Planning Beyond the Supply/Demand Gap: Water Supply Vulnerabilities in New Mexico Presented by NM Universities Working Group on Drought

Transcription

1 Planning Beyond the Supply/Demand Gap: Water Supply Vulnerabilities in New Mexico Presented by NM Universities Working Group on Drought 1 Janie Chermak, David Gutzler, Peggy Johnson, J. Phillip King, Lee Reynis Drought, 1950s vs today: Climate, hydrology, agriculture and NM's economy (focusing on Lower Rio Grande) Short-term climate and streamflow forecast for 2015 Long-term hydrologic (im)balance, emphasizing groundwater Social and economic vulnerabilities to water shortages in the Lower Rio Grande Development of short-term and long-term strategies for improved resilience to water shortages NM Water Dialogue January 8, 2015

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3 Two Droughts, 50 Years Apart 2 Temperature is now much warmer than in the 1950s El Niño straight years of below-average precip out of 6 years of below-average precip (but snowpack has been worse)

4 Annual Release, AF Comparing Droughts: Caballo Reservoir Outflow 3 1,000, , , , , , , , , ,

5 New Mexico Reservoir Storage 31 Oct 2014 US Drought Monitor 30 Dec Despite abundant summer rains, most reservoirs contain belowaverage storage at the end of 2014 most notably, Elephant Butte CLIMAS (U Arizona) Southwest Climate Outlook November 2014

6 Winter 2015 Climate Outlook issued 20 Nov Temperature Precipitation Across NM: 40-50% chance of Above-avg precipitation El Niño to the rescue this winter? Historically, El Niño southwardshifted Pacific storm track SST anomalies Oct 5 Jan 5

7 More snow, please! Weak-moderate El Niño is happening But snowpack is poor, again SWE % of average Jan 6, 2015 SST anomalies Oct 5 Jan 5 Much-below-average snow water along the western and southern snowpack margins

8 kaf Forecast Probability 90% NRCS Streamflow Forecast Analysis 6 70% 50% 30% 10% Average RG@Otowi Mar-Jul Jan 1 Feb 1 Mar 1 Apr 1 May 1 Jun Temp Temp SWE SWE Precip Precip Jan Feb Mar Apr May Flow Forecast Evolution: Rio Otowi (naturalized) for Mar-Jul Jan forecast was a severe overestimate Forecast reduced thereafter as temp and precip anomalies persisted through the Spring months Observed flow far below average, but above late spring forecast, due to recovery in summer (spring flows were very low) Climate Data (Anomalies) Very warm & dry from March - May Snowpack drops below avg 1 Feb onward Shaleene Chavarria, UNM Angus Goodbody, NRCS

9 kaf Forecast Probability 90% NRCS Streamflow Forecast Analysis 6a 70% 50% 30% 10% Flow Forecast Evolution: Rio Otowi (naturalized) for Mar-Jul 2015 RG@Otowi 1 Jan 2014 Mar-Jul forecast issued 1 Jan 1 Jan 2015 (prelim) Worse than last year (!) Could El Niño moderate the extreme warm/dry Spring season conditions that we have experienced in recent years? Remember: Last year's flow Otowi turned out to be near the minimum of the 1 Jan forecast spread Climate Data (Anomalies) Snowpack is below average as of 1 Jan But there's still time for El Niño to shift the stormtrack southward ( more snow)... and keep melt season wetter and cooler

10 Groundwater Vulnerability During Drought New Mexico Water Dialogue 21 st Annual Statewide Meeting LEARNING TO LIVE WITH LESS WATER New Mexico Universities Working Group on Water Supply Vulnerabilities Peggy Johnson Principal Hydrogeologist New Mexico Bureau of Geology January 8, 2015 New Mexico Bureau of Geology & Mineral Resources, A Division of New Mexico Tech

11 Groundwater Systems A hydrologic balance between recharge, discharge and changes in aquifer storage Recharge occurs when Precipitation >>Evaporation Groundwater has provided a stable water reserve during short-term droughts recharges during wet cycles or with seasonal streamflow Warming climate will impact the P-ET balance and change the distribution of groundwater recharge and availability New Mexico Bureau of Geology & Mineral Resources

12 Groundwater Systems Under Warming Climate An increase global mean temperature by 1.0 C, regardless of rainfall, produces a cascade of negative impacts on groundwater Large increase in the evaporative demand (higher T, greater ET) Decrease in soil-water content Decrease in water infiltration below the root zone Reduced groundwater recharge Increased evaporative losses from shallow GW, streams, lakes Increased groundwater pumping to compensate for surface shortages New Mexico Bureau of Geology & Mineral Resources

13 Groundwater Depletion Rates of withdrawal exceed long-run average recharge = Groundwater Mining Increases groundwater vulnerability during drought High-frequency hydro-graphs in Mesilla Valley Shallow wells summer waterlevel high (recharge) Deep wells winter water-level high (resting wells) Seasonal fluctuations superposed on long-range declines Deep aquifers isolated from direct effects of climate change vulnerable to rapid depletion from drought-related pumping New Mexico Bureau of Geology & Mineral Resources

14 Groundwater Depletion New Mexico and Rio Grande Basin NMOSE water use reports, RGB serves 1.5 million Annual per capita depletion ~0.35 AF Lake Mead, 2013, holding 9 months of flow New Mexico Rio Grande Gravity Recovery and Climate Experiment (GRACE) Dec 2004 Nov 2013 Colorado River Basin Annual per capita depletion ~0.09 AF 77% of total water loss comes from groundwater Long-term reliance on GW combined with 14-yr drought drove rapid depletion Leads to further streamflow decline New Mexico Bureau of Geology & Mineral Resources

