Colorado River Water Availability Study

Colorado Water WorkshopGunnison, Colorado

July 21, 2010

Colorado River Water Availability Study

Colorado Water WorkshopGunnison, Colorado

July 21, 2010CWCB Project

ManagerRay Alvarado

Consulting TeamAECOM

AMEC Earth & Environmental

Canyon Water ResourcesLeonard Rice Engineers

Stratus Consulting

“How much water from the Colorado River Basin is available to meet Colorado's water needs?“

• Phase IWater Availability under current infrastructure, currently perfected water rights, and current levels of consumptive and non-consumptive water demands

• Phase IIWater Availability under projected demands from existing, conditional, and new water rights and for additional consumptive and non-consumptive water demands

ObjectivesObjectives

2 Colorado River Water Availability Study – Phase I

1500 20991950 2005 2040 2070

StateModStateCU

Statistical Models

Observed Hydrology

Overall Hydrology ApproachOverall Hydrology Approach

GCM’s & Hydrology

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

AF

UNCOMPAHGRE RIVER AT DELTA USGS (09149500)2040 Average Monthly Natural Flow

Range

Historical Average

Individual Model Results

Average Annual Natural Flow Ranges f rom 200,000 to 347,000 AF

Paleohydrology

0

2

4

6

8

10

12

14

16

18

20

1520

1533

1546

1559

1572

1585

1598

1611

1624

1637

1650

1663

1676

1689

1702

1715

1728

1741

1754

1767

1780

1793

1806

1819

1832

1845

1858

1871

1884

1897

1910

1923

1936

1949

1962

1975

1988

2001

Year

3 Colorado River Water Availability Study – Phase I

1977 1983Douglas-fir, south-central CO

From NOAA,

0.0

5.0

10.0

15.0

20.0

25.0

19

73

19

74

19

75

19

76

19

77

19

78

19

79

19

80

19

81

19

82

19

83

19

84

NOAA treeflow.info

Basis for Paleo-HydrologyBasis for Paleo-Hydrology

4 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study – Phase I

Hist

WGM1

(1536-1997)

WGM2

(1536-1997)

SRP

(1520-1964)

Hidalgo

(1520-1962)

Stockton1

(1520-1961)

Stockton2

(1520-1961)

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

1520

1534

1548

1562

1576

1590

1604

1618

1632

1646

1660

1674

1688

1702

1716

1730

1744

1758

1772

1786

1800

1814

1828

1842

1856

1870

1884

1898

1912

1926

1940

1954

1968

1982

1996

Re-sequencing – The MotivationRe-sequencing – The Motivation

5 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study – Phase I

1.

19

77

19

84

19

84

19

77

Repeat 100x

Paleohydrology – Re-sequencingPaleohydrology – Re-sequencing

1950 Years 20056 Colorado River Water Availability Study – Phase I

1500 20991950 2005 2040 2070

StateModStateCU

Statistical Models

Paleohydrology

0

2

4

6

8

10

12

14

16

18

20

1520

1533

1546

1559

1572

1585

1598

1611

1624

1637

1650

1663

1676

1689

1702

1715

1728

1741

1754

1767

1780

1793

1806

1819

1832

1845

1858

1871

1884

1897

1910

1923

1936

1949

1962

1975

1988

2001

Year

Observed HydrologyGCM’s & Hydrology

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

AF

UNCOMPAHGRE RIVER AT DELTA USGS (09149500)2040 Average Monthly Natural Flow

Range

Historical Average

Individual Model Results

Average Annual Natural Flow Ranges f rom 200,000 to 347,000 AF

Overall Hydrology ApproachOverall Hydrology Approach

7 Colorado River Water Availability Study – Phase I

Colorado River Basin• “Down-Scaled” Projections• Revised Basin-Wide HydrologyResult: Altered Stream Flows

