Updates on 2014 HFE, 2015 Paria River inputs, and 

2015 mass balance for Marble Canyon

Ronald E. Griffiths*

David J. Topping

Paul E. Grams

Robert B. Tusso

*rgriffiths@usgs.gov

USGS GCMRC
Introduction

Overview of 2014 HFE

• Initial conditions

• Downstream tour – where did the sand end up?

• How did the beaches respond?

2015 Paria River sand inputs

• How much sand have we received to date?

• Improvements in processing samples and updating the website

• How does this year compare with previous years?

2015 Marble Canyon mass balance

• How much sand has been retained from the Paria

• Comparisons with previous years
2014 HFE overview

3 Paria River floods of 

approximately

2000 cfs, 1 flood of 

approximately 6000 cfs

1.2 million metric tons of 

sand input from 

July 1, 2014 through 

October 20, 2014

2014 Paria River sand inputs

Preliminary results, subject to review 

and revision – do not cite
2014 HFE overview 2014 HFE upper Marble Canyon

Upper Marble Canyon

RM 0 – RM 30

Preliminary results, subject to review 

and revision – do not cite
2014 HFE overview 2014 HFE lower Marble Canyon

Lower Marble Canyon

RM 30 – RM 61

Preliminary results, subject to review 

and revision – do not cite
2014 HFE overview 2014 HFE western Grand Canyon

Western Grand Canyon

RM 61 – RM 87

Preliminary results, subject to review 

and revision – do not cite
2014 HFE overview 2014 HFE east central Grand Canyon

East Central Grand Canyon

RM 87 – RM 166

Preliminary results, subject to review 

and revision – do not cite
2014 HFE overview

West Central Grand Canyon

RM 166 – RM 225

2014 HFE west central Grand Canyon

Preliminary results, subject to review 

and revision – do not cite
2014 HFE overview 2014 HFE western Grand Canyon

Western Grand Canyon

and the Lake Mead Delta

> RM 225

Preliminary results, subject to review 

and revision – do not cite
2014 HFE overview

Overall change in sand mass in the Colorado

River between RM0 and RM225 (Lees Ferry

to Diamond Creek) during July 1, 2014 – January 1, 2015 

was:

+0.59+0.92 million metric tons; sand deposited in lower 

Marble Canyon and east central Grand Canyon, sand 

evacuated from western Grand Canyon and west central 

Grand Canyon

Overall change in sand mass in the Colorado

River below RM225 (below Diamond Creek) during July 1, 

2014 – January 1, 2015 was:

+1.4+0.1 million metric tons

Preliminary results, subject to review 

and revision – do not cite
2014 HFE overview

Sandbar size immediately 

after HFE, in relation to 

pre-flood size:

• 24 sites (58%) larger

• 13 sites (29%) no 

change

• 5 sites (14%) smaller

November 8, 2014

November 17, 2014

Photos at www.gcmrc.gov/sandbar/

119 R

Preliminary results, subject to review and revision – do not cite
2014 HFE overview

Preliminary results, subject to review and revision – do not cite

compared to sandbar size pre-HFE
2014 HFE overview

Response to HFE Protocol Since 2012

Each of the HFEs 

in the past 3 years 

has resulted in 

sandbar 

deposition

– They 

continue to 

erode in 

following 6 

to 12 months

Photos at www.gcmrc.gov/sandbar/

2012 HFE 2013 HFE 2014 HFE

Preliminary results, subject to review 

and revision – do not cite
2015 Paria River sand inputs

Zero bias value for 2015 Paria sand 

inputs is approximately 1.1 million 

metric tons, almost an additional 

400,000 metric tons in June

Preliminary results, subject to review 

and revision – do not cite
2015 Paria River sand inputs

Flood event on 8/12/2015 is an 

example of “hyperconcentrated

flow”, this flood input over 1/4 of the 

total 2015 Paria sand input

All samples through 8/27/2015 have 

been processed by the laboratory, 

most recent processed sample is 

from 9/17/2015

The processed samples represent 

80% of the total number of Paria

samples collected this year compared 

with 52% of the samples at this time 

last yearPreliminary results, subject to review 

and revision – do not cite
2015 Paria River sand inputs

Laboratory procedures have been changed over the last 

year to increase efficiency and expedite Paria samples

• Backlog of other samples have been reduced

• Dynamic staffing of the laboratory increases the 

number of samples processed during key periods

• Representative samples are selected to process within 

days of a flood to rapidly increase the accuracy of the 

Paria sand loads

• During the HFE accounting period, Paria samples are 

given precedent over other samples
2015 Paria River sand inputs

Comparison of 2015 zero bias value Paria sand inputs with 

previous years; accounting period 7/1 through 10/20

• 2015 Paria sand input: 1.1 million metric tons

• 2014 Paria sand input: 1.2 million metric tons – HFE

• 2013 Paria sand input: 1.8 million metric tons – HFE

• 2012 Paria sand input: 0.7 million metric tons – HFE

• 2011 Paria sand input: 0.1 million metric tons

Preliminary results, subject to review 

and revision – do not cite
2015 Marble Canyon mass balance

Upper Marble Canyon from 7/1/2015 

through 9/28/2015 (most recent 

download date)

• Uncertainty bound straddles zero

• Approximately 450,000 metric tons of 

sand was exported during the 

equalization flows of July

• Some of the sand exported was the 

result of June Paria floods increasing 

the sand supply

Preliminary results, subject to review 

and revision – do not cite
2015 Marble Canyon mass balance

Lower Marble Canyon from 7/1/2015 

through 9/28/2015 

• Zero bias value is +590,000 metric 

tons

• Much of the sand exported from 

upper Marble Canyon was deposited 

in lower Marble Canyon

• During this period, the sand mass 

balance of Marble Canyon was 

+650,000 +290,000 metric tons 

Preliminary results, subject to review 

and revision – do not cite
2015 Marble Canyon mass balance

Comparison of upper Marble Canyon with previous years

Preliminary results, subject to review and revision – do not cite
2015 Marble Canyon mass balance

Comparison of lower Marble Canyon with previous years

Preliminary results, subject to review and revision – do not cite
2015 Marble Canyon mass balance

Comparison of Marble Canyon zero bias sand mass balance 

with previous years 7/1 through 9/28

• 2015: +650,000 metric tons

 

• 2014: +1,200,000 metric tons

• 2013: +1,900,000 metric tons

• 2012: +720,000 metric tons

• 2011: -580,000 metric tons – equalization flows

Preliminary results, subject to review and revision – do not cite
2015 Marble Canyon mass balance

Sand was evacuated from upper Marble Canyon during July 

and early August flows– likely from retreating sandbars and 

June Paria inputs

Sand deposited in lower Marble Canyon – in storage 

underwater or below the 20k CFS flow level

The total change in sand mass for Marble Canyon from 

7/1/2015 to 9/28/2015 is +650,000 metric tons plus a likely 

additional +300,000 metric tons input from the Paria River 

since 9/28 (next update will occur on 11/9)

Preliminary results, subject to review and revision – do not cite
Questions?