Grand Canyon Sediment 

Augmentation Study

Tim Randle, P.E.

Manager, Sedimentation and River 

Hydraulics Group, Denver, Colorado
Sediment Augmentation Objectives

• Seasonally increase turbidity to 

provide cover for native fish.

• Annually increase sand supply to 

build larger sandbars, in 

conjunction with beach-building 

flows.

RECLAMATION
Sediment Augmentation Plan

• Increase turbidity by continuously 

supplying silt- or clay-sized sediments 

from May through December to produce 

suspended sediment concentrations of 

500 ppm (3 million tons per season).

• Annually supply 1 million tons of sand 

to Grand Canyon.

RECLAMATION
Study Team

• Reclamation Engineers

– Tim Randle (overall guidance)

– Joe Lyons (team leader)

– Ron Ferrari (Lake Powell survey)

– Jim Yahnke (water quality)

– Fred Tan (pipeline design)

– Rick Christensen (sediment dredging)

– Richard Fehr (pumping plant design)

– Lisa Gamuciello (electrical power)

– Larry Rossi (electrical controls)

– Jerry Zander (cost estimation)
Study Team (continued)

• National Park Service

– Norm Henderson (plan formulation)
Types of Sediment

Augmentation Alternatives

• Alternative sediment sources

• Alternative points of delivery

• Alternative delivery methods

RECLAMATION
Alternative Sediment Sources

• Lake Powell Deltas

• Lake Mead Delta

• Other Terrestrial Site

RECLAMATION
Lake Powell Deltas

Colorado Riv

San Juan Riv

Dirty Devil River

Escalante River

Navajo Cany

Glen Canyon Dam

RECLAMATION
Sediment Source near Glen Canyon

RECLAMATION

Glen Canyon Dam

Navajo 

Canyon is the closest 

sediment source 

to Glen Canyon.
Navajo Canyon Delta

RECLAMATION
Navajo Canyon Survey

RECLAMATION

December 2004
RECLAMATION

Navajo Canyon Profile

3110.0

3210.0

3310.0

3410.0

3510.0

3610.0

3710.0

0.00 5.00 10.00 15.00 20.00 25.00

Distance (miles)

Elevation (feet)

2004

1986

Original

R- 421

R- 422

R- 424

R- 425

R- 427

R- 429

R- 430

Average thickness 

11 m (36 ft)
Navajo Canyon Sedimentation

• Maximum sedimentation volume of 

40 million m3(30,000 acre-feet ) 

since 1963

• Maximum sediment mass of 40 

million tons 

• Average annual sedimentation rate of 

1 million tons per year

RECLAMATION
Navajo Canyon Sediment Sustainability

RECLAMATION

0

20

40

60

80

100

120

140

160

180

200

1,000,000 1,500,000 2,000,000 2,500,000 3,000,000 3,500,000 4,000,000

Annual Sediment Augmentation Rate (tons per year)

Life Expectancy (years)
Sediment Size and Quality 

of One Delta Sample

• 57 % silt and clay

• 43 % sand

– 30 % very fine sand

– 13 % medium sand

• Angular quartz particles have high potential 

for abrasion of pipes, valves, and pumps

• Sample was analyzed for 39 elements

– no contaminants were found

RECLAMATION
Alternative Points of Delivery

RECLAMATION

Below Glen 

Canyon Dam

Lees Ferry

Other locations in Glen Canyon?
Sediment Discharge Locations

• Below Glen Canyon Dam

– Sand: continuous year-round discharge

– Silt and clay: continuous, seasonal 

discharge

• Lees Ferry

– Sand: stock pile and discharge before 

beach-building flow

– Silt and clay: continuous, seasonal 

discharge

RECLAMATION
Alternative Delivery Methods

• Barge and truck 

• Sediment slurry pipeline

RECLAMATION
Barge and Truck Alternative

Eliminated

• Excessive barge traffic on Lake Powell

– Barge size: 30 m x 10 m (100 ft x 30 ft)

