Transcript San Gabriel Valley Water Forum San Gabriel Valley Water Supply

SAN GABRIEL VALLEY WATER FORUM
SAN GABRIEL VALLEY WATER SUPPLY
Presented by:
Stetson Engineers Inc.
April 17, 2014
SAN GABRIEL VALLEY WATER SUPPLY
• Location of Main San Gabriel Basin
• Local water supply conditions
• Groundwater level
• Rainfall
• Historical water use
• Imported water supply conditions
• Treated imported water
• Untreated imported water
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SAN GABRIEL VALLEY WATER SUPPLY
• Stetson Engineers Inc.
• Engineer/Consultant to Sponsors of the Water Forum
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Upper San Gabriel Valley Municipal Water District
San Gabriel Valley Municipal Water District
Main San Gabriel Basin Watermaster
Water Quality Authority
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SAN GABRIEL VALLEY WATER SUPPLY
GROUNDWATER BASINS WITHIN LOS ANGELES REGION
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Source: Regional Water Quality Control Board
SAN GABRIEL VALLEY WATER SUPPLY
• Local Water Supply Overview
• Groundwater levels are approaching a historic low
• Third year of below average rainfall
• Pre-delivery of untreated imported water; sufficient to satisfy two
future years of Replacement Water requirements
• Groundwater levels may not recover in near-term without
significant annual rainfall
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SAN GABRIEL VALLEY WATER SUPPLY
• Local water supply management
• Groundwater levels
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Based on measurement at “Baldwin Park Key Well”
Basin generally managed between elevation of 200 feet and 250 feet
Measured elevation as of April 11, 2014 about 194 feet
Historical high: 325 feet in 1944
Historical low: 189 feet in 2009
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SAN GABRIEL VALLEY WATER SUPPLY
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SAN GABRIEL VALLEY WATER SUPPLY
RAINFALL AT PASADENA CITY HALL STATION 610B
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SAN GABRIEL VALLEY WATER SUPPLY
• Historical water use
• Generally ranged between 240,000 acre-feet to 260,000 acre-feet
over past 10 years
• Decreased production between 2008 and 2012 as a result of
economy/conservation efforts
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SAN GABRIEL VALLEY WATER SUPPLY
PRODUCTION IN MAIN SAN GABRIEL BASIN
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SAN GABRIEL VALLEY WATER SUPPLY
• Imported water supply – State Water Project/Colorado River
• Treated water - MWD
• Emphasis on maximizing groundwater production to reduce treated
imported water demand
• Treated imported water demand has averaged about 12,000 acrefeet over past four years
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SAN GABRIEL VALLEY WATER SUPPLY
• Imported water supply (continued)
• Untreated water provided by MWD and SGVMWD (SWP
contractor)
• Delivered to San Gabriel Basin as Replacement Water and Cyclic
Storage water (pre-delivery)
• Cyclic Storage
• Pre-delivery of Replacement Water
• Management practice to deliver available imported water supplies to
off-set future Replacement Water demand when imported water
supplies may not be available
• Water currently in Cyclic Storage could address about two years of
Replacement Water demands
• Water in Cyclic Storage raises measured water level at Baldwin Park
Key Well
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SAN GABRIEL VALLEY WATER SUPPLY
BALDWIN PARK KEY WELL GROUNDWATER ELEVATION
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SAN GABRIEL VALLEY WATER SUPPLY
• Forecasted water levels at Baldwin Park Key Well
• Three forecasted rainfall scenarios (Fiscal years 2014-15 and
2015-16)
• Wet/average
• Average/average
• Dry/average
• No significant increase in water levels unless there is significant
annual rainfall
• Long-range forecast suggests 2014-15 may be an “El Niño” year
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SAN GABRIEL VALLEY WATER SUPPLY
FORECAST AT BALDWIN PARK KEY WELL
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SAN GABRIEL VALLEY WATER SUPPLY
• Summary
• Groundwater levels are approaching a historic low
• Third year of below average rainfall
• Pre-delivery of untreated imported water; sufficient to satisfy two
future years of Replacement Water requirements
• Groundwater levels may not recover in near-term without
significant annual rainfall
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