California s Sustainable GW Management Act and the Orange County Groundwater Basin

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1 California s Sustainable GW Management Act and the Orange County Groundwater Basin Roy Herndon Orange County Water District NWRI Clarke Prize Conference, Huntington Beach, CA

2 Gov. Brown signed the SGMA into law in Sept High- and medium-priority basins must: Accept or revise basin boundaries by Jan 2017 Establish GW Sustainability Agencies (GSAs) and GW Sustainability Plans by Jan 2020 or 2022 Achieve sustainability goal by

3 The forces for sustainable GW management in California were growing for years. Only western state without groundwater pumping regulations Lack of groundwater production and water level monitoring & reporting Depletion of Central Valley aquifers Land subsidence Seawater intrusion Impacts accelerated by Delta surface water reductions and drought 3

4 Central Valley GW depletion since 1984 exceeds the combined volume of Lakes Mead and Powell. ~60 MAF 4

5 Groundwater storage depletion has also led to land subsidence exceeding 1 ft/yr. 5

6 SGMA requires each basin to develop a Groundwater Sustainability Plan (GSP). A set of measures that will allow a basin to be operated within its sustainable yield, i.e., without causing an undesirable result such as: Chronic lowering of GW levels Reduction in storage Seawater intrusion Degraded water quality Land subsidence Impacts to surface water 6

7 GW Sustainability Plan Contents: Physical description of basin aquifer(s) Map of basin area and overlying GSAs Historical data GW levels, quality, subsidence, and GW-SW interaction Historical and projected water demands and supplies Map of existing and potential recharge areas and measurable objectives and 5-year interim milestones to achieve sustainability goal within 20 years. 7

8 While achieving sustainability will be difficult for many agriculturally-dominant basins, OCWD s longstanding basin management program essentially mirrors SGMA s requirements. 8

9 Groundwater is pumped from 200 wells and supplies 70% of total water demand for 2.4 million people. L.A. County $150 Million/year economic benefit relative to Imported Water 9

10 The basin is composed of three major aquifer systems. Huntington Beach 0 Drinking Water Wells Anaheim/Orange Recharge 1,000 2,000 3,000 NON-WATERBEARING FORMATION 0 miles

11 Acre-feet per Year (x 1,000) Groundwater production has more than doubled in last 60 years - sustainably Groundwater Production 0

12 OCWD s recharge operations and seawater barriers replenish and protect the basin.

13 Santa Ana River base and storm flows provide about 1/3 of the basin s recharge supply. Orange County Groundwater Basin Santa Ana River Watershed (nearly 3,000 sq. mi.)

14 Flow (1,000s of AF) Base flow and waste water discharges have substantially decreased since Wastewater Discharge Base Flow

15 GWRS has more than replaced the reduced Santa Ana River base flows. Natural Recharge 60,000 GWRS Recycled Water 103,000 SAR Base Flow 65,000 Storm Flow Imported Water 50,000 50,000 GW Basin Recharge Sources (AFY)

16 Operating Range (500,000 acre-feet) Basin storage is maintained within an established operating range to prevent adverse impacts. Basin Full Drought Periods

17 OCWD calculates the change in groundwater storage by measuring water levels in hundreds of monitoring wells. Single-depth monitoring well Multi-depth monitoring well

18 Principal Aquifer Water Level Change June 2013 to June

19 OCWD also uses groundwater models to evaluate the effects of potential basin operational scenarios. Increased Recharge Increased Pumping

20 Additional OCWD Programs Storm water conservation Water quality improvement 20

21 SGMA has raised the bar for basin management throughout the state. OCWD is well positioned Other basins face major challenges (tech, $, institut) Investments in data collection and analysis will: improve understanding of sustainable yield demonstrate if sustainability plans are working and how to fix them if they re not 21

22 End of Presentation 22