Colorado River in Grand Canyon behaves like a 

pipe – a pipe with a very rough boundary

There are pockets of fine sediment, primarily sand, 

that occur in isolated pockets and as thin ribbons. 

Some of the very fine sand is blown by winds to 

higher elevation.

The 

physical 

system 
When fine sediment enters the river 

from tributaries (primarily the Paria

River), the sand and mud is initially 

deposited on the channel bottom 

and at low elevation 
This sand and mud is quickly 

transported downstream. The mud 

is transported most quickly and the 

sand that remains on the bed 

becomes coarser.
30-mile

61-mile

Grand Canyon gage

(87-mile)

above Diamond Creek gage

(225-mile)

Glen Canyon Dam

Lake

Mead

Upstream boundary of

Grand Canyon 

National Park

Paria River

166-mile

Little Colorado 

River

Lees Ferry

gage

(0-mile)

Where we do it A comprehensive fine sediment measurement program is 

in place to track inputs and exports
30-mile

61-mile

Grand Canyon gage

(87-mile)

above Diamond Creek gage

(225-mile)

Glen Canyon Dam

Lake

Mead

Upstream boundary of

Grand Canyon 

National Park

Paria River

166-mile

Little Colorado 

River

Lees Ferry

gage

(0-mile)

Where we do it The focus of river management is on the fine sediment 

mass balance of Upper Marble Canyon 
USGS AZ WSC sampling near the PARIA RIVER AT LEES FERRY, AZ 

gage during a flood on the Paria River

US D-74 sampler suspended from 

fixed reel on bridge

ISCO 6712 automatic pump 

sampler

INTAKE location for the ISCO 6712 

pump sampler
Location of the 30-mile sampling 

tagline

Boat deployment for the US D-77 

bag-type and US D-96 suspendedsediment samplers

Manned, motorized, boat equipped for the collection of 

suspended–sediment data at tagline locations along the 

Colorado River in Grand Canyon, Arizona. Photo taken at the 

location of the river mile tagline.
Instrumentation and site appearance at the 30-mile sediment-transport station. A, 

configuration of instruments. The rock wall behind the instruments is used to 

camouflage the station. B, Site appearance from river level. View is downstream. Site 

is concealed behind the rock wall.

A.

B.

ISCO Pump samplers

Radio-modem 

antennas

Satellite 

antenna

Site shown 

in photo A
Mount for the 2-MHz Acoustic doppler Profiler (ADP) at the 30-

mile sediment-monitoring station. Photograph shows the 

camouflaged mount and the radio modem antenna.

ADP mount

Radio-modem antenna

Underwater photo of ADP instrument head

(USGS diver for scale)
Measured discharge of the Paria River at Lees Ferry

July 1 to October 23, 2012

sand

silt and clay

533,000

688,000

Paria River at Lees Ferry

water
The stream flow that determines input of 

sediment

The stream flow that determines export 

of sediment from upper Marble Canyon
sand

silt and clay

Sediment transport at RM30

86,000

95,000
Fine sediment mass balance in 

upper Marble Canyon

Export of sand past RM30

468,000

685,000
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

Between July 1 and October 1 ...

Between 468,000 

and 685,000 metric 

tons accumulated 

in upper Marble 

Canyon

86,000 – 95,000 metric 

tons were transported 

past the RM 30 gage

533,000 – 680,000 metric tons entered 

Colorado River from the Paria River

Little to no fine 

sediment 

accumulated in 

lower Marble 

Canyon

Long-term average sand load for July, 

August, September is 725,000 tons

Mass balance prior to 2004 and 2008 HFEs

July 1 to November 2004: 275,000 – 491,000 metric tons

December 2004 – March 2008: 567,000 – 1,823,000 metric tons
Recommended High Flow Experiment for 

November 2012

Upramp rate is slower 

than 1996 and faster than 

2004/2008. Efficiently 

uses water and does not 

unnecessarily stress 

measurement equipment 

downstream. 

Peak flow to sustain high 

deposition rates and allow 

comparison with previous HFEs

Slow recession rate to 

improve deposition 

characteristics in eddies

Efficient use of 

water
Recommended High Flow Experiment for 

November 2012
October 02 - 19 I. Riparian vegetation Pre-HFE riparian vegetation survey in Marble and Grand Canyons

October 02 - 19 A. Campsite/sandbar monitoring NAU/USGS fall campsite/sandbar monitoring

October mid-month F. Rainbow trout early life stage study Electrofishing survey of age-0 rainbow trout in Glen Canyon

October 15 - 19

F. Rainbow trout monitoring in Glen 

Canyon

AZGF electrofishing survey of adult rainbow trout and other nonnative 

fish in Glen Canyon

October 20-29 F. Rainbow trout natal origins

Rainbow trout tagging - effort to PIT tag 8,000-10,000 fish in Glen 

Canyon as part of an ongoing mark-recapture study

November before 11/18 B. Sediment transport

Pre-HFE sampling of sediment transport at 60 mile, Grand Canyon (~87 

mile), and National Canyon (167 mile)

November before 11/18 F. Foodbase monitoring

Pre-HFE sampling of invetebrate drift, primary productivity, and 

benthos at Lees Ferry and Diamond Creek

November 18 - 24 B. Sediment transport

HFE sampling of sediment transport at 60 mile, Grand Canyon (~87 

mile), and National Canyon (167 mile)

November 18 - 24 F. Foodbase monitoring

HFE sampling of invetebrate drift at Lees Ferry, RM61, and Diamond 

Creek

November late Nov B. Sediment transport

Post-HFE sampling of sediment transport at 60 mile, Grand Canyon 

(~87 mile), and National Canyon (167 mile)

November late Nov F. Foodbase monitoring

Post-HFE sampling of invetebrate drift, primary productivity, and 

benthos at Lees Ferry and Diamond Creek

December 3 - 7

H. Rainbow trout population 

management

Post-HFE electrofishing surveys and mark-recapture effort to monitor 

any fish response to HFE

Late Nov or early 

January ?

A. Sandbar and sediment storage 

dynamics

Post-HFE retrieval of memory cards from remote cameras for sandbar 

time series photos

December ? F. Rainbow trout early life stage study Rainbow trout redd counts in Glen Canyon

January ?

F. Rainbow trout natal origins/juvenile 

chub monitoring

Quarterly electrofishing surveys and mark-recapture effort to monitor 

rainbow trout abundance and movement/quarterly monitoring of 

juvenile humpback chub near the Little Colorado River confluence

January ? F. Rainbow trout early life stage study Rainbow trout redd counts in Glen Canyon

GCMRC Science Activities associated with HFE