Project A: Streamflow, Water Quality, and Sediment 

Transport and Budgeting in the Colorado River Ecosystem 

Project A collects the physical data that directly link dam operations to all 

resources in the downstream Colorado River; data inform 10 LTEMP goals 

• Element 1: Stream gaging 

– Stage 

– Discharge 

• Element 2: Water quality 

– Water temperature 

– Salinity (specific conductance) 

– Turbidity 

– Dissolved Oxygen 

• Element 3: Sediment transport and budgeting 

– Suspended- and bed-sediment data 

– Sediment loads (silt and clay loads and sand loads) 

– User-interactive sand budgets in 6 reaches from Lees Ferry to Lake Mead 

• All elements 

– Database and website (currently UNSUPPORTED) 
 

 

 

 

 

 

 

Evaluation of LTEMP sand management 

David J. Topping1 

Paul E. Grams1 

Ronald E. Griffiths1 

Matt Kaplinski1 

Joel A. Unema2 

David J. Dean1 

Katie A. Chapman1 

1U.S. Geological Survey 2U.S. Geological Survey 

Southwest Biological Science Center Arizona Water Science Center 

Grand Canyon Monitoring and Research Center 

The information in several of these slides is preliminary and is subject to revision. It is being 

provided to meet the need for timely best science. The information is provided on the 

condition that neither the U.S. Geological Survey nor the U.S. Government shall be held liable 

for any damages resulting from the authorized or unauthorized use of the information. 
Upper Marble Canyon 

West-Central Grand Canyon 

Remote-sensing and 

channel-mapping data 

can also inform here 
 

Eastern Grand Canyon? Lower Marble Canyon 

East-Central Grand Canyon 
 

HFE-Protocol/LTEMP Period 

Upper Marble Canyon 

7/1/2012 – 9/30/2023 

2012-07-01 

POSITIVE 

Data from USGS (2024a, b) 

POSITIVE 

Possibly sustainable 
 

HFE-Protocol/LTEMP Period 

Lower Marble Canyon 

POSITIVE 

2012-07-01 

7/1/2012 – 9/30/2023 

POSITIVE(?) 

Insufficient HFE magnitude/duration or intervening flows too high 

Data from USGS (2024a, b) 
 

 

HFE-Protocol/LTEMP Period 

Eastern Grand Canyon 

INDETERMINATE 

Large LCR 

inputs 2012-07-01 

7/1/2012 – 9/30/2023 

POSITIVE(?) 

Intervening flows likely too high (SAVED BY THE LCR) 

Data from USGS (2024a, b) 
 

HFE-Protocol/LTEMP Period 

East-Central Grand Canyon 

POSITIVE 

2012-07-01 

7/1/2012 – 8/30/2023 

POSITIVE(?) 

Insufficient HFE magnitude/duration or intervening flows too high 

Data from USGS (2024a, b) 
 

HFE-Protocol/LTEMP Period 

West-Central Grand Canyon 

7/1/2012 – 8/30/2023 

2012-07-01 

POSITIVE 

Data from USGS (2024a, b) 

POSITIVE 

Possibly sustainable 
Project A References • Barnhardt, W.A., Kayen, R., Rubin, D., and Minasian, D.L., 2001, The internal structure of sand bars on the 

Colorado River, Grand Canyon, as determined by ground-penetrating radar: U.S. Geological Survey OpenFile Report 2001-425, 74 p. https://doi.org/10.3133/ofr01425 

• Chapman, K.A., Best, R.J., Smith, M.E., Mueller, E.R., Grams, P.E., and Parnell, R.A., 2020, Estimating the 

contribution of tributary sand inputs to controlled flood deposits for sandbar restoration using elemental 

tracers, Colorado River, Grand Canyon National Park, Arizona: Geological Society of America Bulletin, v. 

133, p. 1141–1156. https://doi.org/10.1130/B35642.1 

• Hazel, J.E., Jr., Kaplinski, M.A., Hamill, D., Buscombe, D., Mueller, E.R., Ross, R.P., Kohl, K., and Grams, P.E., 

2022, Multi-decadal sandbar response to flow management downstream from a large dam—The Glen 

Canyon Dam on the Colorado River in Marble and Grand Canyons, Arizona: U.S. Geological Survey 

Professional Paper 1873, 104 p., https://doi.org/10.3133/pp1873 

• Topping, D.J., Grams, P.E., Griffiths, R.E., Dean, D.J., Wright, S.A., and Unema, J.A., 2021, Self-limitation of 

sand storage in a bedrock-canyon river arising from the interaction of flow and grain size: Journal of 

Geophysical Research: Earth Surface, v. 126, e2020JF005565. https://doi.org/10.1029/2020JF005565 

• U.S. Geological Survey, 2024a, Discharge, sediment, and water quality monitoring, Grand Canyon 

Monitoring and Research Center: accessed on January 11, 2024, at 

http://www.gcmrc.gov/discharge_qw_sediment/ 

• U.S. Geological Survey, 2024b, Grand Canyon sandbar monitoring, Grand Canyon Monitoring and Research 

Center: accessed on January 11, 2024, at http://www.usgs.gov/apps/sandbar/