Western Groundwater: A Status Report and a Look Ahead

Transcription

1 Western Groundwater: A Status Report and a Look Ahead Dr. Leonard F. Konikow Scientist Emeritus, U.S. Geological Survey Reston, VA University of Colorado Getches-Wilkinson Center for Natural Resources, Energy, and the Environment June 7, 2018

2 WATER SUPPLY FROM WELLS From: USGS Circular 1279 (2005) & USDA

3 WATER SUPPLY FROM WELLS Drilling a Water Well Los Angeles County production well (Photo: L. Metzger, USGS ) Large capacity industrial well at a paper mill, Georgia. (Photo by A.M. Cressler, USGS) Irrigation well, near La Junta, Colorado

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5 NATURAL/PREDEVELOPMENT CONDITIONS RECHARGE DISCHARGE

6 POST-DEVELOPMENT CONDITIONS Q (Wells) DD DS DR where Q =pumpage, DS = change in GW storage, DD = change in GW discharge, & DR = change in GW recharge

7 POST-DEVELOPMENT CONDITIONS Q (Wells) DD DS DR DS = GW STORAGE DEPLETION DD + DR = CAPTURE

8 % OF GW PUMPAGE Timing: Sources of Water to a Well 100 WATER FROM CAPTURE (increased recharge + decreased discharge) 50 WATER FROM GW STORAGE DEPLETION 0 PUMPING TIME Modified from Heath, 1983

9 Streamflow Depletion by Wells An extremely important issue affecting water and environmental management Streamflow depletion results from: Induced infiltration Reduced groundwater discharge (base flow) Similar effects on springs, lakes, ponds, wetlands, and coastal estuaries. Many legal ramifications

10 In the U.S., groundwater discharge represents 15-90% of total annual streamflow about 50% on average (Winter et al., 1998) Download free from:

11 56% of the streamflow in the UCRB originated as base flow, 2016

12 MEASURES OF GROUNDWATER DEPLETION: WATER-LEVEL DECLINE VS VOLUMETRIC DECREASE

13 AREAS & WELLS WITH WATER-LEVEL DECLINES > 40 FT SINCE PREDEVELOPMENT (>25 FT IN UNCONFINED AQUIFERS) From: USGS Circ (Reilly et al., 2008)

14 GROUNDWATER LEVEL, in FEET BELOW LAND SURFACE Water Level in Well, Las Vegas, NV 0 50 Well SOURCE: U.S. Geological Survey

15 GROUNDWATER LEVEL (ft BLS) Groundwater Level vs Population, Las Vegas

16 ANNUAL DISCHARGE (10 3 m 3 ) 14,000 10,000 6,000 2,000 0 Start of GW pumping (1913) YEAR Annual discharge from regional springs in Pahrump Valley, Nevada, Modified from USGS Prof. Paper 1711

17 MEASURES OF GROUNDWATER DEPLETION: WATER-LEVEL DECLINE VS VOLUMETRIC DECREASE

18 CUMULATIVE VOLUMETRIC GROUNDWATER DEPLETION ( ) in km 3 GROUNDWATER DEPLETION (km 3 ) From: Konikow (2013) U.S. Geol. Survey SIR

19 GROUNDWATER DEPLETION IN ARIZONA ( ) Source: from Konikow (2013); from Scanlon et al. (2015)

20 CHANGES IN GROUNDWATER LEVELS IN HIGH PLAINS AQUIFER (PREDEVELOPMENT-2015) VOLUME REMOVED FROM STORAGE 243 km 3 (by 2000) & 400 km 3 (by 2015) from: V.L. McGuire (2017); SIR

21 500 GROUNDWATER DEPLETION IN HIGH PLAINS AQUIFER ( ) DEPLETION VOLUME (KM 3 ) Source: from Konikow (2013); from McGuire (multiple reports)

22 Landsat 7 image showing center pivot irrigation patterns near Garden City, Kansas Center pivot irrigation system with drop nozzles in western Kansas, photograph by Lori Marintzer, U.S. Geological Survey. (USGS Fact-Sheet )

23 MAJOR PERENNIAL STREAMS IN KANSAS: 1961 & 2009 Streams regarded as perennial in 1961 but as nonperennial in 2009 Streams regarded as perennial in both 1961 and 2009

24 DEPLETION INTENSITY ( )

25 CENTRAL VALLEY AQUIFER SYSTEM, CALIFORNIA LAND SUBSIDENCE (mm) CUMULATIVE CHANGE IN GROUNDWATER STORAGE (km 3 ) DEPTH TO WATER (m) Groundwater Storage Change From: Faunt & Sneed (2015)

26 GROUNDWATER DEPLETION IN SNAKE RIVER PLAIN AQUIFER, IDAHO ( )

27 NONDIMENSIONAL RELATIONS PUMPAGE PUMPAGE = STORAGE DEPLETION DEPLETION + CAPTURE + CAPTURE DEPLETION VOLUME DEPLETION FRACTION = CUMULATIVE PUMPAGE CAPTURE FRACTION = 1- (DEPLETION FRACTION)

28 TOTAL U.S. GW DEPLETION ( ) = 15% of Q (85% of Q from CAPTURE)

29 DEPLETION FRACTION IN SELECTED U.S. AQUIFERS

30 CENTRAL VALLEY, CALIFORNIA: CUMULATIVE (---) vs ANNUAL FRACTIONS ( ) FRACTION Data from: Faunt et al. (2009) USGS Prof. Paper 1766

31 LONG-TERM GROUNDWATER DEPLETION IN THE U.S. 1,000 km 3 in km 3 in 2000

32 CUMULATIVE GLOBAL GW DEPLETION, ,530 km 3 in ,370 km 3 in 2000

33 National Academy of Sciences (2013) (2014) U.N. (2015)

34 Violent protest in Bolivia over government increases to the cost of water

35 TWO FACTORS CONTRIBUTING TO WATER STRESS: INCREASING GROUNDWATER DEPLETION CLIMATE CHANGE

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37 The future? GROWING POPULATION INCREASED DEMANDS FOR FOOD & WATER SUPPLY (DRIVING FORCE) CLIMATE & HYDROLOGIC SYSTEMS ARE CHANGING WE WILL NEED BOTH (1) IMPROVED WATER MANAGEMENT & (2) ADAPTATION TO CHANGE

38 CONCLUSIONS GW DEPLETION IS GROWING SUSTAINABILITY OF PRESENT GROUNDWATER USE IS AT RISK GROUNDWATER & SURFACE WATER ARE INTERCONNECTED ( A Single Resource )

39 ON AVERAGE: CONCLUSIONS MOST GW WITHDRAWALS BALANCED BY CAPTURE LESS BALANCED BY GW STORAGE DEPLETION

40 CONCLUSIONS GW PUMPING & DEPLETION CAN CAUSE DETRIMENTAL ENVIRONMENTAL EFFECTS INNOVATIVE WATER MANAGEMENT ACTIONS CAN HELP MITIGATE PROBLEMS

41 CONCLUSIONS WATER POLICY & LEGAL FRAMEWORK MAY NEED TO BE MODIFIED TO FACILITATE OPTIMAL WATER USE & SUSTINABILITY GOALS LAWS OF NATURE TAKE PRECEDENCE ECONOMICS HAVE STRONG INFLUENCE

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43 Upper Colorado River Basin From: Miller et al. (2017) (USGS SIR )

44 Colorado River Basin. Upper Basin outlined in red. From: USGS FS

45 2015