Sandbar Monitoring for November 

2012 Controlled Flood

USGS Grand Canyon Monitoring and Research Center with 

cooperation from Northern Arizona University, Grand Canyon 

National Park, and Grand Canyon River Guides

Paul Grams, Bob Tusso, & Joe Hazel
HFE Protocol Science Question

• Can sandbar building during HFEs exceed sandbar erosion 

during periods between HFEs, such that sandbar size can be 

increased and maintained over several years?

• Building sandbars 

– High flows to build the bars (relatively low uncertainty)

– Sand supply (relatively high uncertainty)

• Key Monitoring Activities:

– Monitoring sediment flux

– Annual (fall) sandbar monitoring at long-term sites

– Analysis of remote sensing images every 4 years (2002, 

2005, 2009, 2013...)

– In-channel sand storage monitoring
Monitoring and Research for Individual 

High Flows: What do we need to learn?

• We know that the high flows build sandbars and that 

there is variability in sandbar response  Further 

quantification yields little new insight at great 

expense.

• Some Additional monitoring required to:

– Confirm that each high flow is having a positive sandbarbuilding response.

– Evaluate the effect of changing the high flow hydrograph.
Use of remote digital cameras to monitor 

sandbar response

• Digital cameras now installed at 33 (out of 44) of the 

long-term sandbar monitoring sites

– Each camera takes 5 photos daily to capture range of water 

levels and lighting conditions

– Cameras powered by solar panels and can store photos for 

up to 1 year

• Test analysis using images collected before and after 

2008 HFE

– 26 sites with remote cameras (mostly film cameras) and 

pre- and post-HFE surveys
Categorization of Sandbar Changes

Sandbar size (area and volume) evaluated relative to 

pre-flood reference condition (March 2008) on each 

photo:

Rating Apparent change Measured Change

in photos by survey

• 2 Large Increase > 10 % increase

• 1 Small Increase 3 – 10% increase

• 0 Negligible Change -3 – +3% change

• -1 Small Decrease 3 – 10% decrease

• -2 Large Decrease > 10% decrease
Classified Change in Sandbar Size

Mar. 2, 2008 Mar. 11, 2008

“0” “2”

Feb. 27, 2008 Apr. 2, 2008

“0” “1”

Large gain

Small gain

RM 30 R

RM 50 R

Survey: 90% 

increase in volume

Survey: 10% 

increase in volume
Classified Change in Sandbar Size

Mar. 2, 2008 Apr. 2, 2008

“0” “0”

Feb. 13, 2008 Apr. 2, 2008

“0” “-1”

No change

loss

RM 139 R

RM 123 L

Survey: 14% 

decrease in volume

Survey: 6% decrease 

in volume
Comparison of Sandbar Response to 2008 HFE based 

on Topographic Surveys and Analysis of Images

Change Number of sites 

with surveyed 

volume change

Change identified from photos

Deposition 17 sites Deposition at all sites

No change 1 site Erosion

Erosion 4 sites Deposition at 2 sites; no change 

at 1 site; erosion at 1 site

• Photo analysis picks up deposition, 

• May confuse erosion and “no change”
Comparison of Sandbar Response based on 

Topographic Surveys and Analysis of Images

Average response estimated from photographs is consistent 

with average response based on topographic surveys
2012 Controlled Flood

0

10,000

20,000

30,000

40,000

50,000

-10 -5 0 5 10 15 20

1996

2004

2008

2012

DISCHARGE, IN CUBIC FEET PER SECOND

TIME, IN DAYS RELATIVE TO DEPARTURE FROM NORMAL DAM OPERATIONS

• 24 hr. upramp from 7,000 to 43,400 ft3/s

• 24 hr. peak at 43,400 ft3/s

• 53 hr. downramp from 43,400 to 31,200 ft3/s

• 24 hr. downramp from 31,200 to 7,000 ft3/s
Sandbar Response to 2012 HFE based on 

