6/27/2011
 

Update on Sand Mass Balance 

with Modeling 

GCDAMP TWG Meeting 

June 29, 2011 

Paul Grams, David Topping, Scott Wright 

U.S. Department of the Interior 

U.S. Geological Survey 

USGS Sediment Flux Monitoring Program in 

Grand Canyon 

Mainstem flow 

Mainstem flow and sediment 

Tributary flow and sediment 

Sediment budget reach 

RM 0-30 – upper Marble Canyon
 

RM 30-61 – lower Marble Canyon
 

RM 61-87 – eastern Grand Canyon
 

RM 87-166 – central Grand Canyon
 

RM 166-225 – western Grand Canyon
 

David Topping

Ronald Griffiths

Thomas Sabol

Nicholas Voichick

Karen Vanaman

1 
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6/27/2011
 

-1.5 

-1.0 

-0.5 

0.0 

0.5 

1.0 

1.5 

2.0 

2.5 

3.0 

0 

10,000 

20,000 

30,000 

40,000 

50,000 

POST-2008 HFE MASS-BALANCE SAND BUDGET 

BETWEEN RIVER-MILES 0 AND 30 

2008 2009 2010 2011 

WATER DISCHARGE 

MASS-BALANCE UNCERTAINTY ENVELOPE 

SAND MASS IN REACH RELATIVE TO AFTER

RECESSION OF MARCH 2008 HFE (million metric tons)

DISCHARGE AT

RIVER-MILE 30 (ft3 /s) 

Sand budget INDETERMINATE for period.

Note dam releases increased to 22,500 cfs 

on 5-14-11, after end of accounting period 

5-2-11 

CALENDAR YEAR 

Preliminary results subject to review and revision 

Model Predicted Mass Balance Sand Budget from end of 2008 

HFE to May 2, 2011Between River Miles 0 and 30 

Model tends to track with the lower bound 

of measurements 

Preliminary results subject to review and revision 

Measured upper bound 

Measured lower bound 

2 
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6/27/2011
 

Model Predicted Mass Balance Sand Budget from end of 2008 

HFE to September 30, 2011Between River Miles 0 and 30 

Predicts ~ 1 million tons export 

from May 2 to October 1 

Preliminary results subject to review and revision 

May 2 measured lower 

bound 

Assumes NO Paria River sand input 

-1.5 

-1.0 

-0.5 

0.0 

0.5 

1.0 

1.5 

2.0 

2.5 

3.0 

0 

10,000 

20,000 

30,000 

40,000 

50,000 

POST-2008 HFE MASS-BALANCE SAND BUDGET 

BETWEEN RIVER-MILES 30 AND 61 

2008 2009 2010 2011 

WATER DISCHARGE 

MASS-BALANCE UNCERTAINTY ENVELOPE 

SAND MASS IN REACH RELATIVE TO AFTER

RECESSION OF MARCH 2008 HFE (million metric tons)

DISCHARGE AT

RIVER-MILE 61 (ft3 /s)

Sand budget INDETERMINATE for period.

After dam releases increased in January 2011,

the 2010 Paria River sand exported from upper

Marble Canyon stopped accumulating in this reach. 

Lower Marble Canyon is behaving

like a sand pipe under these higher releases. 

5-2-11 

CALENDAR YEAR 

Preliminary results subject to review and revision 

3 
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6/27/2011
 

Model Predicted Mass Balance Sand Budget from end of 2008 

HFE to May 2, 2011Between River Miles 30 and 61 

Model tends to track with the upper bound 

of measurements 

Preliminary results subject to review and revision 

Measured upper bound 

Measured lower bound 

Model Predicted Mass Balance Sand Budget from end of 2008 

HFE to September 30, 2011Between River Miles 0 and 30 

Predicts ~ 0.6 million tons export 

from May 2 to October 1 

Preliminary results subject to review and revision 

May 2 measured upper 

bound 

Assumes NO Paria River sand input 

4 
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6/27/2011
 

-1.5 

-1.0 

-0.5 

0.0 

0.5 

1.0 

1.5 

2.0 

2.5 

3.0 

0 

10,000 

20,000 

30,000 

40,000 

50,000 

POST-2008 HFE MASS-BALANCE SAND BUDGET 

BETWEEN RIVER-MILES 61 AND 87 

2008 2009 2010 2011 

WATER DISCHARGE 

MASS-BALANCE UNCERTAINTY ENVELOPE 

SAND MASS IN REACH RELATIVE TO AFTER

RECESSION OF MARCH 2008 HFE (million metric tons)

DISCHARGE AT

RIVER-MILE 87 (ft3/s)

Sand budget NEGATIVE for period.

Except for during floods on the LCR,

dam releases >13,000 cfs have been scouring

sand from eastern Grand Canyon. 