Earth• Emissions Scenarios• Global Climate ModelsResult: Altered Temperature

and Precipitation State of Colorado• CDSS ModelingResult: Water Availability

GCMs and HydrologyGCMs and Hydrology

8 Colorado River Water Availability Study – Phase I

19

77

19

84

Climate Effect

Act

ual

Clim

ate

Adj

uste

d

Actual

Climate Adjusted

} Climate Effect

GCM Hydrology ProcessGCM Hydrology Process

9 Colorado River Water Availability Study – Phase I

1500 20991950 2005 2040 2070

StateModStateCU

Statistical Models

Paleohydrology

0

2

4

6

8

10

12

14

16

18

20

1520

1533

1546

1559

1572

1585

1598

1611

1624

1637

1650

1663

1676

1689

1702

1715

1728

1741

1754

1767

1780

1793

1806

1819

1832

1845

1858

1871

1884

1897

1910

1923

1936

1949

1962

1975

1988

2001

Year

Observed HydrologyGCM’s & Hydrology

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

AF

UNCOMPAHGRE RIVER AT DELTA USGS (09149500)2040 Average Monthly Natural Flow

Range

Historical Average

Individual Model Results

Average Annual Natural Flow Ranges f rom 200,000 to 347,000 AF

Overall Hydrology ApproachOverall Hydrology Approach

10 Colorado River Water Availability Study – Phase I

11 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study | Phase I

100,000

200,000

300,000

400,000

500,000

600,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

AF

Yampa River near Maybell (09251000)2040 Average Monthly Natural Flow

Range of Model Results

Historical Average

Individual Model Results

Average Annual Natural Flow Ranges f rom 1,110,000 to 1,520,000 AF

Natural Flow ResultsNatural Flow Results

12 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study | Phase I

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

180,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

AF

White River near Colorado State Line, UT (09306395)2040 Average Monthly Natural Flow

Range of Model Results

Historical Average

Individual Model Results

Average Annual Natural Flow Ranges f rom 396,000 to 630,000 AF

Natural Flow ResultsNatural Flow Results

13 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study | Phase I

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

AF

Colorado River near Grand Lake (09011000)2040 Average Monthly Natural Flow

Range of Model Results

Historical Average

Individual Model Results

Average Annual Natural Flow Ranges f rom 72,800 to 96,500 AF

Natural Flow ResultsNatural Flow Results

14 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study | Phase I

200,000

400,000

600,000

800,000

1,000,000

1,200,000

1,400,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

AF

Colorado River near Cameo (09095500)2040 Average Monthly Natural Flow

Range of Model Results

Historical Average

Individual Model Results

Average Annual Natural Flow Ranges f rom 2,810,000 to 4,040,000 AF

Natural Flow ResultsNatural Flow Results

15 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study | Phase I

10,000

20,000

30,000

40,000

50,000

60,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

AF

Taylor River below Taylor Park Reservoir (09109000)2040 Average Monthly Natural Flow

Range of Model Results

Historical Average

Individual Model Results

Average Annual Natural Flow Ranges f rom 120,000 to 168,000 AF

Natural Flow ResultsNatural Flow Results

16 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study | Phase I

50,000

100,000

150,000

200,000

250,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

AF

Gunnison River near Gunnison (09114500)2040 Average Monthly Natural Flow

Range of Model Results

Historical Average

Individual Model Results

Average Annual Natural Flow Ranges f rom 483,000 to 660,000 AF

Natural Flow ResultsNatural Flow Results

17 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study | Phase I

100,000

200,000

300,000

400,000

500,000

600,000

700,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

AF

Gunnison River at Delta (09144250)2040 Average Monthly Natural Flow

Range of Model Results

Historical Average

Individual Model Results

Average Annual Natural Flow Ranges f rom 1,550,000 to 2,290,000 AF

Natural Flow ResultsNatural Flow Results

18 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study – Phase I

Natural FlowNatural Flow

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

AF

Uncompahgre River at Delta (09149500)2040 Average Monthly Natural Flow

Range of Model Results

Historical Average

Individual Model Results

Average Annual Natural Flow Ranges f rom 204,000 to 354,000 AF

19 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study | Phase I

20,000

40,000

60,000

80,000

100,000

120,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

AF

San Juan River at Pagosa Springs (09342500)2040 Average Monthly Natural Flow

Range of Model Results

Historical Average

Individual Model Results

Average Annual Natural Flow Ranges f rom 215,000 to 327,000 AF

Natural Flow ResultsNatural Flow Results

20 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study | Phase I

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

180,000

200,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

AF

Animas River at Durango (09361500)2040 Average Monthly Natural Flow

Range of Model Results

Historical Average

Individual Model Results

Average Annual Natural Flow Ranges f rom 387,000 to 652,000 AF

Natural Flow ResultsNatural Flow Results

Natural Flow ResultsNatural Flow Results

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

180,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

AF

DOLORES RIVER NEAR BEDROCK (09171100)2040 Average Monthly Natural Flow

Range of Climate Model Natural Flows

Historical Natural Flow

Individual Climate Model Natural Flows

21 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study – Phase I

Result Summary – Natural FlowResult Summary – Natural Flow

22 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study – Phase I

• Annual flow increases in some possible futures and decreases in others

• Annual flow generally increases in parts of the Yampa River basin and at higher elevation watersheds

