Basin Hydrology, Operations 

2018 Hydrograph 

Glen Canyon Technical Work Gro

January 26, 2017 
Snow Conditions 

2 

As of 1-1-2017 

SWE is 121% of median 
Snow Conditions 

3 

As of 1-26-2017 

SWE is 167% of median 
4 

83% 

71% 

47% 

77% 

55% 

1 percent of average based on per

http://www.usbr.gov/uc/water/basin/tc_cr.html 

Reservoir 

A-J 

Forec

(KAF

Fontenelle 930 

Flaming Gorge 123

Blue Mesa 575 

Navajo 580 

Powell 6,50

Basin Storage 

As of 

1/22/2017 

Upper Basin Storage 

April to July 2017 Fore

Issued January 4
5 

83% 

71% 

47% 

77% 

55% 

1 percent of average based on per

http://www.usbr.gov/uc/water/basin/tc_cr.html 

Reservoir 

A-J 

Forec

(KAF

Fontenelle 1130 

Flaming Gorge 153

Blue Mesa 915 

Navajo 750 

Powell 9,00

Basin Storage 

As of 

1/22/2017 

Upper Basin Storage 

April to July 2017 Fore

Issued January 1
6 

Mid-month: 9.0 maf (127%) 
Lake Powell 2017 Operating Tie

Upper Elevation Balancing 

• Tier was set in August 2016

– Start with 8.23 maf release

• Use April 24-Month Study 

projections of end of water year storage to potentially adjust 

1. Stay with 8.23 maf 2. Balancing: 8.23 - 9.0 maf3. Equalization: > 8.23 maf

7 
Lake Powell 2017 Operating Tier Sce

Based on January 2017 modeling 

Inflow 

Scenario 

Operating Tier 

Release Volume 

Minimum 

Probable 

Upper Elevation Balancing 

9.0 maf 

Most 

Probable 

Upper Elevation Balancing 

9.0 maf 

Maximum 

Probable 

Upper Elevation Balancing 

9.0 maf 

8 
LTEMP Monthly Release Volum

Month 7.00 7.48 8.23 9.00 9.50 10.50 11.00 12.00 OCT 480 480 640 640 640 640 640 640 6NOV 500 500 640 640 640 640 640 640 6DEC 600 600 720 720 720 720 720 720 7JAN 660 720 760 860 920 1040 1100 1230 1FEB 590 640 680 750 810 920 970 1080 1MAR 620 675 710 800 860 970 1030 1150 1APR 550 600 640 710 760 870 920 1020 1MAY 550 600 630 710 760 860 910 1020 1JUN 580 630 660 750 800 910 960 1060 1JUL 650 710 750 850 900 1020 1080 1200 1AUG 700 760 800 900 970 1090 1160 1280 1SEP 520 565 600 670 720 820 870 960 1
Unit 

Number 

Oct 

2016 

Nov 

2016 

Dec 

2016 

Jan 

2017 

Feb 

2017 

Mar 

2017 

Apr 

2017 

May 

2017 

Jun 

2017 

Jul 

2017 

1 2 3 4 5 6 7 8 

Units 

Available 6 6 6 6 5 5 7 7 7 7 

Capacity 

(cfs) 21,000 21,000 19,700 19,750 16,200 16,150 23,350 23,350 24,400 23,40

Capacity 

(kaf/month) 1,310 1,280 1,180 1,270 930 1,090 1,390 1,440 1,390 1,440 

Max (kaf) 1 601 750 898 880 715 720 620 646 750 850 

Most (kaf) 2 601 750 898 880 715 720 620 646 750 850 

Min (kaf) 1 601 750 898 880 715 720 620 646 750 850 

10 

Glen Canyon Power Plant Planned Unit Outage Schedule for Water 

1 Projected release, based on Jan 2017 Min and Max Probable 

Inflow Projections and 24-Month Study model runs 

2 Projected release, based on Jan 2017 Most Probable Inflow 

Projections and 24-Month Study model runs 

(up
2017 Hydrograph (9.0 MAF) 

Month LTEMP Release, (kaf) BOR/WAPA Planned 

Release, (kaf) 

Recom

Hydr

OCT 640 601 

NOV 640 750 

DEC 720 898 

JAN 860 880 

FEB 750 715 

MAR 800 720 

APR 710 620 

MAY 710 646 

JUN 750 750 

JUL 850 850 

AUG 900 900 

SEP 670 670 

TOTALS 
12 
13 

April adjustment to 

Balancing releases 

April ad

Equaliza

No April 

Adjustment 

Water Year 2017 

Upper Elevation Balancing Tier 

Initial release of 8.23 maf 

Potential April adjustment 

to Equalization or Balancing 
14 

End of CY 2017 Projection: 

3,601.41 feet 

(Range 3,577 to 3,638 feet) 

Water Year 2

Most: 9.0 

Max: 9.0 

Min: 9.0 
Most Probable End of CY 2017 

Projection: 1,074.3 feet (37% full) 

Most Probable 

Projection: 1,07

End of CY 2016 Elevation: 

1,080.8 feet (39% full) 

15 
Water Year 2018 

Operations & Hydrograp

16 
Unit 

Number 

Oct 

2017 

Nov 

2017 

Dec 

2017 

Jan 

2018 

Feb 

2018 

Mar 

2018 

Apr 

2018 

May 

2018 

Jun 

2018 

Jul 

2018 

1 2 3 4 5 6 7 8 

Units 

Available 7 7/5 5 5 5 5 7 7/8 8 8 

Capacity 

(cfs) 23,400 16,100 16,000 16,000 16,000 16,000 23,400 27,000 27,000 27,00

Capacity 

(kaf/month) 1,440 1,220 1,010 980 890 1,000 1,390 1,590 1,660 1,660 

Max (kaf) 1 640 640 720 1,230 1,080 1,150 1,020 1,020 1,100 1,200 

Most (kaf) 2 640 640 720 860 760 800 710 710 750 840 

Min (kaf) 1 640 740 720 860 760 710 640 640 750 850 

17 

Glen Canyon Power Plant Planned Unit Outage Schedule for Water 

1 Projected release, based on Jan 2017 Min and Max Probable 

Inflow Projections and 24-Month Study model runs 

2 Projected release, based on Jan 2017 Most Probable Inflow 

Projections and 24-Month Study model runs 

(up

Possible HFE 
LTEMP Monthly Release Volumes 2

Month 7.00 7.48 8.23 9.00 9.50 10.50 11.00 12.00 OCT 480 480 640 640 640 640 640 640 6NOV 500 500 640 640 640 640 640 640 6DEC 600 600 720 720 720 720 720 720 7JAN 660 720 760 860 920 1040 1100 1230 1FEB 590 640 680 750 810 920 970 1080 1MAR 620 675 710 800 860 970 1030 1150 1APR 550 600 640 710 760 870 920 1020 1MAY 550 600 630 710 760 860 910 1020 1JUN 580 630 660 750 800 910 960 1060 1JUL 650 710 750 850 900 1020 1080 1200 1AUG 700 760 800 900 970 1090 1160 1280 1SEP 520 565 600 670 720 820 870 960 1

MIN & MOST

MAX 
Questions?

Paul Davidson

801-524-3642

PDavidson@usbr.gov

Hydraulic Engineer, Glen Canyon

Reclamation, Upper Colorado Region

Resource Management Division

Water Resources Group