Historical Water Management in the Lower Rio Grande

Lower Rio Grande Water Users Organization

August 19, 2005J. Phillip King, P.E., Ph.D.

The Rio Grande Compact of 1938

• Researched and negotiated among Colorado, New Mexico, and Texas between 1925 and 1938

• Explicitly divided the surface water of the Rio Grande among the states, and providing for delivery to Mexico

• Sliding scale dependent on supply• Capped depletion in upstream states• Accounting rules and obligations allow flexibility

within each state

Compact NM

Compact TX

Compact Geography

Otowi

The Rio Grande Project• Water rights appropriated January 23, 1906• 90,640 water-righted acres in Elephant Butte

Irrigation District (EBID) in New Mexico• 69,010 water-righted acres in El Paso County

Water Improvement District No. 1 (EPCWID) in Texas

• 60,000 acre-feet of water for the Republic of Mexico by the Treaty of 1906

• Operated as a single irrigation system by Bureau of Reclamation

Project History in a Nutshell

0

200

400

600

800

1,000

1,200

1,400

1,600

1,800

2,000

1915 1925 1935 1945 1955 1965 1975 1985 1995 2005

Th

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Re

lea

se

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m E

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Bu

tte

, A

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1915-1937Start-up

1938-1950The

Roaring'40s

1951-1978Drought I

1979-2002The Wet

Years

20

03

-20

05

Dro

ug

ht

II

Compact Districts

Project Terminology

• Release – Flow of water from Caballo Dam• Diversion – Removal of water at Project

structures – Percha, Leasburg, Mesilla, American, International Dams

• Delivery – Flow from District canal to farm or non-agricultural use

• Return Flow – Drains, operational spills, storm flows, WWTP discharge

• River Efficiency – Diversion/Release

Current Project Allocation Procedure

• Usable water in storage determined

• Total diversion determined based on actual river efficiency

• Mexico allocation by formula

• Remaining diversion split between EBID (57 %) and EPCWID (43 %)

D2 – River Efficiency Relationship

0

200

400

600

800

1,000

1,200

0 200 400 600 800 1,000 1,200 1,400

Th

ou

sa

nd

s

ThousandsRelease from Caballo, AF

Pro

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t D

ive

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AF

38-5051-7879-0203-0405D2

District HydrologyCaballo

ConveyanceSystem

IrrigatedLand

Groundwater

DrainFlows

Atm

osph

ere

SeepageExfiltration

Pum

ping

Return

Diversion

Bypass (spill)Delivery

Deep Percolation

StormFlow

Bypass (spill)

Seepage

Release

Rio G

rande

M&IUsers

PumpingDeep Perc.

Discharges

Imported WaterExported Water

Non-irrigatedLand

Rio Grande at El Paso

Pum

ping

Dee

p P

erco

lati

on

ETPrecip

ETPrecip

Drainage

ET Precip

StormFlow

Storm

Storm

The LRG Regional Water Plan

• Prepared by the LRGWUO• Recognizes the hydrologic connection between

Mesilla and Rincon aquifer systems and the Rio Grande

• Recognizes the need to “keep the river whole”• Recognizes need to clarify obligation to Texas• Ongoing negotiations among EBID, EPCWID,

and Bureau of Reclamation to clarify obligation to Texas

Active Water Resource Management• State administering groundwater in the absence

of a completed adjudication• State’s standard issue tool is priority

administration• Local users have the ability to develop

alternative administration rules• Advantages:

– Future new uses will rely on surface water– Current junior uses can use surface water rights to

move up in priority– Intelligent conjunctive management of surface water

and groundwater is possible• Requires cooperation among LRGWUO

members and State

Old School

• Adversarial

• Egos, conflicting agendas, cloak-and-dagger games clog the process

• Time and money consuming

• Destructive

• Bad for all concerned

A New Paradigm

• Principled negotiation

• Common ground kept in mind

• Cool heads prevail

• Accurate, objective data analysis

• Recognize obligations

From the Rio Grande Joint Investigation:

“… The cordial willingness with which the official representatives of Colorado, New Mexico, and Texas entered into the undertaking exemplified constructive statesmanship… Each of these States is vitally concerned with its own welfare, yet in the Rio Grande Joint Investigation each recognized its obligation to its sister States; each accepted the principle that an equitable adjustment of conflicting interests in the waters of the river is imperative.”

Frank Adams, Harlan H. Barrows

Chairman, Consulting Board, February 1938