Lake Fork Feeder Canal Diversion Structure & Water Conveyance System

Introduction

The Moon Lake Water Users Association (MLWUA) in Roosevelt, UT, uses the water from the Yellowstone and Lake Fork Rivers for irrigation and other needs but have recently found their current water supply insufficient. The Lake fork Feeder Diversion Structure and Water Conveyance System aims to increase the available water supply by transferring water from the Lake Fork Riverto the Yellowstone River to allow water to be diverted at the existing MLWUA Canal on the Yellowstone River. In order to accomplish this task a new diversion and canal system need to be implemented. This project focuses on the water diversion structure and canal design to move water from the Lake Fork River to the Yellowstone Feeder Canal.

Requirements

Each piece of the project must accomplish the following:

• Diversion Structure.
  • Pass large flood events
  • Be manually activated and deactivated
  • Maintain a constant head in varying flow conditions
• Canal Path
  • Passively move water to required location
  • Meet with the Yellowstone River upstream of Yellowstone Feeder Canal
• Canal Type
  • Minimize cost of materials and construction
  • Leave water uncovered
  • Minimize water lost to seepage and evaporation

Alternatives

For each piece of the project there are the following alternatives:

• Diversion Structure.
  • Passive Weir Structure
  • Manual Gate Structure
• Canal Path
  • A straight course from beginning to end
  • A curved path that follows the contours of the terrain

• Canal Type
  • A lined canal
  • An unlined canal
  • A piped system

Alternative Evaluations

Diversion Structure

The diversion structure for this project needs to be able to move water when needed, but also be able to pass flood events without issue. The best system to do this is to have a passive Ogee weir combined with two radial gates; one gate to back up flow with the ogee weir and another to control when flow enters the canal. The radial gates can be locally produced for an affordable rate.

Canal Path

The Canal needs to be able to move water from an upstream location of the Lake Fork River to the Yellowstone river but needs to be upstream of the existing Yellowstone Feeder Canal. In order to avoid any kinds of pumping, the canal will follow the curvature of the landscape. To keep the flow velocity from getting too big, the bottom slope of the canal will be supplemented by several drop structures along its course, and where the canal empties into the Yellowstone River a spillway will contain the flow as it enters a very steep grade.

Canal Type

The Canal needs to be able to efficiently move water from the Lake Fork River to the Yellowstone River while minimizing losses due to evaporation and infiltration. The canal must also have minimal construction costs. Initially it seems like a piped system would be ideal, but due to the diversion’s location on Ute Tribal land and the tribe’s beliefs about covering water, any type of covered system will not meet the requirements for building on the land. A lined canal is the next best choice, since the sandy soil in the area is prone to infiltration.

Final Design

After evaluating all the options, the following options were selected. Each option finds the best balance between affordability, performance, and constructability.

• Diversion Structure: A Combination Ogee Weir And Radial Gate Structure.
  • Allows manual control for when water is needed.
  • Ogee weir maintains a constant head.
• Canal Path: A Contoured, Elevation-controlled Path.
  • Uses elevation change to move water without pumping.
  • Drop structures help alleviate steep slope.
  • Requires a spillway near the end of canal.
• Canal Type: A Concrete Lined Canal.
  • Concrete liner is easy to construct and prevents infiltration.
  • Concrete is resilient enough to not be damaged by wildlife crossing the canal.

Acknowledgements

Our team would like to thank the following:

• Eric Major with Jones and DeMille Engineering
• Dex Winterton with The MLWUA
• Brian Crookston of USU