Law School for Law School for JournalistsJournalists

Colorado Bar AssociationColorado Bar Association

Ken KnoxDivision of Water Resources

March 13, 2007

COLORADOHISTORIC AVERAGE ANNUAL STREAM FLOWS

(acre feet)

OFFICE OF THE STATE ENGINEERCOLORADO DIVISION OF WATER RESOURCES

Prepared by the Hydrographic Branch (2003 Revision)Historic averages obtained from USGS Water-Data Report CO-02

YAMPA

WHITE

LITT

LE S

NA

KE

ELK

NO

. PLA

TT

E

CACHE LA POUDRE

SOUTH PLATTE

NORTH FORKREPUBLICAN

SOUTH FORK REPUBLICAN

NO. FORK

ARKANSAS

NO. FORK

UN

CO

MP

AH

GR

E

McELMO

MANCOS

LA P

LAT

A

AN

IMA

S &

FL

OR

IDA

LOS

PIN

OS

PIED

RA

SAN

JU

AN CONEJOS

PURGATO

IRE

GUNNISON

SAN MIGUELLA

RA

MIE

COLORADO

DO

LO

RE

S

RIO GRANDE

1,531,000

555,200

4,500,000

414,300

1,127,000

404,600

311,100111,800

37,100

36,890 25,580670,100 173,700 446,900

+291,200

235,800

322,100

653,300

394,300

153,000

593,600

172,000

219,800

943,000

330,500547,300

291,200

268,600

1,872,000

125,100

31,890

313,200 96,300

49,640

47,020

164,20089,820

699,200

528,200

879,800

413,200

329,200

45,590476,300

229,200

185,200

403,400

31,680

28,750

69,750

FO

UN

TA

IN

APISHAPA18,970HUERFANO

26,930

GR

AP

E24,933

BEAR

33,760

58,14688,051

63,038

126,800

270,500

204,400

404,400

875,600

265,800 99,500

634,500

ST. VRAIN

BOULDER

158,800

50,050

PIC

EA

NC

E

27,700

152,600

6

5

2

1

34

7

505,600

279,700

2,799,000

334,400

54,760 85,540

EA

ST

TO

WA

RD

AT

LA

NT

IC O

CE

AN

1

,37

3,0

00

af

WE

ST

TO

WA

RD

PA

CIF

IC O

CE

AN

8

,86

7,4

50

af

TOTAL LEAVING COLORADO 10,240,500 af

ROARINGFORK

EAGLE

BLUE

TOMICHI

SOU

THFO

RK

SAN JU

AN - C

HAM

A

94,180

At Benkelman, NE

1,530,000

560,000

310,000

4,500,000

510,000

1,780,000 320,000

110,000 400,000

164,000

YAMPAYAMPA

WHITEWHITE

COLORADOCOLORADO

GUNNISON

GUNNISON

DO

LOR

ESD

OLO

RES

SAN

SA

N

JUA

NJU

AN

ARKANSASARKANSAS

SOUTH PLATTESOUTH PLATTE

N. N. PLATTEPLATTE

LARAMIELARAMIE

RIO GRANDE

RIO GRANDEWEST SLOPEWEST SLOPEPopulation:467,000

Irrigated Acres:880,000

EAST SLOPEEAST SLOPEPopulation:3,869,000

Irrigated Acres:2,270,000

2000 PopulationIrrigated Acres and Flows

Water Management and Allocation

Water Rights– Surface water rights from rivers and streams– Reservoir storage rights– Ground water rights

Interstate River Compacts

Colorado’s Water Right System

Colorado uses the Prior Appropriation Doctrine which means those that first put water to use are entitled to get their water first during periods of water shortage. In Colorado water is a separate property right - that is it can be sold separately from the land. This is in contrast to the Riparian Doctrine that exists in the eastern part of the United States which recognizes water rights as being attached to the land.

Water Administration

• Water Allocation – 173,000 Water Rights– 105,000 Structures– 400,000 observations – 30,000 water diversions and storage records– 1500 court consultations– 50 court litigation – 420 subdivision review– 217 Substitute Water Supply Plans

In 1879, Colorado established Water Commissioners to distribute water rights in priority based upon principle of “First In Time... First In Right”

Reservoir Storage

Current Storage

(acre-feet)

Restricted Storage*

Total acre-feet (# Dams)

Division 1 1,787,810 33,900 (99)

Division 2 893,544 89,200 (31)

Division 3 297,261 9,700 (3)

Division 4 1,447,948 4,200 (28)

Division 5 1,166,040 2,990 (19)

Division 6 165,387 1,400 (11)

Division 7 665,356 1,460 (7)

Total 6,423,345 142,850 (198)

* August 20, 2002• 1990 – 2001: 49 new dams with a combined storage of 120,000 acre-feet• Division 2: Two Buttes 31,500 AF and Cucharas 33,000 AF; very

expensive reconstruction necessary

Major Aquifer Systems

GROUND WATER USE

AQUIFER AVERAGE ANNUAL SUPPLY

(Acre-Feet)

Denver Basin 80,000

South Platte Alluvium 600,000

Arkansas River Alluvium 150,000

San Luis Valley Aquifers 800,000

High Plains – Ogallala 1,000,000

Bedrock Aquifers – Mountains 70,000

TOTAL 2,700,000

18 States Rely on Colorado Water18 States Rely on Colorado Water

Interstate Compacts

Colorado River Compact - 1922La Plata River Compact - 1922South Platte River Compact - 1923Rio Grande River Compact - 1938Republican River Compact - 1942Costilla Creek Compact - 1944 (Rev. 1963)Upper Colorado River Compact - 1948Arkansas River Compact - 1948Animas-La Plata Project Compact - 1969

U.S. Supreme Court Cases

Nebraska v. Wyoming - 325 U.S. 589 (1945)Wyoming v. Colorado - 353 U.S. 953 (1957)

INTERNATIONAL AND INTERSTATE DOCUMENTS AFFECTING COLORADO’S USE OF WATER

International Treaties

Mexican Treaty on Rio Grande, Tijuana,

and Colorado’s Rivers – 1945

1906 Convention with Mexico on the Rio Grande above Ft. Quitman,

Texas

SSTATETATE O OFF C COLORADOOLORADO I INTERSTATENTERSTATE CCOMPACTSOMPACTS

Methods of Allocating Water Among States1 Allocation of a portion of the long-term undepleted basin water

supply to each state on the basis of consumptive use (man-made depletions)

a Colorado River Compact - Acre-feet per year of depletionsb Republican River Compact - Acre-feet per year of depletions

2 Delivery of a portion of an indexed supply to the statelinea Rio Grande Compact - Variable index and delivery obligation

for calendar yearb La Plata River Compact - One-half of indexed flow to

stateline the next day

3 Application of Doctrine of Prior Appropriation across statelinea Costilla Creek Compactb South Platte River Compact

Thank YouThank You

http://www.water.state.co.us/