ALTA HARRIS CREEK: A BOISE RIVER SIDE CHANNEL IMPROVES TROUT HABITAT

Photos over time show how the stream has taken shape and as water has infiltrated the channel. Check out the photos from the culvert crossing as well as along the existing wetland at the west end of the stream. The volunteer planting efforts have begun to pay off as the vegetation along the banks has become established. Some site visits have also happened, including a visit Bureau of Reclamation Commissioner John Keys on June 23, 2005.

The Boise River is an enormous asset for the Treasure Valley, supplying water for irrigation and other uses, providing recreation and development opportunities, aesthetic beauty and habitat for fish and wildlife. The river flows through a major city (190,000 residents, and 400,000 people in the greater metropolitan area) that has naturally spawning rainbow and brown trout. The section of the river at Harris Ranch has "quality" fishing regulations, a nearly 85 percent catch and release rate, and the most healthy and robust aquatic species community in the lower Boise River.

Habitat studies of the Boise River however, show that the river lacks suitable spawning and rearing habitat. Restoring side channels to the river is recommended because few such channels remain. Harris Ranch represents the last area with the greatest potential for significant side channel development.

Three large storage reservoirs located in the basin have a combined storage capacity of nearly one million-acre feet. Reservoirs have been operated primarily to satisfy flood control and irrigation requirements with little concern for the fishery. Dams also prevent movement of suitable spawning gravel from the headwater streams to the Boise River through town. These projects prevent natural processes of streambed movement of larger and smaller gravel, channel formation, and other ecological processes of a river environment.

The Boise River is designated a "water quality limited" segment under Section 303 of the Clean Water Act. The water quality assessment (TMDL) of the Boise River included a finding that lack of spawning habitat is one issue needing attention.

Harris Ranch is an important partner on this project. They have incorporated the side channel into their master plan and they have donated considerable staff time and expertise.

The National Fish and Wildlife Foundation has awarded a challenge grant to the Ted Trueblood Chapter in support of planning and design for this project.

Riverstone Community School is located just a nine iron away from the side channel project area. The school will provide support and volunteer help on some of the restoration work.

The Idaho Department of Environmental Quality is providing important financial support for this project.

Funding for this project has been provided by the Edwards Mother Earth Foundation.

The Land Trust of the Treasure Valley is a cooperator on this project. The Land Trust of the Treasure Valley promotes and coordinates activities in Southwest Idaho that conserve open space and provide alternatives to development for the benefit of public and private landowners alike.

Idaho Fish and Game is providing fisheries expertise and construction assistance to the initial phase of the side channel restoration effort.

The University of Idaho Center for Ecohydraulics Research has provided assistance for this project through field surveys and special studies.

A new side channel would benefit the Boise River by providing quality trout spawning, rearing, and pools for winter holding habitats. The project involves a partnership of Trout Unlimited, Harris Ranch, Idaho Fish and Game, Land Trust of the Treasure Valley and the Bureau of Reclamation involved in the design and construction of the side channel. A Monitoring Plan has been developed with the goal of assessing the changes in riparian vegetation and fish populations once the stream is constructed. Design of the project has been informed by an aquatic model simulation of the stream.

This project is designated as a high priority project in the City of Boise's Boise River Management and Master Plan, and will be the most significant action implemented to date under this plan. Trout Unlimited participated on the Steering Committee that helped the city write this plan. Boise City is noted for its nationally recognized Boise River Greenbelt, a nationally recognized river and parkland protection effort that was initiated over 30 years ago. The city also has adopted a progressive Boise River Ordinance that regulates development along the river.

A partnership approach of conservation interests, private landowners, and government to address urban fisheries habitat needs is necessary across the west. Many urban areas on the west coast of the United States are now addressing habitat needs for anadromous pacific salmon species that have been placed on the endangered species list. Further inland, projects like this one are promoting conservation and protection of resident and/or native salmonids.

Lessons learned from this project will lead to additional side channel and riparian/wetland habitat projects at downstream areas where habitat restoration and connectivity can occur along the Boise River. Other likely candidates include Cottonwood Creek, Loggers Creek, and side channels through the city owned Warm Springs Golf Course.

Construction of the first phase of this project started in March 2005 near the downstream end at Eckert Bridge on the north side of the Boise River. The channel is now excavated in two sections. The lower section is near the river and groundwater infiltrated the channel in April. The upper channel is getting water from drainage at the upstream end. (view plan drawings here). Construction is being provided by the Idaho Department of Fish and Game and their experienced construction crew. The excavated material was spread on site away from the stream channel and existing wetlands.

Once the excavated stream was extended upstream to the surface and groundwater sources the infiltrating water began to irrigate the stream bottom and banks. Water has been impounded by leaving certain locations of the channel plugged.
These water sources provide little actual flow and our objective at this initial phase is not a flowing stream but rather the water necessary to establish vegetation along the banks of the stream and create riparian habitat. During the rest of 2005 we have started to transplant willow and plant other vegetation such as sedges to accelerate the growth of vegetation.

During the winter months we expect that the trickle of water from the artesian well and the excavated trench will for the most part sink into the ground along the course of the stream. As we move into the spring months and the water table rises we expect that the stream will have water in it for most of its length if not the entire constructed reach. We base this estimate on the groundwater monitoring information gathered on site since early 2002.

With the higher water table in spring and summer months we expect the banks along the excavated stream will exhibit vigorous growth of riparian vegetation. This rapid colonization will be accelerated by the placement of vegetation in late winter and early spring. The site exhibits rapid vegetation growth in those areas near wetlands or where high water tables infiltrate root zones of plant species.

We will place large pieces of wood in the stream to create fish habitat. Some of the wood will come from dead cottonwood trees that are piled along the north bank of the Boise River upstream of Eckert Bridge. We are also waiting for a good wind storm in Boise to provide additional rootwads. Pool excavation and placement of rootwads will occur in the fall of 2005.


We also expect this project and additional projects along the Boise River will become a national model for habitat restoration in an urban setting. The planning and project implementation approaches can be adapted to other localities facing similar issues.

The Ted Trueblood Chapter has a solid record working with other conservation groups and with youth groups in the Boise area. We have asked for their cooperation in this project. We will incorporate this stream restoration project into our wildly popular "Trout in the Classroom" curriculum now expanded to eleven schools in southwest Idaho.