SUMMARY OF SAND-BAR DATA 

Hydrology

–

Has varied from “dry” t

back to “dry” Full UB Hydrologic 

Bar Responses

–

Largest responses fo

most dramatic operations (BHBF R

Long-Term Response

–

Decline in all 

Marble Canyon, but less so at highGrand Canyon

Cause & Effect

–

Limited sediment su

median flow increase of 75%
TW

G UP

D

ATE -

S

and Bar Area

s 

“Syste

m

-

Wi

d

e

”

In F

l

u

ctuatin

g

Z

ones of E

d

d

i

e

s

1990-2001(NAU Da

t

a

)

10,00015,00020,00025,00030,00035,00040,000

Sand Bar Area (m2)

at 30 Long-Term Monitoring Sites 

Year

1990 1991 1992 1993 1994 1995 19

10,00015,00020,00025,00030,00035,00040,000

Sand Bar Volume (m3)

at 30 Long-Term Monitoring Sites

Year

1996 BHBF 

1990 1991 1992 1993 1994 1995 19

Marble C. (n=12)Grand C. (n=18)

Marble C. (n=12)Grand C. (n=18)
TWG UPDATE - Sand Bar Area a

“Saddle Camp”1990-2001(NAU Data)

0

2,0004,0006,0008,000

10,000

Sand Bar Area (m

2

)

Year

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 20

1996 BHBF

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2

Fluctuating Zone

High Elevation

0

2,0004,0006,0008,000

10,000

Sand BarVolume (m

3

)

Year

1996 BHBF

High ElevationFluctuating ZoneHigh ElevationFluctuating Zone
TWG UPDATE - Sand Bar Area a

Grapevine Camp1990-2001(NAU Data)

0

500

1,0001,5002,0002,500

Sand Bar Area (m

2

)

Year

0

500

1,0001,5002,0002,500

Sand Bar Volume (m

3

)

Year

1990 1991 1992 1993 1994 1995 1996 1997 1998 199

1996 BHBF HMF's

1996 BHBF

HMF's

1990 1991 1992 1993 1994 1995 1996 1997 1998 199

1993 LCR

Flood

High ElevationFluctuating ZoneHigh ElevationFluctuating Zone
DOWNSTREAM FROM NAN

1890. The pre-dam river was lined with expansive sandbars. The banks were mostly barren of vegetation up to the old high-water line (Stanton). 

1991. The sanddisappeared, lecobble bars. Rencroached on banks.
THE CAMPING BEACH DOW

FROM TAPEATS CRE

1952 (Kent Frost). Everyone would want to camp here now.

1995. The bebriefly after t
CHANGES AT DEER CREEK 

1923. Beach present,falls fans out (LaRue)

1972. Riparian vechokes channel mbeach, new rocks 

1940. Falls fans out wider, large beach present, rocks shifted(Goldwater)
SUMMARY OF SAND BALANC

(WY 1999-2001)

Basin Hydrology

–

Has varied from “dry” t

back to “dry” Full UB Hydrologic Cycle 

Paria

Inputs

–

Sand equal to annual averag

Sand Supply

–

Largest responses forced by 

operations (BHBF Response)

Long-Term Response

–

No evidence of chan

accumulation throughout river system, beddy storage responds to mainstem hydr

Cause & Effect

–

Declining sediment supply 

caused by compressed flood frequency, liand fine grain size of sand from downstr
Sand Inputs (1999 – 200

“TAKE-HOMES” ON SAND BALAN

(1999-2001)

Basin Hydrology

–

Dry Now! Chance for C

and Restoration of Bars – Let’s Water the 

Sand Inputs

–

Paria River Continues its Do

Sand Supply

–

Currently winnowed, last in

were below average for sand from all sou

Long-Term Response

–

No evidence of chan

accumulation, but export reduced during average ROD operations in WY 2001-200

Cause & Effect

–

Declining sediment supply 

caused by compressed flood frequency, liand fine grain size of sand from downstr
Revisiting BETA Con

What is it?A New Sediment-Supply Monitoring Paramete

(Concentration and Grain-Size in SuspensiBack-Calculate the Grain-Size of Sediment 

What does it mean?Quickly Tells How Enriched or Depleted the BWho Cares about more sediment informatiIt Could End Up Telling Us What We Need to 

Cost and Effort in Real Time...

High-Flow Treatments and Spill Volumes?How Long Before Channel-Bed Is “Cleaned” 

Sand-Bar Restoration or for Cleaning Grav

SUMMARY OF BETA PLO

(1999-2001)

Sand Inputs – How significantly is the chan

enriched and over what period following inputs?

Sand Supply – When are we there? When a

When should we Water the Canyon?

Long-Term Monitoring – How does curren

enrichment or depletion of sand in channrelative to previous periods of pre- or poenrichment conditions throughout a give

Use w/ LISST Support – Should be able to s

Time” basis for evaluating sand-supply dthroughout the ecosystem’s “active-trans
Grand Canyon Gage (Bu

3⁄4 Extremely Reliable Flow Record3⁄4 Just US from SS Cross-Section3⁄4 Flow & Sediment Record (1925-2002)3⁄4 Well-Mixed Flow Zone (turbulent)3⁄4 Historically S

ignificant Test S

ite for 

USGS Sediment Samplers

3⁄4 Ideal Setting for LISST Deployment 

and Testing

3⁄4 GCMRC Intensive Sediment 

Monitoring Program Provides Abundant Verification Data for New Alternative Methods
Grand Canyon Gag

(2001 LISST Fixed-Depth Te

3⁄4 24-Hour Test Duration

(over 1-Diurnal Cycle)

3⁄4 13 –

Cableway (D-77)

Samples Obtained

3⁄4 720 –

LISST-100B Samples

(averaging 16 measurements every 2-minutes)

3⁄4 Flow Range

–

9,000 to 

17,000 cfs (typical summer)

3⁄4 Highly Mixed Cross Section

w/ Mostly Quartz Sand

3⁄4 Bedrock-Controlled

Channel w/o Flood Plains
RESULTS - SAND CONCENT

2468

10

02040608010121416

0 5 10 15 20 25

LISST POINT VALUES AT UPPER GAGE 

CROSS-SECTIONALLY INTEGRATED VALUES MEASURECABLEWAY WITH D-77 BAG SAMPLER

LISST SAND CONCENTRATION (μl/l)

HOURS AFTER START OF TEST

 (LISST CONCENTRATIONS) x14.0 mg/μl = (MEASURED CONCENTRATIO
RESULTS - SILT & CLAY CONCE

2468

10

0511

0 5 10 15 20 25

LISST POINT VALUES AT UPPER GAGE 

CROSS-SECTIONALLY INTEGRATED VALUES MEASURECABLEWAY WITH D-77 BAG SAMPLER

LISST SILT&CLAY CONCENTRATION (μl/l)

HOURS AFTER START OF TEST

 (LISST CONCENTRATIONS) x12.9 mg/μl = (MEASURED CONCENTRAT

ERROR?
RESULTS - MEDIAN GRAIN-SIZ

0.080.090.100.110.120.130.14

0 5 10 15 20 25

LISST POINT VALUES AT UPPER GAGE 

CROSS-SECTIONALLY INTEGRATED VALUES MEASURECABLEWAY WITH D-77 BAG SAMPLER

LISST SUSPENDED-SAND D50 (mm)

HOURS AFTER START OF TEST

 (LISST D50) x1.19 = ( CABLEWAY MEASURED D50) 
THANKS AGAIN FOR 

ATTENTION . . 

Pray for Ra