U.S. Department of the Interior

U.S. Geological Survey

Update on Project N Activities 

Including a Discussion of Hydropower 

Improvement Flows

Lucas S. Bair, U.S. Geological Survey, Southwest Biological Science Center, Grand Canyon 

Monitoring and Research Center

Glen Canyon Dam Adaptive Management Program

Technical Work Group Meeting

October 12-13, 2022

U. S. Department of Interior

U.S. Geological Survey
Hydropower and Energy Goal

• Maintain or increase Glen Canyon Dam (GCD) electric 

energy generation, load following capability, and 

ramp rate capability, and minimize emissions and 

costs to the greatest extent practicable, consistent 

with improvement and long-term sustainability of 

downstream resources.

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Project N: Hydropower 

Monitoring and Research

• Project N will identify, coordinate, and 

collaborate with external partners on 

monitoring and research opportunities 

associated with operational experiments at 

GCD designed to meet hydropower and energy 

resource objectives...

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4
Total 2024 WECC variable operations cost by 

generation type when natural gas is $4/mbtu Average Cost per MwH

Preliminary data, do not cite

5
Total 2024 WECC variable operations cost by 

generation type when natural gas is $4/mbtu Average Cost per MwH

Preliminary data, do not cite

6
Total 2024 WECC variable operations and emissions 

cost by generation type when natural gas is $4/mbtu Average Cost per MwH

Preliminary data, do not cite

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-5 to -10,000 tons

-10,000 to -20,000 tons

-20,000 to -30,000 tons

-30,000 to -40,000 tons

-40,000 to -100,000 tons

No Change / <5 tons

Preliminary data, do not cite 8

Change in annual 2024 SO2 emissions with ‘flat 

flows’ at GCD and natural gas at $4/mbtu
Waldo, S., Deemer, B.R., Bair, L.S. and Beaulieu, J.J., 2021. Greenhouse gas emissions from an arid

-zone 

reservoir and their environmental policy significance: Results from existing global models and an exploratory 

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dataset. Environmental Science & Policy, 120, pp.53-62.
Trout Management Flows

U.S. Department of Interior, 2016, Glen Canyon Dam Long-term Experimental and Management Plan final 

Environmental Impact Statement (LTEMP FEIS): U.S. Department of the Interior, Bureau of Reclamation, Upper 

Colorado Region, National Park Service, Intermountain Region, online, http://ltempeis.anl.gov/documents/final-eis/.

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Hydropower Modeling

• We developed a constrained optimization problem 

to assess the short run economic costs of 

environmental constraints on hydropower operation.

• The objective of the hydropower model is to 

maximize the economic value of hydropower over 

the planning horizon subject to monthly volumes, 

reservoir levels, and operational constraints. 

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Hydropower Optimization Results

Revenue

Without TMFs

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Revenue

With TMFs

Preliminary data, do not cite
Optimal Trout Management Flow Policy

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Marble Canyon rainbow trout abundance

12500

10625

8750

6875

5000

Adult humpback chub abundance 12500

10625

8750

6875

5000

12500

10625

8750

6875

5000

Preliminary data, do not cite
Secretary’s Designee’s Requests

• The Secretary’s Designee’s August 2022 

Requests – How to Optimize High-Flow 

Experiments in the Current Environment

• Project Element J.1. Predictive Models for 

Adaptive Management

• Project N: Hydropower Monitoring and 

Research

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Project J.1: Predictive Models for 

Adaptive Management

• Sub-element: sandbars 

– The primary objective of this sub-element is to 

use the physically based sandbar model of 

individual bar response, using flow, stage, 

sediment concentration, and sediment grain size, 

to predict changes in sandbar size, while 

considering the economic costs to hydropower, 

over various future flow and sediment scenarios.

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16

Mueller, E. R., & Grams, P. E. (2021). A morphodynamic model to evaluate long-term sandbar 

rebuilding using controlled floods in the Grand Canyon. Geophysical Research Letters, 48, 

e2021GL093007. https://doi.org/10.1029/2021GL093007

November 2022 33,100 cfs 48-hr High Flow Experiment (HFE)

Morphodynamic Model
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Photo Credit: Amy S. Martin