foot Aquifer

19,817

21,619

24,01924,780

25,407

27,17527,60027,79128,142

20 000

25,000

30,000Seawater Intrusion Pressure 180-Foot Aquifer

7 672

11,645

16,221

19,817

10,000

15,000

20,000

Acr

eage

1,833

7,672

0

5,000

Cumulative Advance Source: MCWRAGraph Date: 08/27/12



ion Pressure 180-Foot AquiferPressure 180‐Foot Aquifer

27,175 27,60027,79128,142

Historical Advancement

19,817

25,40724,78024,019

21,619

11,645

16,221

1974

1977

1980

1983

1986

1989

1992

1995

1998

2001

2004

2007

2010

2013



Year

2011 Pressure 400‐Foot Aquifer500 mg/L Chloride Areas





Pressure 400‐Foot Aquifer

Estimated Acreage Overlying Seawater Intrusion Pressure 400 Foot Aquifer

Historical Advancement

10,50411,003

11,52311,88212,00412,097

12,573

12,000

15,000Seawater Intrusion Pressure 400-Foot Aquifer

7,521

8,3478,658

9,065

9,961

6,000

9,000

Acr

eage

22

3,717

3,000

220

Cumulative Advance Source: MCWRAGraph Date: 08/27/12



mated Acreage Overlying i P 400 F A if

Pressure 400‐Foot Aquifer rusion Pressure 400-Foot Aquifer

qHistorical Advancement

9 96110,504

11,00311,52311,88212,00412,097

12,573

7,521

9,0659,961

8,347 8,658

3,717

971

974

977

980

983

986

989

992

995

998

2001

2004

2007

2010

2013



197

197

197

198

198

198

198

199

199

199

200

200

200

20 20

SummarySummary

How Seawater Intrusion (SWI) WorksHow Seawater Intrusion (SWI) WorksAgency Projects to Combat SWICoastal Monitoring ProgramCoastal Monitoring Program2011 SWI Front Maps



ConclusionConclusion

Seawater Intrusion (2009 to 2011)– Rate of SWI continues to decrease– Advancement minimal, lobes are broadening– Complex mechanism for SWI persistsp p



“The water came in a thirty-year cycle. There would be five to six wetand wonderful years when there might be nineteen to twenty-five inchesand wonderful years when there might be nineteen to twenty five inchesof rain, and the land would shout with grass. Then would come six orseven pretty good years of twelve to sixteen inches of rain. And then the dry years would come …”y y

“And it never failed that during the dry years the people forgot about therich years, and during the wet years they lost all memory of the dry years.

l h ”It was always that way.”

John Steinbeck, East of Eden



Question ?Q


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