84044 REL 66

2007-393-00 EXP PROTECT RESTORE SE WA/NE OR WATERSDHED HABITAT 25

5/1/2025

4/30/2026

175. Produce Design

Work Element Usage Report

M: 175 - Poley Allen Post Project Control Survey

The project site is located at a privately owned irrigation diversion structure that crosses the Lostine River approximately 1 mile south of the town of Lostine, Oregon. More specifically, the project site is located at river mile 4.8 on the Lostine River and generally includes the mainstem Lostine River and the Poley-Allen irrigation diversion structure and intake.

The project design development focused on mitigating fish passage limitations associated with the mechanical manipulation of the channel and providing irrigation water to the water right holders. The design development also included side-channel habitat improvements with LWM structures. The design engineer developed the proposed actions collaboratively with the landowners and the NPT and identified the roughened channel as the preferred alternative for providing fish passage while maintaining the necessary head for irrigation delivery. The proposed actions involve construction of a roughened channel, modification of the existing concrete sill and removal of the existing abutment on the right channel bank. Boulders will be placed within the roughened channel for hydraulic complexity and roughness. Irrigation water will continue to be collected in the existing concrete point of delivery located upstream of the grade-controlling roughened channel. The engineer anticipates streambed material deposition within the forebay due to static channel grade. To manage sediment deposition within the entrance forebay, they included a sediment management pipe with a manually operated valve that discharges downstream within the roughened channel. The outcome of this project will maximize year-round fish passage for all life history stages of Bull Trout, steelhead, and Chinook Salmon, while maintaining access to irrigation water for current water rights holders.

The project was completed in the fall of 2023 and has been successful. An as-built survey was also conducted upon project completion. As the channel adjusts over time, irrigators and landowners have been pleased and the hopes of the project remaining successful high. However, in the event something should adjust and impact the delivery of irrigation water, a survey may be warranted to document any adjustment or changes. This survey would entail a longitudinal survey and measurements at key project component locations for comparison and documentation.

A survey would be completed by spring of 2026 if and only if a noticeable change in channel or irrigation function were to exist or persist over the irrigation season (April-August of 2025). The survey would include a longitudinal profile as well as measurements at key control points derived during the as-built survey in order to detect change, if any. If no change is detected by NPT staff or project associated landowners or irrigators, no survey would be necessary and the action would become null and void. This WE will be cancelled.

Survey would be conducted by a sub-contractor under supervision and review of NPT staff.

$6,000

1.15%

05/01/2025

04/30/2026

Planned

[Unassigned]

[Unassigned]

Finite