15 Factors Affecting Aquifer Vulnerability Aquifer type mountain bedrock vs. alluvial basin Aquifer storage thin aquifer, large alluvial basin, fractured, isolated compartment Aquifer recharge shallow 30m? m? vs. deep >300m Hydrogeologic setting determines how vulnerable or resilient ground water is to combined pressures of warming climate, drought and depletion New Mexico Bureau of Geology & Mineral Resources

16 Water Budgets During Drought Dynamic balance between inflow and outflow > Evaporative demand < Recharge >> Pumping Inflows decrease Outflows increase Groundwater Vulnerabilities Shallow GW levels, streams, wetlands, springs Deep GW subject to increased pumping, which compounds water-level decline and long-term depletion New Mexico Bureau of Geology & Mineral Resources

17 1950s Drought vs. Today: NM Agriculture Response to the 1950 s drought was based on the opportunities available and the constraints Response to the current drought are and will be based on the opportunities available and the constraints Opportunities and constraints vary across the state The opportunities and the constraints of the 1950s are not the opportunities and constraints of today.

18 1954 FARM SIZE 2007 STATE DONA ANA CO

19 OPERATIONS WITH LIVESTOCK STATE of NEW MEXICO: NUMBER OF OPERATIONS WITH ANIMALS DONA ANA CO: NUMBER OF OPERATIONS WITH ANIMALS

20 NUMBER OF FARMS BY CROP TYPE STATE of NEW MEXICO: NUMBER OF FARMS BY CROP DONA ANA CO: NUMBER OF FARMS BY CROP

21 NEW MEXICO AGRICULTURE Agriculture today significantly different from the 1950 s Choices made in the 1950 s to mitigate impact of drought are not all available today Crop changes may constrain management choices Farm sizes can impact management choices Agricultural market have changed Management strategies results in tradeoffs

22 Water Demand in New Mexico s Lower Rio Grande 90.11% 6.81% 1.27% 0.76% 0.53% 0.49% 0.03% Irrigated Agriculture Public Water Systems Commercial Livestock Domestic wells Power Industrial/Mining Irrigated agriculture by far the largest, all of Rio Grande Project surface water diversion in New Mexico No M&I use of surface water (yet) 2004 LRG Regional Water Plan

23 The Economy and Drought, the 1950s and Today, NM and Las Cruces Preliminary Results and Research under State Appropriation Dr. Lee A. Reynis UNM Burueau of Business and Economic Research

24 New Mexico Farm Sector New Mexico Farm Income as a % of Total Income 35.0% 30.0% 25.0% 20.0% 15.0% 10.0% 5.0% 0.0% Source of Data: US Bureau of Economic Analysis

25 The 1950 s Drought and the Economy 160, , , ,000 80,000 60,000 40,000 20,000 New Mexico Farm Income ($000s) Source of Data: US Bureau of Economic Analysis

26 The 1950 s Drought and the Economy 80% 70% 60% 50% 40% Population Growth (%) by Decade Dona Ana County and New Mexico : Second Highest Percentage Growth on Record New Mexico Dona Ana 30% 20% 10% 0% Source: US Bureau of the Census, Decennial Census,

27 The 1950 s Drought and the Economy Agricultural Workforce Shrinks, Rest of the Economy Takes Off New Mexico Change Agricultural Labor Force 39,488 22,568 (16,920) -43% Employed in Agriculture 37,895 20,514 (17,381) -46% Non Ag Labor Force 178, , ,553 58% Total Non-Ag Employed 168, ,390 98,821 59% Source: Decennal Census 1960

28 18 The Economy Since the 1950 s Total Private Sector Employment Indexed to 1951 Las Cruces MSA and New Mexico Las Cruces NM Source: Quarterly Census of Employment and Wages

29 800,000 New Mexico, Composition of Private Sector Wage and Salary Employment 1951 to , , , , , ,000 Other Srvices Accom & Food Serv FIRE Trade TCU Manufacturing Construction Ag & Mining 100, Source: Quarterly Census of Employment and Wages

30 55,000 50,000 Las Cruces MSA, Composition of Private Sector Wage and Salary Covered Employment, 1951 to ,000 40,000 35,000 30,000 25,000 20,000 15,000 10,000 5, Other Services Accom & Food Serv FIRE Trade TCU Manufacturing Construction Ag & Mining Almost all agricultural but note unemploy coverage effectively extended to some farm workers (large farms) in 70 s. Source: Quarterly Census of Employment and Wages

31 Recent Climate Variability/Drought and the Economy New Mexico, Las Cruces MSA and US Employment Monthly, Seasonally Adjusted, Each Indexed to 2008 Peak Source: US BLS CES New Mexico Las Cruces US UNM Bureau of Business and Economic Research

32 Current Drought and the Economy Agricultural Workforce Grows in Both NM and Dona Ana Co. NM Non-Ag Shrinks; Dona Ana Co. Grows. Water use up sharply Change New Mexico Agricultural Employment 28,946 32,026 3, % Non Ag Employment 1,078,110 1,042,512 (35,598) -3.3% Dona Ana County Agricultural Employment 2,963 3, % Non Ag Employment 88,626 90,197 1, % Source: US Bureau of Economic Analysis

33 Current Drought and the Economy At least in Dona Ana County, agricultural activity supported by very large groundwater diversions since Table provided by Adrienne Widmer, Las Cruces Utilities