ABSTRACT:

Steady low reservoir releases increase downstream primary and aquatic invertebrate (bugs) production. These releases also reduce hydropeaking value, raise costs for hydropower customers, and reduce funds to maintain infrastructure and repay loans. This study quantifies the win-lose tradeoff between hydropeaking value and days per month of steady low releases at Glen Canyon Dam, Arizona. We estimate win-lose tradeoffs for monthly release volumes of 0.71 to 0.95 million acre-feet from March to October 2018 and 0 to 31 days. Conservative estimates indicate that steady low releases on eight weekend days per summer month in 2018 reduced monthly hydropeaking value by $430,000 to $850,000. We used results to design a financial instrument that gives ecosystem managers a budget to choose days of steady low releases and compensate hydropower producers for lost value. One option to reduce costs is shifting days of steady low releases to spring/fall months. Next steps include discussing the proposed instrument with more U.S. Federal agencies, conducting more flow experiments, and monitoring how timing and more steady low flow days per month affect bug production. Managers may extend to other experimental releases that mobilize sediment, build sand bars, or disadvantage non-native fish.

##This resource contains the following items:
+ README.md - Markdown file with documentation for this resource including directions to reproduce results in the manuscript
+ GCD_BugFlowExperiment-main - Folder with sub-folders that contain the data, models, and code to reproduce figures, tables, and results in the manuscript.
+ Final_Draft_JHI_2025.pdf -- PDF document with the up-to-date manuscript for the work.
+ Rind and Rosenberg_2025_Supplementary.pdf --PDF document with supplementary information for the manuscript.
+ Rosenberg-BugsPayForSteadyFlows-AprilAMP.pptx - Power point presentation with overview of work presented at April 12/13, 2023 meeting of the Technical Work Group (TWG) of Glen Canyon Dam Adaptive Management Program (GCD-AMP).
+ KeyFeedbackFromTechnicalWorkGroup-April12-2023.docx - Key feedback from presentation to GCD-AMP Technical Work Group on April 12, 2023.

## Reproducibility: Bhupinderjeet Singh and Philip Moffatt at Washington State University, USA downloaded the materials and reproduced all figures and tables.

## Updates: We encourage users to visit our GitHub repository (https://github.com/moazzamalirind/GCD_BugFlowExperiment.git) for the latest updates and extended project details.

ABSTRACT:

Steady low reservoir releases increase downstream primary and aquatic invertebrate (bugs) production. These releases also reduce hydropeaking value, raise costs for hydropower customers, and reduce funds to maintain infrastructure and repay loans. This study quantifies the win-lose tradeoff between hydropeaking value and days per month of steady low releases at Glen Canyon Dam, Arizona. We estimate win-lose tradeoffs for monthly release volumes of 0.71 to 0.95 million acre-feet from March to October 2018 and 0 to 31 days. Conservative estimates indicate that steady low releases on eight weekend days per summer month in 2018 reduced monthly hydropeaking value by $430,000 to $850,000. We used results to design a financial instrument that gives ecosystem managers a budget to choose days of steady low releases and compensate hydropower producers for lost value. One option to reduce costs is shifting days of steady low releases to spring/fall months. Next steps include discussing the proposed instrument with more U.S. Federal agencies, conducting more flow experiments, and monitoring how timing and more steady low flow days per month affect bug production. Managers may extend to other experimental releases that mobilize sediment, build sand bars, or disadvantage non-native fish.

##This resource contains the following items:
+ README.md - Markdown file with documentation for this resource including directions to reproduce results in the manuscript
+ GCD_BugFlowExperiment-main - Folder with sub-folders that contain the data, models, and code to reproduce figures, tables, and results in the manuscript.
+ Final_Draft_JHI_2025.pdf -- PDF document with the up-to-date manuscript for the work.
+ Rind and Rosenberg_2025_Supplementary.pdf --PDF document with supplementary information for the manuscript.
+ Rosenberg-BugsPayForSteadyFlows-AprilAMP.pptx - Power point presentation with overview of work presented at April 12/13, 2023 meeting of the Technical Work Group (TWG) of Glen Canyon Dam Adaptive Management Program (GCD-AMP).
+ KeyFeedbackFromTechnicalWorkGroup-April12-2023.docx - Key feedback from presentation to GCD-AMP Technical Work Group on April 12, 2023.

## Reproducibility: Bhupinderjeet Singh and Philip Moffatt at Washington State University, USA downloaded the materials and reproduced all figures and tables.

## Updates: We encourage users to visit our GitHub repository (https://github.com/moazzamalirind/GCD_BugFlowExperiment.git) for the latest updates and extended project details.