CC 2018-08-14_12a Annual Report 2017 NCMA PP PresentationNCMA 2017 Annual Report
Ag Representatives Meeting
Paul Sorensen
GSI Water Solutions, Inc.
June 15, 2018
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Presentation Overview
2017 Hydrology (Precipitation and Evapotranspiration)
2017 Water Demand
Groundwater Basin Conditions
Key Findings
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Santa Maria Groundwater Basin
Three management areas (NCMA, NMMA, SMVMA)
Mandated monitoring program and Annual Report
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Northern Cities Management Area
City of Arroyo Grande
City of Pismo Beach
City of Grover Beach
Oceano Community Services District
Private Users
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Hydrogeology
Average annual rainfall –
15.6 inches
Rainfall in 2017 – 18.9 inches
Only 3rd time since 2001 that rainfall has exceeded long-term average
Below average rainfall in
8 of 12 months
ET exceeded rainfall in all months except January and February
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Annual Precipitation 1950-2017
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NCMA Agricultural Land 2017
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Estimated Ag Pumpage - 2017
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NCMA Pumpage from SMGB - 2017
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NCMA Total Use - 2017
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Historical NCMA Production/Delivery
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Locations of Monitoring Wells
5 coastal well clusters
16 wells total
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Groundwater Levels Spring 2017
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Groundwater Levels Fall 2017
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Historical April Deep Well Index
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Key Findings
Total 2017 NCMA Water Use – 8,519 AF (8,108 AF in 2016)
Lopez Lake – 4,553 AF (2,610 AF in 2016)
State Water Project – 451 AF (1,907 AF in 2016)
Groundwater – 3,456 AF (3,511 AF in 2016)
Other Groundwater – 59 AF (79 AF in 2016)
Groundwater pumping is 36% of 9,500 AFY safe yield
Estimated increase of 1,500 AF of groundwater in storage (expected to be greater given rainfall year and relative lack of pumping)
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Why Aren’t Water Levels Higher?
Continued effects of drought, unequal distribution of rainfall events
Reduction of recharge from east due to overdraft on Mesa
Not because of overpumping in NCMA
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Threats
Continued overdraft on Mesa (currently 7,000 to 8,000 AFY)
Sea water intrusion
Potential increased groundwater demand in NCMA
Threat to Lopez Lake supply
Threat to SWP deliveries
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Questions?
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