– 37 barge trips per day for sand

– 135 barge trips per day for silt and clay

• Excessive truck traffic on highway 

between Page and Lees Ferry

– 130 truck trips per day for sand

– 500 truck trips per day for silt and clay

RECLAMATION
Sediment Slurry Pipeline Alignments

• Overland from Navajo Canyon 

• Submerged in Lake Powell

RECLAMATION
Overland Pipeline Alignment

Eliminated

• Steep bedrock topography of 

Navajo Canyon has more than 

300 m (1,000 ft) of vertical rise 

• No roads cross this pristine area 

• A floating pipeline would still be 

required to deliver sediment from 

the dredging operation to the 

overland pipeline

RECLAMATION
Lake Powell Slurry Pipeline 

Alignment

RECLAMATION
RECLAMATION

Sediment Slurry Pipeline Alignment 
RECLAMATION

Sediment 

Slurry 

Pipeline: 

Navajo 

Canyon to 

Lees Ferry 
Sediment Slurry Pipeline Lengths 

• Navajo Canyon to Glen Canyon Dam

– 28.2 km (17.5 miles) of submerged pipeline

– 13.8 km (8.6 miles) of buried pipeline

• Navajo Canyon to Lees Ferry

– 28.2 km (17.5 miles) of submerged pipeline

– 79.3 km (49.3 miles) of buried pipeline

RECLAMATION
RECLAMATION

Submerged Pipelines

Buoy

Silt/clay pipelines

Sediments

Anchors

Mooring cables

Sand pipelines

Pulleys and 

counterweights

Submerged powerline
Sand Slurry Pipeline Dimensions 

• Three, 12-inch (0.30 m), pipes

– HDPE (High Density Polyethylene)

• Total flow rate of 4.4 ft3/s (0.12 m3/s)

• 15 % sand concentration

• Annual water volume of 3,000 acre-feet 

per year (4 million m3/yr)

RECLAMATION
Silt/clay Slurry Pipeline Dimensions 

• Three, 24-inch (0.61 m), pipes

– HDPE (High Density Polyethylene)

• Total flow rate of 27 ft3/s (0.76 m3/s)

• 20 % silt/clay concentration

• Annual water volume of 13,000 acre-feet 

per year (16 million m3/yr)

RECLAMATION
Land-based Pumping Plants 

RECLAMATION

Building size: 

• 9 m (30 ft) wide 

• 18 m (60 ft) long

• 3 m (10 ft) high
Floating Pumping Plants 

RECLAMATION

Modular barge size: 

• 3 m (10 ft) wide 

• 12 m (40 ft) long

• 2 m ( 7 ft) deep
Sediment Slurry Pumping Plants 

• Navajo Canyon to Glen Canyon Dam

– 3 floating pumping plants

– 4 land-based pumping plants

• Navajo Canyon to Lees Ferry

– 3 floating pumping plants

– 17 land-based pumping plants

RECLAMATION
Navajo Canyon Dredging Operation

RECLAMATION

Near continuous operation 

of clamshell dredge
RECLAMATION

Sediment 

Slurry 

Pipeline

Navajo 

Canyon to 

Lees Ferry 
Sand Storage near Lees Ferry 

• Two basins would alternatively be used 

to settle the sand from the slurry 

pipeline.

• Each basin would be 275 m by 75 m 

(900 feet by 250 feet) and would fill in 

about one month.

RECLAMATION
Sand Storage near Lees Ferry 

• Bulldozers, loaders, and trucks would 

remove the sand from each basin. 

• 1 million tons of sand would be stored 

near the Colorado River.

• Sand storage volume

– 190 m by 190 m (630 ft by 630 ft)

– 15 m (50 ft) high

• Pushed into river by bulldozers (D-10)

RECLAMATION
Costs 

• Appraisal-level cost estimates are in 

progress?

RECLAMATION
Conclusions 

• A sediment slurry pipeline is technically 

feasible.

• No environmental problems have been 

identified at this time.

• Attempts have been made to avoid 

cultural resources impacts.

• Augmentation of fine sediment should 

be considered with selective withdrawal.

RECLAMATION
Next Steps

• Cost estimates are in progress

• Finalize the report

• If there is stakeholder interest:

– More sampling and testing of sediments

– Feasibility design to Congress

– Congressional authorization

– Final design

– Construction bids

RECLAMATION