The Alta Harris Creek Side Channel Project
The Alta Harris Creek side channel project will restore habitat for the purposes of restoring spawning, rearing, and over-wintering fish habitat, all of which have been lost over time due to a changed river ecosystem. The channel will be more than one mile in length. Alta Creek Aerial It will be constructed adjacent to the Harris Ranch development along the Boise River and will be part of a planned riverfront natural conservation area. Public walking paths will be coordinated with side channel project. Eventually the goal is to link the side channel to the Barber Pool to provide a steady flow in the channel and to reconnect the Boise River to Barber Pool.
Construction of Alta Harris Creek began in spring 2005. Segments of the stream channel have been constructed over time, and through the end of 2007 more than 450 community volunteers have donated 1450 hours of service in planting and monitoring the stream in its development.
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. On June 23, 2005 US Bureau of Reclamation Commissioner John Keys visited the Alta Creek project.
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.
These studies point to the habitat limitations and how a new side channel could benefit the Boise River by providing quality trout spawning, rearing, and pools for winter holding habitats. 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. This 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.
Lessons learned from this project have already been transferred to additional (smaller-scale) side channel and riparian/wetland habitat projects at downstream areas where habitat restoration and connectivity can occur along the Boise River.
