Drought and California

Transcription

1 Drought and California Jay Lund Director, Center for Watershed Sciences Professor, Civil and Environmental Engineering University of California, Davis CaliforniaWaterBlog.com

2 What people know

3 Main Points 1) 4 th year of drought, so far similar to droughts seen 1-2 times per generation 2) California is doing amazingly well, given the magnitude of the drought 3) Stay between complacency and panic 4) Integrated portfolios are the future 5) High value crop production should be less affected 6) Droughts and floods remind us to change, and prepare. 3!

4 Water and People in California 4!

5 Most annual rainfall variability in US Annual coefficient of variation! SOURCE: Michael Dettinger, Climate Change, Atmospheric Rivers, and Floods in California A Multimodel Analysis of Storm Frequency and Magnitude Changes. Journal of the American Water Resources Association 47(3): ! NOTES: Dots represent the coefficient of variation of total annual precipitation at weather stations for , Larger values have greater year-to-year variability.!

6 Drought in California 1) Large agricultural water use (80% of human use) - 9 million irrigated acres, $45 billion/yr 2) $2 trillion economy 3) Native ecosystems fish and birds 4) Major changes in habitats, flows, species 5) Droughts lead to change 6!

7 Droughts test, and spur progress 1. Water needs are always changing 2. Major water policy changes require droughts, floods, or lawsuits benefits of drought 3. Every generation requires a threatening flood and a threatening drought We ve got one.

8 Sacramento Valley Precipitation 2014:! 8 th driest in 106 years! 8!

9 San Joaquin Valley Precipitation 2015:! 3rd driest in 106 years! 9!

10 ! Sierra Snowpack A warm drought! Lowest snowpack on record! 10!

11 Reservoir levels 11!

12 12! 2015 Water Shortage & Changes in Groundwater! 2015 Water use changes (MAF) Region Surface Net Delivery Water Groundwater Shortage Sacramento San Joaquin Tulare Central Coast and So. Cal Total

13 2015 Estimated Agricultural Drought Impacts! Description Impact Base year levels Percent change Surface water shortage (million acre-ft) % Groundwater replacement (million acre-ft) % Net water shortage (million acre-ft) % Drought-related idle land (acres) 540, million* 45% Crop revenue losses ($) $900 million $35 billion 2.6% Dairy and livestock revenue losses ($) $350 million $12.4 billion 2.8% Costs of additional pumping ($) $590 million $780 million 75.5% Direct costs ($) $1.8 billion NA NA Total economic impact ($) $2.7 billion NA NA Direct job losses (farm seasonal) 10, ,000 # 5.1% Total job losses 21,000 NA NA * NASA-ARC estimate of normal Central Valley idle land. # Total agriculture employment is about 412,000, of which 200,000 is farm production. 13!

14 Cumulative Jobs and Revenues! 100%! 90%! 80%! 70%! 60%! 50%! 40%! 30%! 20%! 10%! 0%! Vegetables,! Horticulture & Non-Tree Fruits! Fresh Tomato + Cucurbits! Subtropical Fruits! Vines! Deciduous (Orchards)! Onion + Garlic! Almonds and Pistachios! Processing Tomato! Other Field, Grain, and Feed Crops! Cumulative Jobs! Cumulative Revenues! 0! 2000! 4000! 6000! 8000! 10000! Cumulative Irrigated Crop Area (Acres)!

15 Cities and suburbs So far Investments paid off Regional cooperation Conservation working Continued drought Supplies more constrained Pricing restrictions (Prop 218) and affordability issues Some challenges with conservation mandate But economic impacts likely to remain small 15!

16 16! Rural communities So far 2,000+ dry domestic wells, 100+ small systems in trouble Strong emergency response But time lags still too long Continued drought Increase in dry wells Worsening air quality Economic hardship

17 Ecosystem and drought 18 fish at risk of extinction Need strategic flows, conservation hatcheries High waterbird mortality Need for strategic wetland watering Severe wildfire risk, with some permanent losses of conifer forests Little drought preparation 17!

18 Folsom Water Storage - Limited supply - Local & regional demands - Flood storage - Fish 18!

19 American R. Basin Supplies From: Mavensnotebook.com 19!

20 Drought Sac Metro Area Surprise! Sacramento Area is vulnerable to drought! 1) Cities hit by Folsom and Governor s orders 2) Shallow domestic wells 3) Native ecosystems fish and birds 4) Lost hydropower 5) Farming not too badly affected 6) Lost recreational skiing and rafting 20!

21 What to do? 1) Intertie urban surface supplies 2) Better manage groundwater 3) Reduce long-term water use 4) Improve environmental management 5) Prepare for less snow! 21!

22 Supply Portfolio-based Management Reoperation Reservoirs Conveyance Conjunctive use Expand conveyance & storage Urban reuse New water treatment Wastewater reuse Ocean Desalination Contaminated aquifers Stormwater capture Demand and Allocation Agricultural water use efficiencies and reductions Urban water use efficiencies and reductions Ecosystem demand management Recreation water use efficiencies Incentive policies Pricing Markets Subsidies, taxes Source protection! Education 22!

23 Innovations from this drought? 1. Groundwater management 2. Better water accounting 3. Better water markets 4. Lower targets for urban water use ripple effects for conservation, finance, planning 5. Higher agricultural water prices and less agricultural water use 6. Better state agency coordination? 7. Others? 23!

24 Droughts test water systems! 1. Water systems and the societies they serve are always changing. 2. Droughts bring attention to needs for change 3. This drought is helping California improve water management - groundwater 4. Every generation needs at least a threatening drought, and a threatening flood 24!

25 Conclusions 1) 4 th year of drought, so far similar to droughts seen 1-2 times per generation 2) California is doing amazingly well, given the magnitude of the drought 3) Stay between complacency and panic 4) Integrated portfolios are the future 5) Sacramento region is vulnerable to drought 6) Droughts and floods remind us to change, and prepare. 25!

26 Suggested Readings Hanak et al. (2011) Managing California s Water, PPIC.org Hanak et al. (2010) Myths of California Water, PPIC.org Hundley (1992), The Great Thirst, UC Press. Kelley (1989), Battling the Inland Sea, UC Press. Lund et al. (2010) Comparing Futures for the Sacramento San Joaquin Delta, UC Press Pisani (1983), From Family Farms to Agribusiness, UC Press Mavensnotebook.com CaliforniaWaterBlog.com

27 Will next year be dry? (from historical data, ) Probability next year Sacramento Valley San Joaquin Valley Next Year Historical Critical now Historical Critical now Critical Dry Below Normal C,D C,D, BN AN, W !

28 Streamflow and El Nino Sac. River Annual Runoff, maf! ENSO Index! 28!

29 El Nino and drought Annual Runoff, maf! ENSO Index! 29!

30 Resistance is Futile 1) Flooding in parts of the Delta 2) Reduced Delta diversions 3) Less irrigated land in the southern Central Valley 4) Less urban water use, more reuse & storm capture 5) Some native species unsustainable in the wild 6) Funding solutions mostly local and regional 7) State s leverage is mostly regulatory, not funding 8) Nitrate groundwater contamination is inevitable 9) Groundwater will be managed more tightly 10) The Salton Sink will be largely restored We cannot drought-proof, but we can manage better.