San Gabriel Valley Water Forum San Gabriel Valley Water Supply

1. San Gabriel Valley Water ForumSan Gabriel Valley Water Supply Presented by: Stetson Engineers Inc. April 17, 2014

2. 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

3. San Gabriel Valley Water Supply • Stetson Engineers Inc. • Engineer/Consultant to Sponsors of the Water Forum • Upper San Gabriel Valley Municipal Water District • San Gabriel Valley Municipal Water District • Main San Gabriel Basin Watermaster • Water Quality Authority

4. San Gabriel Valley Water SupplyGROUNDWATER BASINS WITHIN LOS ANGELES REGION Source: Regional Water Quality Control Board

5. 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

6. San Gabriel Valley Water Supply • Local water supply management • Groundwater levels • 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

7. San Gabriel Valley Water Supply

8. San Gabriel Valley Water SupplyRAINFALL AT PASADENA CITY HALL STATION 610B

9. 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

10. San Gabriel Valley Water SupplyPRODUCTION IN MAIN SAN GABRIEL BASIN

11. 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 acre-feet over past four years

12. 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

13. San Gabriel Valley Water SupplyBALDWIN PARK KEY WELL GROUNDWATER ELEVATION

14. 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

15. San Gabriel Valley Water SupplyFORECAST AT BALDWIN PARK KEY WELL

16. 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