Analysis of Images from Remote Cameras

• Summary of evaluations at 33 sites for 2012 HFE 

response

– Substantial Gain (deposition): 18 sandbars (55% of sites)

– No substantial change: 12 sandbars (36% of sites)

– Substantial Loss (erosion): 3 sandbars (9% of sites)

• Downstream trends

– All sites between RM 0 and RM 32 increased

– Downstream from RM 32, split between sites of 

noticeable gain and no change, with a few showing 

noticeable loss
RM 2.5 L

11/18/2012 0 11/24/2012 1

RM 8 L

11/18/2012 0 11/24/2012 1

Substantial Gain (18 sites)
RM 9 L

11/18/2012 0 11/24/2012 1

RM 16 L

11/18/2012 0 11/24/2012 1
11/17/2012 0 11/26/2012 2

RM 22 R

11/18/2012 0 11/27/2012 1

RM 30 R
11/17/2012 0 11/28/2012 1

RM 32 R

11/18/2012 0 11/28/2012 2

RM 45 L
11/17/2012 0 11/28/2012 2

RM 65.1 R

11/17/2012 0 11/29/2012 1

RM 66.1 L
10/09/2012 0 12/01/2012 1

RM 68.8 R

11/17/2012 0 11/25/2012 1

RM 81 L
11/18/2012 0 11/25/2012 1

RM 94 L

11/18/2012 0 11/26/2012 1

RM 104 R
11/18/2012 0 11/26/2012 2

RM 119.4 R

11/18/2012 0 11/27/2012 1

RM 145 L
11/18/2012 0 11/27/2012 1

RM 183 R

11/18/2012 0 11/28/2012 1

RM 202 R
RM 41 R

11/18/2012 0 11/27/2012 0

11/18/2012 0 11/28/2012 0

RM 43 L

No Substantial Change(12 sites)
RM 44 L

11/18/2012 0 11/28/2012 0

11/18/2012 0 11/28/2012 0

RM 47 R
11/18/2012 0 11/28/2012 0

RM 50 R

11/17/2012 0 11/28/2012 0

RM 55 R
11/28/2012 11/18/2012 0 0

RM 65.8 L

11/17/2012 0 11/25/2012 0

RM 87 L
11/18/2012 0 11/26/2012 0

RM 122 R

11/26/2012 11/16/2012 0 0

RM 137 L
11/17/2012 0 11/27/2012 0

RM 194 L

11/18/2012 0 11/27/2012 0

RM 225 R
Substantial Loss (3 sites)

