New Mexico Universities Working Group
on Water Supply Vulnerabilities:
The Lower Rio Grande
Presented to the
Paso del Norte Watershed Council
Phil King
October 22, 2015
Background
• Funded by the NM State Legislature in FY 14 to:
• Assess the current state of water supply and demand
after years of severe drought;
• Put the current drought into long-term context with
reduced surface water, groundwater depletions, and
economic activity;
• Develop a list of vulnerabilities and promote policy
strategies to mitigate these vulnerabilities.
The Group
• Janie Chermak, UNM
• David Gutzler, UNM
• Peggy Johnson,
NMIMT NMBGMR
• Phil King, NMSU
• Lee Reynis, UNM BBER
• Gwen Aldrich, UNM
BBER
• Michael O’Donnell,
UNM BBER
Average Depth to Groundwater in the Mesilla Valley, 1946-1958
Peggy Johnson, NMT/NMBG 2015
Groundwater Elevation in the Mesilla Valley, 1946-2015
Peggy Johnson, NMT/NMBG 2015
Groundwater Elevation in the Mesilla Valley, 1995-2015
Data from Connie A. Woodhouse, 2012.
Forecasting Problems:
David Gutzler, UNM 2015
Total Private Sector Employment, 1951-2015
Indexed to 1951
17.0
16.0
15.0
14.0
13.0
12.0
11.0
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0
Las Cruces
NM
51
61
71
81
Source of data: US Bureau of Labor Statistics, Quarterly Census of Employment and Wages
91
01
11
Principal Vulnerabilities: 1
Extended, severe drought significantly affects both surface
water and groundwater supplies by disrupting the balance
between precipitation and evapotranspiration in the
hydrologic cycle. All credible projections of 21st century
climate call for continued warming in the decades to come.
Numerous assessments of groundwater vulnerability to a
warming climate project that groundwater resources will be
adversely affected by even small increases in temperature,
regardless of changes in rainfall. The most significant adverse
effects that severe drought and a warming climate have on
groundwater resources are: (1) reducing the availability and
distribution of groundwater recharge; (2) compounding
groundwater depletions with additional pumping; and (3)
intensifying groundwater declines that result in a permanent
loss of groundwater storage.
Principal Vulnerabilities: 2
Recent investments and developments in the Santa
Teresa, NM area will likely lead to additional
businesses (re)locating to the area, and thus to
additional population growth. The current water
supply is anticipated to meet the area’s needs for the
next decade only.
Principal Vulnerabilities: 3
Continuing drought will be increasingly detrimental
to agriculture. Various strategies and technologies
can be used to increase resiliency to drought,
although all require additional expenses that present
an additional financial burden, particularly difficult
for small farms.
Principal Vulnerabilities: 4
Economic development and growth that does not
consider the interactions and tradeoffs between
human activity and the physical realities of water
supply (and variability of supply) may result in
increasingly severe constraints in times of drought
that cannot easily be mitigated.
Recommendations: 1
• Consider the entire spread of seasonal streamflow outlooks rather than
just the median value, to explicitly account for the possibility of a
continuation of forecast overestimates of snowmelt runoff.
• Continue assessment of the principal social and economic vulnerabilities
associated with water shortages in the Lower Rio Grande, and update
these vulnerabilities as the 2015 water supply situation becomes
clearer.
• Initiate development of possible strategies for strengthening long-term
resiliency to water shortages by bringing supply and demand closer to
balance. Specifically, consider strategies that allow flexibility in times of
shortages that consider the physical and the economic impact of the
choices.
• Initiate development of possible strategies for addressing short-term
deficiencies in surface water supplies based on prudent use of
groundwater resources, and cooperate with legislators and water
managers in the LRG to develop effective, resilient water policy and
practices to be more responsive to short, medium, and long-term
fluctuations in available water supply.
Recommendations: 2
• Consider better integrating the management of groundwater and surface water
resources by, for example, optimizing the municipal-industrial use of
groundwater during severe drought to minimize impacts to surface water and
shallow aquifers.
• Investigate feasible means of reducing groundwater pumping and artificially
enhancing groundwater recharge in order to mitigate the depletion of
groundwater storage.
• Research and assessment of additional water sources should begin immediately.
Due to stress imparted upon the region’s water supplies by the ongoing
drought, it is unlikely that additional freshwaters will be available. Given the
availability of brackish water, a desalination plant is an option that should be
given serious consideration.
• Implement policies that will aid in the conversion of farmland from flood
irrigation to more efficient irrigation methods such as subsurface drip. Seek to
develop partnerships between farmers, Elephant Butte Irrigation District (EBID),
NRCS, the Bureau of Reclamation, and other relevant agencies to plan and fund
water conservation projects that address both delivery system efficiency and onfarm water conservation.