2016 Glen Canyon Dam 

Annual Operating Plan 

Technical Work Group Meeting 

October 21, 2015 
Colorado River 

Annual Operating Plan 

2 
Colorado River Annual Operatin

• Report of Colorado River hydrology and reservoir 

for past year and projections for the upcoming yea

• Purpose: Illustrate range of reservoir operations th

be expected in the upcoming water year 

• Reflects operational rules, guidelines and decision

have been put into place for the Colorado River re

• AOP document is prepared by Reclamation, in co

with representatives of the Basin States, Indian TrUpper Colorado River Commission, appropriate Fagencies, and other Basin stakeholders. Typically consultation meetings. 

• 2016 AOP currently in final stages of developmen

transmittal to Secretary of Interior in upcoming wehttp://www.usbr.gov/uc/water/rsvrs/ops/aop/index.

3 
Hydrology and 

Reservoir Operations 

Water Years 2015 and 201
5 

Snow Conditions for WY 2015 

Seasonal snowpack 

peaked at 74% on 

March 9th 

Very wet May 
6 

91% 

83% 

51% 81% 

70% 

1 percent of average based on per

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

Basin Storage 

As of 

10/19/2015 

Upper Basin Storage 

Water Year 2

Observed Unregula

Reservoir 

WY 20

Observ

(KAF

Fontenelle 1,210 

Flaming 

Gorge 1,560 

Blue Mesa 1,040 

Navajo 900 

Powell 10,17
Observed WY 2015: 

7 

* Decrease from Sept forecast: 840kaf 
Lake Powell Operational Tier 

Determinations (2007 Interim Guide

• August 24-Month Study projection of January 1 e

establishes the Lake Powell operating Tiers for thupcoming year 

• If in Upper Elevation Balancing, April 24-Month S

projection of Sept 30th elevation / storage could s

Powell operations to balancing or equalization foremainder of water year 

• Reservoir operating plans are continually update

throughout the water year as hydrologic and opeconditions change. 

8 
Lake Powell & Lake Mead Operational Ta

Operational Tiers for Water/Calendar Year 2016 determined with the August 2015 

9 

3,602.46 ft 

Aug 2014 

projection of 

Jan 1,2015 

p

J
Lake Powell Operational Scenarios

Based on October 2014 24-Month Study Inflow Scenarios 

Powell Inflow 

Scenario 

WY 2015 

Release Projection 

Probable 

Minimum 

Upper Elevation Balancing Tier 

w/ Projected April shift to Balancing 

9.0 maf release 

Most 

Probable 

Upper Elevation Balancing Tier 

w/ Projected April shift to Balancing 

9.0 maf release 

Probable 

Maximum 

Upper Elevation Balancing Tier 

w/ Projected April shift to Equalization 

11.4 maf release 

10 
11 
12 

Monthly distribution will change if 2016 Hydrograph is approved by Secretary 
13 

Water Year 2016 

Upper Elevation Balancing Tier 

Initial release of 8.23 maf 

Potential April adjustment 

to Equalization or Balancing 

April adjustment to Balancing releases 

April adjuEqualizati

No April Adjustment 
Water Year 20

Most: 9.0 maf Max: 11.4 maf Min: 9.0 maf re

14 
Lake Mead as of 10/20/15: 

1,079 feet, 38% of capacity 

End of CY 1,077.8 fee(Range: 1,0

15 
Questions? 

16 
–

–

–– = –

= = 

–

–

 -

Percent of Traces with Event or System ConditioResults from August 2015 CRSS1,2,3 (values in percent) 

Event or System Condition 2016 2017 201

Upper 

Basin 

– 

Lake 

Powell 

Equalization Tier 

Equalization annual release > 8.23 maf Equalization annual release = 8.23 maf 

8 

8 0 

24 

23 

0 

Upper Elevation Balancing Tier 

Upper Elevation Balancing annual release > 8.23 maf Upper Elevation Balancing annual release 8.23 maf Upper Elevation Balancing annual release < 8.23 maf 

92 

82 10 

0 

52 

39 13 

0 

Mid-Elevation Release Tier 

Mid-Elevation Release – annual release 8.23 maf Mid-Elevation Release – annual release 7.48 maf 

0 

0 0 

24 

0 

24 

Lower Elevation Balancing Tier 0 0 

Lower 

Basin 

– 

Lake 

Mead 

Shortage Condition any amount (Mead ≤ 1,075 ft) 

Shortage – 1st level (Mead ≤ 1,075 and ≥ 1,050) 

Shortage – 2nd level (Mead < 1,050 and ≥ 1,025) 

Shortage – 3rd level (Mead < 1,025) 

0 

0 0 0 

18 

18 

0 0 

Surplus Condition any amount (Mead ≥ 1,145 ft) 

Surplus – Flood Control 

0 

0 

0 

0 

Normal or ICS Surplus Condition 100 82 

1 Reservoir initial conditions based on December 31, 2015 conditions using projections from the most probable August 2015 22 Results are based on 107 hydrologic inflow sequences based on resampling of the observed natural flow record from 1906 23 Percentages shown may not be representative of the full range of future 

possibilities that could occur with different modeling assumptions. 

17 
1,219.6 

Lake Powell Lake Mead 3,700 24.322 maf 

Not to Scale 

9.5 maf 

17.0 maf 

1,145 1,075 

3,648 3,575 

2.5 

maf 

1.9 

maf Dead Storage Dead Storage

0.0 maf 3,370 895 0.0 maf

1,105 

5.9 maf 3,525 1,025 6.0 

1,078.10 feet 

9.9 maf in storage 

38% of capacity 

3,606.01 feet 

12.3 maf in storage 

51% of capacity 

End of Water Year 2015 Conditio

9.00 maf 

Observed Unregulated Inflow into Powell1 = 10.17 maf (94% of 

1 Percent of average inflow is based on the 30-year period 

of record from 1981-2010 . 18 
2016 Possible Hydrograp

8.23 maf release scenario 

19 
2016 Proposed Hydrogra

9.0 maf release scenario 

20 
2016 Proposed Hydrogra

11.7 maf release scenario 

• Lots of water to move: limited flexibility, minimal difference 

21