• Annual flow generally decreases in south-western watersheds and at lower elevations

• Shifts toward earlier peak runoff

• Flow decreases in late summer and early fall

• Ranking of uncertainties (Wilby & Harris, 2005), largest to smallest:– GCM Projections – Downscaling method– Hydrology model structure– Hydrology model parameters– Emissions scenarios

• Uncertainties interact, but are not additive.

23 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study | Phase I

Uncertainties—Natural FlowUncertainties—Natural Flow

All projections, Glenwood SpringsAll projections, Glenwood Springs

24 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study | Phase I

0

500000

1000000

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350000019

7919

8519

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Axi

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tle

All projections GWS

Ensemble of GCMs, Glenwood SpringsEnsemble of GCMs, Glenwood Springs

25 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study | Phase I

0

500000

1000000

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3000000

1979

1985

1991

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2015

2021

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2075

2081

2087

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Axi

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tle

cccma_cgcm3

0

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1000000

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2000000

2500000

1979

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2015

2021

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s Ti

tle

gfdl_cm2

0

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1000000

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2000000

2500000

1979

1985

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2009

2015

2021

2027

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2057

2063

2069

2075

2081

2087

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2099

Axi

s Ti

tle

miroc3_2_medres

0

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1000000

1500000

2000000

2500000

1979

1985

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2009

2015

2021

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s Ti

tle

miub_echo_g

0

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3000000

1979

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2015

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s Ti

tle

mri_cgcm2_3_2a

0

500000

1000000

1500000

2000000

2500000

3000000

1979

1985

1991

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2009

2015

2021

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2039

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2057

2063

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2081

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2093

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Axi

s Ti

tle

ncar_ccsm3_0

0

500000

1000000

1500000

2000000

2500000

3000000

3500000

1979

1985

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2003

2009

2015

2021

2027

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2039

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s Ti

tle

ncar_pcm1

0

500000

1000000

1500000

2000000

2500000

1979

1985

1991

1997

2003

2009

2015

2021

2027

2033

2039

2045

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2063

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s Ti

tle

csiro mk3

0

500000

1000000

1500000

2000000

2500000

1979

1985

1991

1997

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2009

2015

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2027

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2057

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Axi

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tle

giss_model_e_r

Precipitation Time Series, Lees FerryPrecipitation Time Series, Lees Ferry

26 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study | Phase I

0

20000000

40000000

60000000

80000000

100000000

120000000

1979

1985

1991

1997

2003

2009

2015

2021

2027

2033

2039

2045

2051

2057

2063

2069

2075

2081

2087

2093

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Axi

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P All projections

Temperature Time Series, Lees FerryTemperature Time Series, Lees Ferry

27 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study | Phase I

0

2

4

6

8

10

12

14

1979

1985

1991

1997

2003

2009

2015

2021

2027

2033

2039

2045

2051

2057

2063

2069

2075

2081

2087

2093

2099

Axi

s Ti

tle

T All projections

Natural Flow Time series at Lees FerryNatural Flow Time series at Lees Ferry

28 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study | Phase I

02000000400000060000008000000100000001200000014000000160000001800000020000000

1979

1985

1991

1997

2003

2009

2015

2021

2027

2033

2039

2045

2051

2057

2063

2069

2075

2081

2087

2093

2099

Axi

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All projections

• Phase I demonstrates broad range of impacts to natural flows.– Complexity of modeling atmospheric

circulation

– Inherent uncertainties in GCM projections

• Robust results– Increased temperatures

– Less snowpack and earlier melt

ConclusionsConclusions

29 PRELIMINARY RESULTS – UNDER REVIEW Colorado River Water Availability Study – Phase I