5-2-11 

CALENDAR YEAR 

Preliminary results subject to review and revision 

Model Predicted Mass Balance Sand Budget from end of 2008 

HFE to May 2, 2011Between River Miles 61 and 87 

Model tends to track with the upper bound 

of measurements 

Preliminary results subject to review and revision 

Measured upper bound 

Measured lower bound 

5 
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6/27/2011
 

Model Predicted Mass Balance Sand Budget from end of 2008 

HFE to September 30, 2011Between River Miles 0 and 30 

Predicts ~ 0.6 million tons export 

from May 2 to October 1 

Preliminary results subject to review and revision 

May 2 measured upper 

bound 

Assumes NO Paria River sand input 

-1.5 

-1.0 

-0.5 

0.0 

0.5 

1.0 

1.5 

2.0 

2.5 

3.0 

0 

10,000 

20,000 

30,000 

40,000 

50,000 

POST-2008 HFE MASS-BALANCE SAND BUDGET 

BETWEEN RIVER-MILES 87 AND 225 

2008 2009 2010 2011 

WATER DISCHARGE 

MASS-BALANCE UNCERTAINTY ENVELOPE 

SAND MASS IN REACH RELATIVE TO AFTER

RECESSION OF MARCH 2008 HFE (million metric tons)

DISCHARGE AT 

RIVER-MILE 225 (ft3 /s)

Sand budget INDETERMINATE for period.

Central Grand Canyon stopped accumulating

sand eroded from upstream reaches

when dam releases were 

increased in January 2011.

 Like lower Marble Canyon, most of

Grand Canyon is behaving like a sand pipe under

these higher releases. 

5-2-11 

CALENDAR YEAR 

Preliminary results subject to review and revision 

6 
   

     

   

   

   

   

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6/27/2011
 

Mainstem flow 

Mainstem flow and sediment 

Tributary flow and sediment 

Sediment budget reach 

RM 0-30 – upper Marble Canyon 

RM 30-61 – lower Marble Canyon 

RM 61-87 – eastern Grand Canyon 

RM 87-166 – central Grand Canyon 

RM 166-225 – western Grand Canyon Sand routing

model not yet

developed for

segments

downstream from

Grand Canyon

gage (RM 87)

USGS Sediment Flux Monitoring Program in 

Grand Canyon 

No sand 

routing 

model 

Current sand 

routing model 

Comparison of May 2011 status with status 

leading up to 2004 and 2008 high flows (review 

of information presented at May AMWG meeting) 

All values in million metric tons. 

Preliminary results subject to review and revision 

Reach July 1, 2004 

to start of 

2004 HFE 

End of 

2004 HFE 

to start of 

2008 HFE 

End of 2008 

HFE to Jan. 7, 

2011 

End of 2008 HFE 

to May 2, 2011 

RM 0 to 30 0.4 ± 0.1 1.2 ± 0.6 1.4 ± 0.4 +0.25 ± 0.35 

RM 30 to 61 0.1 ± 0.05 0.5 ± 0.3 -0.05 ± 0.15 -0.10 ± 0.10 

RM 61 to 87 0.0 ± 0.05 0.8 ± 0.7 -0.35 ± 0.35 -0.90 ± 0.50 

RM 87 to 225 0.2 ± 0.1 0.9 ± 0.4 0.35 ± 0.35 +0.40 ± 0.50 

Green = definitely positive 

Orange = indeterminate, maybe positive 

Yellow = indeterminate, maybe negative 

Red = definitely negative 

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6/27/2011
 

Summary
 

 The relatively high volume dam releases of winter-spring summer 

2011 (~ 17,000  24,000 cfs) do not permit sand retention 

 Measured sand export from January 1, 2011 to May 2, 2011:

 ~0.7 million tons loss from upper Marble Canyon (RM 0 to 30) 

 ~0.15 million tons loss from lower Marble Canyon (RM 30 to 61) 

 ~1.05 million tons loss from eastern Grand Canyon (RM 61 to 87) 

 ~0.2 million tons loss from central and western Grand Canyon (RM 87 to 

225)

 Model-predicted sand export from May 2, 2011 to October 1, 2011:

 ~1.0 million tons loss from upper Marble Canyon (RM 0 to 30) 

 ~0.6 million tons loss from lower Marble Canyon (RM 30 to 61) 

 ~0.6 million tons loss from eastern Grand Canyon (RM 61 to 87) 

 No model prediction for central and western Grand Canyon (RM 87 to 225) 

 Sand is moving out of upper Marble Canyon by deflation (the “new” 

pile of sand delivered by Paria in Fall 2010, is shrinking and being

transported through the downstream reaches in suspension, not 

moving downstream as a “wave” on the bed) 

Preliminary results subject to review and revision 

8