Page 1 

Glen Canyon Dam Technical Work Group 

Agenda Item Information 

October 28-29, 2014 

Agenda Item 

Planning for a Fall 2014 High Flow Experiment 

Action Requested 

Information item only 

Presenter 

Glen Knowles, Chief, Adaptive Management Group, Environmental Resources Division, Upper 

Colorado Region, Bureau of Reclamation (Reclamation) 

Previous Action Taken 

N/A 

Relevant Science 

The Environmental Assessment and Finding of No Significant Impact for Development and 

Implementation of a Protocol for High-Flow Experimental Releases from Glen Canyon Dam, 

Arizona, 2011 through 2020 can be found here: http://www.usbr.gov/uc/envdocs/index.html

Background Information 

The Finding of No Significant Impact for the Development and Implementation of a Protocol for 

High-Flow Experimental Releases from Glen Canyon Dam, Arizona, 2011 through 2020 (HFE 

Protocol) was completed in May of 2012 along with a directive from the Secretary of the Interior on 

the implementation of the HFE Protocol and Non-native Fish Control in Grand Canyon. The 

directive and later guidance from the Assistant Secretary of the Interior for Water and Science, 

created the DOI Glen Canyon Leadership Team which is charged with determining when HFEs will 

be implemented under the HFE Protocol, and an HFE Technical Team that evaluates resource 

conditions and provides a recommendation to the DOI Glen Canyon Leadership Team on 

implementation of individual HFEs. 

As of October 22, 2004, GCMRC estimated that 1.95 million metric tons of sand had entered the 

Colorado River from the Paria River since July 1, 2014. Based on that amount, GCRMC 

recommends conducting the largest HFE allowable under the HFE Protocol. Reclamation estimates 

that 7 of 6 units will be available at Glen Canyon Dam to conduct an HFE in November, and that a 

maximum of 37,500 cfs release will be possible given the outage of one unit and other factors such 

as the need to maintain 40 MW of system regulation. If a fall 2014 HFE were to occur, the HFE 

would be of 37,500 cfs magnitude for 96 hours, and would occur from November 10-15, 2014. The 

planning process and related materials will be reviewed in the presentation. 
Fall 2014 HFE Planning

Glen Knowles

Bureau of Reclamation

Technical Work Group

October 17, 2014
1. Planning and Budgeting Component

 Annual resource status assessment

 Annual Agency Reporting

 GCDAMP Budget and Work Plan Process

2. Modeling Component

3. Decision and Implementation Component

 Review Modeling Component

 Review Status of Resources

 Consultation with agencies and tribes, AMWG 

and TWG input

 Staff Recommendation/DOI GCD Leadership 

Team Recommendation

HFE Decision Making Process

2
Modeling Component

3
HFE Protocol Parameters

Possible Timing

– March-April and October-November through 2020

– Spring HFEs will not be considered until 2015

Duration range

– 1 hr – 96 hrs (at full magnitude)

– 1 1⁄2 days – 6 1⁄2 days (including ramping)

Magnitude range

– 31,500 cfs – 45,000 cfs (depends on maintenance)

– 2014 projected available release for November is 37,500 cfs (7 of 8 

units available)

Ramping rates

– Ramping rates are defined by 1996 ROD and 1997 Glen Canyon Dam 

Operating Criteria (62 FR 9447, 4,000 cfs up and 1,500 cfs down)

4
5

Current conditions

from the GCMRC

web page as of Oct. 17

Paria River at Lees Ferry 

discharge since July 1

Paria River at Lees Ferry 

cumulative sand load

since July 1

1.94 mmt
6

K. Stout

Preliminary data

Do not cite

Lower bound 

0.91 mmt
7

K. Stout

Preliminary data

Do not cite
98
Possible Monthly Release Volumes

Monthly release patterns are provisional and subject to change.

Water Year 2015

9
Resource Status Assessment

Sediment Resources

In-channel sediment storage

Sandbar campable area

High-elevation sand deposits

Cultural Resources

Archaeological site condition and stability

Access to archaeological sites by tribes

Biological Resources

Aquatic food base

Lees Ferry trout population

Lees Ferry fishery recreation experience quality

Endangered humpback chub and other fish abundance

Riparian vegetation

Hydropower and water delivery

Water quality

Water delivery

Dam maintenance

Hydropower production and marketable capacity

10
Cultural Resources

 HFE-caused erosion is a 

consideration, most sites 

already mitigated.

 The HFE MOA requires 

reporting and consultation 

after HFEs

 No impacts to sites were 

identified from the 2012 HFE, 

no reports of issues with 

access to sites

 The MOA for the HFE Protocol 

requires notification to all the 

consulting parties at least 30 

days in advance of a HFE and 

will consult with tribes to 

resolve any issues

 A 30-day notification letter 

notifying MOA signatories of 

a possible HFE in November

Reclamation met with MOA signatories 

Feb. 12, 2014 to review effects of 2013 

HFE and found none

11
Hydropower/Socioeconomic Impacts

 HFEs impact hydropower 

production: 

 Water released during 

an HFE counts against 

the annual release and 

is not available to be 

programmed in peaking 

releases during high 

demand months (HFE 

windows of Mar/Apr 

and Oct/Nov are lowdemand shoulder 

months).

 30-40% of HFE releases 

bypass the power plant.

 Lake Powell is lowered, 

reducing hydrologic 

head.

