Third Consequence: Drought/Surface Water Shortages Fourth Consequence: Decline of Groundwater & Underground Flows

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1 Third Consequence: Drought/Surface Water Shortages Fourth Consequence: Decline of Groundwater & Underground Flows Water Assembly March 21, 2015 J. Phillip King, P.E., Ph.D. Professor and Associate Department Head Department of Civil Engineering, NMSU Consultant Elephant Butte Irrigation District Image Corruptopolis

2 Interstate Water Sharing Agreement: The Rio Grande Compact Compact CO Compact NM NM Lower Rio Grande: TX surface water? NM Groundwater? Compact TX Texas Mexico Basemap from Hurd and Coonrod 2007

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4 Annual Allotment,

5 Release and Diversion in the Rio Grande Project,

6 GroundWater Level Data Continuous water levels Short- term variability Intermittent water levels Intermediate to long term variability Annual Water Levels Measured during the winter, assumed to be period of reduced water use Indicates recovery of aquifer Long term variability

7 March-July Runoff Forecasts by month at San Marcial, % Confidence interval

8 Otowi and San Marcial Gauges, 2014

9 Water Quality WL H4 SC

10 Water Quality WL H13 SC

11 Water Quality WL MES8R SC

12 Water Quality WL MES23R SC

13 Extensive vs. Intensive Irrigation Extensive Lower management/investment level Maximize acreage High unit application Low unit depletion Low unit production Intensive Higher management/investment level Focus on reduced acreage Reduced unit application High unit depletion High unit production

14 Drought/CC Cycle Multi-decadal wet period Vicious Circle Spiral of Death Positive Feedback System Increased water use Development Investment Decreased SW Increased Seepage Increased GW use Decreased GW recharge Decreased production etc Decreased SW Reduced SW supply Increased production profit Increased GW use WQ problems Increased investment Drought returns

15 Damping Effects in a Positive Feedback System Wet years Wells lose capacity as water table drops Groundwater degradation as salt water intrudes, accumulates in groundwater Land taken out of production Controls on M&I development Market effects on price of water New limitations forced by courts

16 Potential Impacts on Rio Grande, Project, Compact Increasingly arid climate not contemplated in design of Project, obligations in Compact Hydrologic effects of drought/aridity disproportionally affect downstream Compact magnifies downstream effects Changing hydrology of basin will lead to persistent shortage in Project Changing hydrology may lead to persistent Compact violations Groundwater depletion delays, masks effects Similar scenarios are playing out around the world

17 Ideas for a Binational Desalination Plant

18 The Booming Border Region Santa Teresa/San Geronimo Santa Teresa San Geronimo LPOE Historic Backwater Binational effort to develop trade, Land Port of Entry infrastructure Access to deep water ports in Long Beach, Houston, Mazatlán Development for 200 k platted in Santa Teresa Grande plans for San Geronimo Deep Upper/Middle/Lower Santa Fe aquifers Lots of brackish water, little fresh Development will come looking for fresh water 50,000,000 acre-feet of economically extractable (for M&I) brackish to saline water in the yellow zone

19 Flow, cfs Storm Water Capture Placitas: 197 AF Rincon: 955 AF Total: 1,152 AF Placitas Rincon 7/8 12:00 7/9 12:00 7/10 12:00 7/11 12:00 7/12 12:00 High intensity, generally monsoonal events downstream of Caballo Dam Historical strategy is to evacuate water downstream as quickly as possible Capture water in flood control dams, agricultural canals and drains Direct use, regulation to meet downstream demand, infiltration for aquifer recharge

20 Issues Flood control dams are inadequate for normal operations, not designed for storage Storing water increases likelihood of failure New operations may increase liability Poor watershed conditions result in steep hydrographs, high debris and sediment concentrations

21 Approach Modification of existing drainage facilities including new storage capacity and regulation structures Multi-objective (criteria) approach: Flood control and protection Increase usable water Habitat creation Water quality improvement Formal decision models to clearly identify: Criteria for design and operation Values, utility function to balance tradeoffs among criteria, risk behavior Sources and nature of uncertainty

22 Policy Implications Objective is not to keep all existing uses in place Status quo is not an option. We will reduce our water use; either we do it ourselves or Mother Nature and Adam Smith will do it for us New sources will provide additional water, but it is a pittance compared to the shift to a more arid climate We must figure out how to reduce our water use to minimize societal and cultural damage Responsive management and administration is a must Understanding dynamics and monitoring of system state are critical to adaptation