11/17/2012 0 11/28/2012

RM 51 L

-1
11/18/2012 0 11/26/2012 -1

RM 91 L

11/18/2012 0 11/27/2012 -1

RM 173 L
Comparison of Response Among 4 Controlled 

Floods: 1996, 2004, 2008, 2012

• 15 sites with cameras present during all 4 events

– In each year, a few sites did better, a few not as well, 

nothing stands out, too few sites to make any general 

conclusions

• 26 sites with cameras present in 2008 and 2012

– Sandbar larger in 2012: 4 sites, 3 above RM 32

– Sandbar smaller in 2012: 7 sites

– Sandbar about the same in 2012: 15 sites
Observations at Sites Not Monitored 

by Remote Cameras
11/29/2012

11/29/2012

10/8/2011

4/4/2009

RM 35L, Nautiloid Camp
Grand Canyon River Guides 

Adopt-a-Beach Site

Shinumo

Wash Camp

Apr 2008 RM 29.4 L

Oct 2010 Dec 2012
Clear Creek 

Camp

May 2008 RM 84.6 R

Nov 2011 Dec 2012

Grand Canyon River Guides 

Adopt-a-Beach Site
Zoroaster 

Camp

Mar 2008 RM 84.9 L

Apr 2011 Dec 2012

Grand Canyon River Guides 

Adopt-a-Beach Site
Stone Creek 

Camp

Mar 2008 RM 132.4 R

Sep 2011 Dec 2012

Grand Canyon River Guides 

Adopt-a-Beach Site
Sandbar Surveys

• October 2012 – surveyed all 44 long-term 

sandbar monitoring sites between Lees Ferry 

and Diamond Creek on annual monitoring trip

• November-December 2012 – surveyed 6 of 

those sites on post-flood NPS trip
October 2012 (pre-HFE) Sandbar 

Volume in Marble Canyon

Number of Sites 

Compared

Number Larger Number Smaller

Bar volume 

compared to 1990 16 6 10

Bar volume 

compared to 2008 

pre-flood 31 12 19

Bar volume 

compared to 2008 

post-flood 31 2 29
Sandbars in Marble Canyon before 2012 

Controlled Flood

• Some increase between October 2011 and October 2012

• Both 2011 and 2012 are low relative to early 1990’s and post-flood surveys
Sandbar Surveys Following Nov. 2012 

Controlled Flood

RM 9 RM 30 RM 44 RM 47 RM 65 RM 68

Classification 

from photo 

analysis

Gain Gain no

noticeable 

change

no

noticeable 

change

Large gain gain

Surveyed change 

in average bar 

elevation

68 cm 93 cm - 3 cm 6 cm 114 cm 32 cm

• Analysis from remote cameras consistent with 

surveyed changes in sandbars
Sandbar Surveys Following 2012 controlled 

flood compared to other controlled floods

Bar Elevation

Relative to 

2012 post-HFE*

RM 9 RM 30 RM 44 RM 47 RM 65 RM 68

2012 0 (1) 0 (2) 0 (4) 0 (3) 0 (2) 0 (2)

2008 -0.03 (2) -0.64 (4) 0.55 (1) 0.37 (2) 0.22 (1) 0.22 (1)

2004 na -0.13 (3) 0.39 (2) na -0.28 (3) na

1996 na 0.08 (1) 0.02 (3) 0.49 (1) -0.83 (4) -0.30 (3)

* Ranking for the 4 floods in parentheses

• Magnitude of bar building during 2012 flood is comparable to 

previous floods

• Very few sites to compare, but nothing stands out as 

dramatically different
0

10,000

20,000

30,000

40,000

50,000

-10 -5 0 5 10 15 20

1996

2004

2008

2012

DISCHARGE, IN CUBIC FEET PER SECOND

TIME, IN DAYS RELATIVE TO DEPARTURE FROM NORMAL DAM OPERATIONS

What is the effect of changing the hydrograph 

of the high flow?
Sandbar Shape – RM 30

1996 post-HFE 2012 post-HFE 2004 post-HFE 2008 post-HFE

>8,000 cfs

>25,000 cfs

>8,000 cfs

>25,000 cfs

>8,000 cfs

>25,000 cfs

>8,000 cfs

>25,000 cfs

• Bar volume largest in 1996, area above 8,000 cfs stage largest in 2012
Sandbar Shape – RM 30

• Slope from bar crest to 8,000 cfs level less steep than other floods

• For 3 sites with post-flood surveys and large reattachment bars, the area of newly 

deposited bar above the 8,000 cfs stage with slope less than 8 deg. was larger in 

2012 than previous floods
Conclusions

• 2012 flood resulted in sandbar building, as 

observed in previous controlled floods

• Bar building not as widespread as 2008

– But likely stronger than 2008 in upper Marble Canyon

• Effect of slower rate of flood recession

– Not a dramatically different response

– May have resulted in bars that are less steep in a few 

locations

– Need more observations, numerical modeling, and 

probably controlled laboratory experiments to better 

understand the effect of hydrograph shape
Work in FY13 and FY14

• In work plan

– Monitoring in-channel sand storage

– Mapping of bed texture with application for fish and 

aquatic habitat

– Annual sandbar surveys (44 sites)

– Analysis of overflights to monitor sandbars throughout 

Grand Canyon

– Geomorphic attributes of campsites

– Continue work on modeling eddy sandbars

– Interactions between sediment on bed and in suspension

• Pilot monitoring

– Measurements of sandbar topography from remote 

cameras