This project has been on the priority list for several years. The primary need for this project is to reduce habitat fragmentation for migratory cutthroat trout in the Weber River and diversify the spatial distribution of spawning habitat. Dalton Creek is one of eight small direct tributaries that flow into the lower Weber River near Peterson, Utah. Although small (1-3 miles in length), these tributary streams play an important role in supporting critical spawning and rearing habitats for the fluvial (migratory) Bonneville cutthroat trout that occur within this reach of the Weber River. These cutthroat trout are not only highly-sought-after by anglers, but also represent an ecologically important conservation population with a unique migratory life history. Unfortunately most of the spawning habitat in these tributaries has been rendered inaccessible; blocked by road crossings and irrigation diversions. Over the past 5 years TU, UDWR, the US Fish and Wildlife Service and other partners have worked collaboratively to improve fish passage on all of these tributaries. Examples of these projects include culvert replacement on Jacobs Creek, a step-pool complex to secure passage around a driveway bridge on Gordon Creek, and a vertical slot fish ladder on Strawberry Creek under I-84. Complimentary to the conservation actions taken in the tributaries, the project partners have also been engaged in reconnection efforts on the mainstem of the Weber River, including fish passage and screening on the Lower Weber River Diversion and relicensing on the Pacificorp Hydropower Facility. Aided by a new and expanding dataset, with over 2000 Bonneville cutthroat trout in the Weber River tagged with PIT tags and a PIT tag antenna array distributed among the spawning tributaries, the UDWR has identified Dalton Creek as a potentially important spawning tributary for BCT in this reach of the Weber River, based on the number of fish detected traveling over PIT tag antennas. This recent information indicates that Dalton Creek has the potential to play an important role in contributing spawning habitat to this population. Much like every other tributary in this section of the Weber River, a road culvert, approximately 400 feet upstream of its terminus represents a significant challenge to fish migrations associated with the access road for the Gateway Canal. This specific culvert is associated with a road that is operated by the Weber Basin Water Conservancy District . The culvert is perched vertically, with over a 4 ft drop, with another vertical drop at the upstream end of the culvert, rendering this culvert impassable and blocking approximately 3 miles of spawning habitat. This specific project proposal is intended to develop a design for the culvert modification or replacement. Due to the large vertical drop, flashy hydrology in Dalton Creek and close proximity to infrastructure, project partners have agreed that we need to develop an understanding of the scale and scope of the construction project and to ensure that critical infrastructure, including a building and a canal, which provides much of the drinking water to Davis and Weber Counties is not impacted.

The objectives of the overall project are to make this road crossing passable so migratory BCT can access spawning habitat.

This project addresses the risk of habitat fragmentation within the Weber River. A 2013 basinwide barrier assessment identified almost 400 fish migration barriers across the entire Weber River watershed. The approach taken by TU and the UDWR has been to focus on several key areas in the watershed and prioritize restoration and reconnection actions within those areas, to effectively address the basinwide challenge. This reach of the Lower Weber River and its tributaries is a priority because of the presence of migratory BCT and Bluehead sucker strongholds. The Gateway Canal provides water for much of the Ogden-Clearfield area and the road associated with this culvert causes this barrier. Because of the proximal nature of the canal to this road crossing and it's association with building structures, we see a need to ensure that a solid engineering design and construction plan are in place.

BCT Conservation Agreement and Strategy Identified habitat fragmentation as a primary threat to BCT persistence. Reconnecting habitat for populations with unique life histories is a primary objective in the Northern and Bear River GMU's. Weber River Watershed Plan Assessing and identifying fish passage barriers is a key strategy within the 2014 watershed plan, specifically as the assessments lead towards prioritized habitat reconnection projects in key areas. This passage project meets those criteria and supports reconnection actions in the plan.

This project adds to the population resiliency of BCT in the event that a fire wipes out a major tributary important to this fishery. Creating spatially redundant subpopulations and spawning habitats reduces the risk of entirely losing a population when a wildfire occurs.

This project does not directly affect water quality or quantity. Although Dalton Creek has irrigation diversions in the middle watershed that affect water quantity, we have not approached water users regarding leases or efficiency. This project improves the availability of this clean, cold water to an economically and ecologically important cutthroat trout population.

As with all aquatic projects we anticipate applying for stream alteration permits, which will incorporate cultural resources. However, the uncertainty around the area of disturbance requires us to rely upon the design so we can develop a construction plan and establish the scope of a needed cultural resources.

Our primary methods will be to replace the culvert with a 10 foot diameter culvert. We will need to build 1-2 small step pools below the culvert to ensure passablity for all live stages of trout. Construction will be completed by the Weber Basin Water Conservancy District maintenance crew with construction support by the WBWCD Engineer.

An effective monitoring program has been in place on this reach of the Weber River since 2011 using the PIT tag antenna array described above. This monitoring indicates that Dalton Creek is potentially an important spawning tributary to the fluvial BCT living in the Weber River. We will continue to monitor this stream and others. After project completion, PIT tag antennas will be placed upstream and downstream of this culvert to track use and success of passage in the reconstructed or replaced culvert. We also hope to develop an understanding of which tributaries are the most important to the BCT in the Weber River, to help guide potential water leasing opportunities.

Trout Unlimited Utah Division of Wildlife Resources Weber Basin Water Conservancy District US Fish and Wildlife Service National Fish and Wildlife Foundation Dee Foundation

This project is complimentary to other proposed or completed fish passage actions that project partners have engaged in throughout neighboring tributaries such as Strawberry Creek, Gordon Creek and Jacobs Creek. The overall intent of these actions is to reconnect a geographically diverse array of tributaries for BCT spawning to improve the resiliency of this important fluvial population. The tributary actions also compliment our actions and opportunities within the Weber River mainstem, including instream flow leases, reconstruction of the lower Weber River diversion with fish passage, and a collaborative FERC hydropower relicensing project on PacifiCorp's power facility.

Greater geographic spawning habitat diversity promotes sustainable use of the cutthroat trout population by providing an important and consistent source of available spawning habitat as well as consistent supply of juvenile fish to help sustain the cutthroat trout population levels in the Weber River.

06/01/2019

10/31/2021

2022

We used a combination of both drone imagery and GPS survey equipment to develop a 3D model of the area in proximity to the culvert. With this information we were able to understand the slope of the stream, appropriate size of a new culvert and number of drops needed to pass fish. Initial engineering was completed by Weber Basin Water Conservancy Staff with additional guidance and final engineering by RiverRestoration.org. Weber Basin Water Conservancy provided the materials and all of the equipment/staff time for construction.

The original culvert (6 ft diameter) was undersized for the amount of runoff that Dalton Creek produces. As a result, every couple of years, Dalton Creek would overwhelm and overtop the culvert and erode the creek downstream. Initially we considered just developing a step-pool complex below the culvert to allow passage, but after several design iterations all of the partners concluded that it would be most beneficial for all parties if we replace the culvert entirely, lower the elevation by one foot, and then step Dalton Creek down from the outlet of the culvert. We replaced the 6-foot culvert with an 8x10-foot elliptical culvert which matches the dimensions of the N. Morgan Valley Drive culvert, located just upstream. The new culvert is constructed with baffles to facilitate passage. We constructed 9 vertical plunge pools with boulders and footers downstream of the culvert. We attempted to space the drops as evenly as possible but had to contend with a natural gas pipeline, 2 crude oil pipelines and a fiber optic line which were buried in the area.

There are other opportunities for fish passage improvement upstream in Dalton Creek, as well as opportunities to attempt to lease flow to sustain perennial flow in this reach of Dalton Creek. The vertical plunge pools should be evaluated for effectiveness.