Western Area Power 

Administration estimates annual 

hydropower impacts of $1.777M 

from Fall 2014 HFE

12
RM 22 R – Returned to pre-HFE size by February (about same response as 2012)

11/18/2013

11/11/2013 0

1

02/12/2014 0

05/02/2014 0

13
RM 51 L – Still larger in May 2014 (not a “gainer” for 2012 HFE)

11/18/2013

11/11/2013 0

2

02/12/2014 1

05/03/2014 1

14
Sandbar Response to 2013 HFE based 

on Analysis of Images from Remote 

Cameras

• Response immediately after 2013 HFE

– Substantial Gain (deposition): 21 sandbars (50% of sites)

– No substantial change: 16 sandbars (38% of sites)

– Substantial Loss (erosion): 5 sandbars (12% of sites)

• 2013 HFE compared to 2012 HFE

– Sandbar larger after 2013 HFE: 9 sandbars (27% of sites)

– Sandbar larger after 2012 HFE : 2 sandbars (6% of sites)

– About the same: 22 sandbars (67% of sites)

Preliminary data

Response to 2013 HFE similar to previous 

HFEs: substantial deposition followed by 

erosion of about half the new deposits with 6 

months 

15
Adult and Sub-Adult Humpback Chub 

Abundance Estimates

(S. Martell, preliminary data, do not cite)

Abundance estimates 

for adults (age 4+)

Abundance estimates for 

sub-adults (age 2+)

ASMR abundance estimate: 

> 7,000 adult Humpback 

Chub. Uncertainty likely 

considerably underestimated.

16
Adult Humpback Chub Abundance Estimates: 

Multistate Population Model

(Yackulic et al. 2014)

Suggests adult Humpback 

Chub abundance stable from 

2009 – 2012. Confidence 

intervals provide reasonable 

estimates of uncertainty.

17
0

2000

4000

6000

8000

10000

12000

April 92

May 92

June 92

May 01

April/May 02April/May 03April/May 04April/May 05April/May 06April/May 07April/May 08April/May 09

May/June 10May/June 11

April/May 12April/May 13

April/May 2014

Abundance estimate

>=150 mm TL >=200 mm TL

Annual spring abundances of humpback chub ≥ 150 

mm and ≥ 200 mm in lower 13.6 km of LCR

2014 spring estimates 

indicate Humpback Chub 

abundance stable in the LCR

(Preliminary data from VanHaverbeke et al. 2014, Do Not Cite)

18
(Preliminary Data from Yackulic 2014. Do Not Cite.)

Juvenile humpback chub 

survival increased over 2012-

2013 interval. 2013-2014 

estimate available late 2014.

Annual Survival of Humpback Chub (40-99 

mm) in the Colorado River Study Site

Sampling Interval

Annual Survival Rate

19
0

500

1000

1500

2000

2500

3000

3500

May 2001

April/May 2002April/May 2003April/May 2004April/May 2005April/May 2006April/May 2007April/May 2008April/May 2009

May/June 2010May/June 2011

April/May 2012April/May 2013April/May 2014

Abundance estimate

Year

Spring LCR 150-199 mm humpback 

chub abundance estimates 2014 spring abundance 

estimate of 150-199 mm 

HBC = 2175 

(95% CI: 1861-2489)

(Preliminary Data from VanHaverbeke et al. 2014, Do Not Cite)

20
21
22
Reach I

Apr12Jul12Sep12Jan13Apr13Jul13Sep13Jan14Apr14Jul14

5

10

15

20

Reach II

Apr12Jul12Sep12Jan13Apr13Jul13Sep13Jan14Apr14Jul14

4

6

8

10

12

Reach III

Apr12Jul12Sep12Jan13Apr13Jul13Sep13Jan14Apr14Jul14

1.5

2.0

2.5

3.0

3.5

4.0

Reach IVa

Apr12Jul12Sep12Jan13Apr13Jul13Sep13Jan14Apr14Jul14

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

Reach IVb

Apr12Jul12Sep12Jan13Apr13Jul13Sep13Jan14Apr14Jul14

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Trip

Abundance ('000s per km)

Rainbow Trout Abundance By Reach

I – Glen Canyon/Lees Ferry

II – House Rock

III – Buck Farm

IVa – Upstream of LCR

IVb – Downstream of LCR

(Preliminary Data from Korman and Yard 2014. Do Not Cite.)

All 2014 abundance estimates 

exceed BiOp trigger level 

(presented as fish/km).

July 2014 estimate very 

preliminary.

23
2011 USFWS Biological Opinion

Non-native Fish Control Trigger

• Adult humpback chub <7000 fish?

• OR

• ALL THREE?

– 3 of 5 years 150-199 mm humpback chub in the LCR drops 

below 910?

– Temperature <12° C for 2 consecutive years at LCR?

– Annual survival of 40-99 mm humpback chub in JCM drops 

25% from preceding year?

No

No

No

No

TBD

24
2011 USFWS Biological Opinion

Non-native Fish Control Trigger

• AND

• Rainbow trout abundance over 760?

• AND

• Brown trout abundance over 50?

Open model estimates exceed threshold 

for all trips to date in 2014 

(Korman and Yard, preliminary data)

Yes

2014 catches lower than in 2013, only 7 total 

caught in Jul. 2014 – catches too low to 

generate abundance estimate

(Yard and Korman, preliminary data)

Unknown

25
1. Resource conditions support a 2014 HFE

2. 37,500 cfs for 96 hours, early-mid Nov. 2014

3. Timing TBD, week of Nov. 9

4. 30-day HFE MOA letter has gone out

5. TWG Webinar Oct. 17 11am-1pm mdt

6. Leadership Team meeting week of Oct. 20

7. US Fish and Wildlife Service report in December

8. If an HFE occurs in FY 2014, convene a 

workshop to review results of first 3 HFEs in 

2015

2014 HFE Summary and Next Steps

26