Pocatello Centennial/Rainey Levee Setback and Ecosystem Enhancement
Pocatello, ID, USA
City of Pocatello
Levee setback and ecosystem enhancement project
Services
Hydrologic Analysis
Civil Engineering
Park Planning
Landscape Design
About the project
The Centennial-Rainey Levee Setback and Ecosystem Enhancement Project is located in Pocatello, Idaho south of Interstate 86 and west of Interstate 15, and adjacent to South Arthur Avenue and Idaho Street. The project is located on two public parks, Centennial Park and Rainey Park, as well as two other parcels of land owned by the City of Pocatello. The major components of the proposed project include Portneuf River levee setbacks, ecosystem enhancements, as well as recreation and community amenities.
How we did it
In April 2019, the City of Pocatello contracted with Harmony Design & Engineering to complete 30% Portneuf River levee setback design plans, a geotechnical drilling program plan, and to prepare an Initial 408 request to submit to the United States Army Corps of Engineers (USACE) for the Centennial-Rainey project. Harmony Design & Engineering is the prime consultant and project manager, and the consultant team includes Strata, JEO Consulting, and Biota Research and Consulting. The Harmony Team refined the existing concept plan for the Centennial-Rainey project and completed a preliminary grading plan based on LiDAR data and a recent topographic survey provided by the City. The preliminary design was developed to include priorities determined by an existing Vision Study and City directions as well as flood risk reduction and federal project considerations associated with this reach of the Portneuf River.
Levee setback design will allow for side channel and wetland features, and will reconnect 1-acre of hydologically connected floodplain. The levee design will also take other project desires into consideration such as recreation, ADA access, maintenance, an amphitheater, ancillary features, and river-community connectivity, all while meeting USACE design guidelines and maintaining low flood risk.
River restoration design focuses on environmental goals including improving hydrologic functions by increasing floodplain, wetland, and riparian habitat areas, as well as improving water quality (City of Pocatello 2016). The goals of the wetland design are to serve as a demonstration of the value of floodplain wetlands and the type of habitat enhancement that is possible along the Portneuf, enhance the aesthetics of the riverside area in the park, and mitigate wetland impacts associated with the project.
The Centennial-Rainey Project is being proposed as a Section 408 alteration of the federal project. As such, the City and the project team have developed the design and project phasing in such a manner as to support the Section 408 alteration request and review process.
