“There’s No Business Like Snow Business!”

Hydrology of the Blue River, Colorado

Alison SkwarskiGIS for Water Resources

November 30, 2006

Photo courtesy of USGS – taken by Cora Winter

Motivation – Blue Watershed

• Located along the western side of the continental divide – 50 miles west of Denver in the Rocky Mts.

• Easternmost part of HUC Region 14 – Upper Colorado Basin

• Size: 1769.8 km² ~ 683 mi²

•Dillon Reservoir provides drinking water to Denver

Courtesy of USGS – taken by Lane Wyatt

Colorado

Blue

Pueblo

Denver

Boulder

Fort Collins

Grand Junction

Colorado SpringsColorado

Blue

Pueblo

Denver

Boulder

Fort Collins

Grand Junction

Colorado Springs

Objective

- Recognize the specific relationships between the annual snow depth in the winter and the stream flow intensity during  the spring

- Determine impacts of the reservoir and dam on the watershed

- Investigate the reservoir levels in response to the snowfall, precipitation, and stream flow  

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!Climax

Kokomo

Frisco

Dillon

Montezuma

Blue River

Breckenridge

Silverthorne

Legend! Cities

! USGSgages

! Snotel

! PrecipStations

²Blue River runs through the Blue Watershed

Headwaters in the mountains near Hoosier Pass

Drains to the Dillon Reservoir, water storage facility for Denver

Dam is earth filled and the reservoir has a 3,233 acre surface area

Blue River continues north to the Green Mountain Reservoir

0 7 143.5 Miles

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! Legend! USGSGages

NHDFlowlineflowlineattributesflow.MAFLOWU

0.00040 - 14.50967

14.50968 - 62.98479

62.98480 - 247.11310

247.11311 - 634.84409

634.84410 - 2146.58430

²

ElevationValue

High : 4346.89

Low : 2095

USGSgages

What’s going on here?! NHD flowlines are not

connected

Elevation in meters

²

SNOTEL

Snow Water Equivalent (SWE) is a common snowpack measurement. It is the amount of water contained within the snowpack. It can be thought of as the depth of water that would theoretically result if you melted the entire snowpack instaneously.   Useful for stream forecasting

March 2002 March 2005

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Legend!( Snotel

mar2002<VALUE>

8.00 - 8.34

8.34 - 8.67

8.67 - 9.00

9.00 - 9.34

9.34 - 9.67

9.67 - 10.00

10.00 - 10.33

10.33 - 10.67

10.67 - 11.00

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Legend!( Snotel

mar2005<VALUE>

9.63- 9.76

9.76 - 9.90

9.90 - 10.03

10.03 - 10.17

10.17 - 10.31

10.31- 10.44

10.44 - 10.58

10.58 - 10.7

10.71 - 10.85

Snow Water Equivalence Rasters

April 2002 April 2005

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Legend!( Snotel

april2002<VALUE>

5.01 - 5.79

5.79 - 6.56

6.56 - 7.34

7.34 - 8.12

8.12 - 8.89

8.89 - 9.67

9.67 - 10.45

10.45 - 11.22

11.22 - 12.00

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Legend!( Snotel

april2005<VALUE>

11.04 - 11.29

11.29 - 11.55

11.55 - 11.80

11.80 - 12.05

12.05 - 12.30

12.30 - 12.55

12.55 - 12.80

12.80 - 13.05

13.05 - 13.31

Snow Water Equivalence Rasters

May 2002 May 2005

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Legend!( Snotel

may2002<VALUE>

0 - 1

1 - 2

2 - 3

3 - 4

4 - 5

5 - 6

6- 7

7- 8

8- 9

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Legend!( Snotel

may2005<VALUE>

2.02 - 3.68

3.68 - 5.34

5.34 - 7.01

7.01 - 8.67

8.67 - 10.34

10.34 - 12.00

12.00 - 13.66

13.66 - 15.33

15.33 - 17.00

Snow Water Equivalence Rasters

0

100

200

300

400

500

600

700

800

Jan-02 May-02 Oct-02 Mar-03 Aug-03 Jan-04 Jun-04 Nov-04 Apr-05 Sep-05 Feb-06 Jul-06

Date

Stre

amflo

w, c

fs

0

5

10

15

20

25

Snow

Wat

er E

quiv

ilant

(in)

Streamflow- Blue River near DillonSWE - Hoosier Pass

Figure 1: Comparison of Snow Water Equivalence and Streamflow from 2002 to 2006

Impacts of the Dam on the Streamflow

Figure 2: USGS Streamflow Blue River below Dillon after the Dam

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200

400

600

800

1000

1200

12/31/2001 7/19/2002 2/4/2003 8/23/2003 3/10/2004 9/26/2004 4/14/2005 10/31/2005 5/19/2006

Date

Stre

amflo

w, c

fs

Blue River below DamBlue River near DillonBlue River at Blue River

Figure 3: Comparison of Precipitation and Streamflow from 2002 to 2006

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!Climax

Kokomo

Frisco

Dillon

Montezuma

Blue River

Breckenridge

Silverthorne

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200

400

600

800

1000

1200

1400

1600

1800

12/31/2001 7/19/2002 2/4/2003 8/23/2003 3/10/2004 9/26/2004 4/14/2005 10/31/2005 5/19/2006

Date

Stre

amflo

w, c

fs

Blue River below DamBlue River below Green Mt Reservoir

Figure 4: Further Downstream Comparisons of Streamflow²

Conclusions

Snowpack contributes greatly to the stream flow intensity of the Blue River

Dillon Dam greatly influences the downstream flow of the Blue River in the watershed

To be completed: Investigate the reservoir levels in response to the

snowfall, precipitation, and stream flow

Questions?

Can you spot the chipmunk in this photo?