Possible Fall 2017 HFE Planning

Katrina Grantz

Reclamation

Scott VanderKooi

GCMRC

TWG presentation

October 12, 2017
1. Planning and Budgeting Component

 Annual resource status assessment

 Annual Agency Reporting

 GCDAMP Budget and Work Plan Process

2. Modeling Component (is there enough sediment?)

3. Decision and Implementation Component

 Review Modeling Component

 Review Status of Resources

 Consultation with agencies and tribes, AMWG 

input

 Staff Recommendation/ HFE Leadership Team 

Recommendation

 DOI decision

LTEMP HFE Process
Fall 2017 HFE planning steps taken

• Jan 2017 TWG meeting: discussed possible experiments for 

upcoming year – fall HFE, extended duration fall HFE

• July and August – coordinated with management agencies to 

determine best dates for possible HFE

• Aug 31: update to TWG on HFE status and process

• Sept 1: notification to GCDAMP stakeholders of possible date for 

HFE: Nov 6th 

• Sept 21:update to AMWG (not enough sediment to trigger HFE)

• Sept 27, Oct 4: HFE Tech team discuss sediment conditions, ops, 

HFE process, other resources (including brown trout)

• Oct 5: notification of possible HFE to parties of PA, follow up Oct 11

• Oct 10: notification to GCDAMP stakeholders, HFE tech team, DOI 

leadership of no HFE

• Oct 11: HFE tech team discuss lessons learned, close the planning 

process
Flow and Sediment 

conditions

from the GCMRC

web page as of 

Oct 10, 2017

http://cida.usgs.gov/gcmrc/

discharge_qw_sediment/stations/GCDAMP Preliminary Data – Do not cite or distribute

~ 285,000 

metric tons
Sand Budget Model Results

10-10-2017

Modeling 

suggested there 

COULD be 

enough 

sediment to 

support a 1-hr 

36, 500cfs 

HFE... need to 

ground truth 

this with field 

data. 
Potential High Flow Experiment: 

Status of Resources

Scott VanderKooi

USGS Grand Canyon Monitoring and Research Center

Technical Work Group Webinar

October 12, 2017
Paria River Sand Inputs

https://www.gcmrc.gov/discharge_qw_sediment/station/GCDAMP/09382000

(Preliminary Data from GCMRC. 2017. Do Not Cite.)

~ 285,000 metric tons of sand 

inputs through 10/10/2017.
Sand Mass Balance –

Upper Marble Canyon

2017-10-10

https://www.gcmrc.gov/discharge_qw_sediment/reach/GCDAMP/09380000/09383050

Inputs primarily from two 

events since July 1, 2017. 

(Preliminary Data from GCMRC. 2017. Do Not Cite.)
Sand Mass Balance –

Lower Marble Canyon

https://www.gcmrc.gov/discharge_qw_sediment/reach/GCDAMP/09383050/09383100

(Preliminary Data from GCMRC. 2017. Do Not Cite.) 2017-10-10

Sum of point estimates for 

Upper and Lower Marble 

Canyon reaches is 

~ +73,000 metric tons, 

lower bound is ~ -35,000 

metric tons.
• Sediment conditions do not support a 2017 Fall HFE 

• No HFE Technical Team recommendation

• No HFE Technical Team report

• No HFE Leadership Team recommendation

• No DOI decision

2017 HFE Planning Outcomes and Summary
• Went well: 

• Setting possible HFE date early 

• Informal meetings with tech team early

• Ideas for improvement:

• Reclamaiton send letters to PA parties at same time 

we notify GCDAMP of possible HFE date

• Reclamation have sand budget model recalibrated 

over winter

• GCRMC evaluate early in HFE planning window 

what size HFE would be meaningful (e.g., 1 hr?)

• Brown trout – understand risk of an HFE early in the 

planning window to help fame discussions

• Other?

2017 HFE Lessons Learned
Questions?