San Gabriel Valley From Stormwater to Supply Presented by Tony Zampiello, Executive Officer Main San Gabriel Basin Watermaster February 16, 2016

Raymond Basin San Gabriel Basin Six Basins Chino Basin & “PIPELINE STUDY” San Gabriel Basin Six Basins Proposed SGVMWD Pipeline Chino Basin

4/27/2017 Primary Water Supply Pumping is sustained by local runoff and supplemented with imported water Up to 90% from local supply ~ 250,000 AF/YR total 167 square-mile Basin surface area About 200 wells and several surface diversions San Gabriel River replenishes groundwater basin “Imported” water (Sacramento Delta) supplements local supplies, during normal and dry periods

Appropriation of Flood Waters Since 1934, the San Gabriel Valley Protective Association has been the appropriator of flood waters on the San Gabriel River. Licenses for over 300,000 AF. (Salvage of flood flows.) Association had no facilities for spreading December 7, 1937, entered into a contract with Los Angeles County Flood Control District to spread

Groundwater Recharge (LA County) Average recharge is 280,000 acre-feet of water per year Enough water to serve over 2.2 million people each year Over 1,000,000 acre-feet of water were recharged during the 2010 and 2011 water-years The value of this water is more than $550 million

How Water Reaches the Aquifer The Flood Control District, created in 1915 by State legislation, has a responsibility to manage stormwater runoff and other waters for beneficial and useful purposes Operates and Maintains: 26 groundwater recharge facilities (spreading grounds) 14 dams 16 rubber dams 524 miles of channels 2,800 miles of tributary storm drains

Key Facilities on the River San Gabriel Dam Morris Dam San Gabriel Canyon Spreading Grounds Santa Fe Spreading Grounds Santa Fe Dam (Army Corps of Engineers) Whittier Narrows Dam (Army Corps of Engineers)

Optimizing Large-Scale Storm Water Capture and Groundwater Recharge Increase and Improve: Storage capacity Intake capacity Percolation rate Prepare for: Long periods of stormwater runoff in wet years Opportunities to increase recharge of recycled water Opportunities to replenish the aquifers with imported water Efficiency Recently: 99% of San Gabriel River stormwater is captured

Enhance Stormwater Capture Projects Coordination with County of Los Angeles Flood Control Identified six (6) primary new stormwater capture projects Walnut Creek Spreading Basin Peck Road Spreading Basin Olive Pit Buena Vista Spreading Basin San Gabriel Canyon Spreading Grounds Miller Pit Potential 15,000 AFY of additional “new water” captured from new projects Four (4) projects have been implemented thus far Buena Vista Spreading Basin (completed) San Gabriel Canyon Spreading Grounds (completed) Walnut Creek Spreading Basin (under design) Peck Road Spreading Basin (under design)

Local Replenishment Challenges Long-Term Imported Supply Reliability Sediment Management Environmental Balance/Climate Change Flood Management Meeting Future Demands

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