Timeline and Restoration
Plantation Island Bridge Project
2017 Major flooding of the Boise River
APR 2017 Bridge was removed for safety
JUN 2018 FEMA grant award
JUL 2018 Fundraising begins for $75,000
needed to restore the bridge
OCT 2018 Goal to reach $75,000
NOV 2018 Construction bids to repair
the land and restore the bridge
DEC 2018 – JAN 2019 Construction
JAN 2019 Re-open the section of green belt
Flooding on the Boise River caused erosion of the embankments and pathway of the Greenbelt Bridge near the Planation Islands near Boise and Garden City. April 3, 2017 a hired crane removed the bridge from the embankments when concern rose that the bridge structure could fail and the bridge could fall or be swept downstream.
The embankments are now fully visible, erosion and undercutting are observable. An Engineering firm has identified possible solutions for the grouting and repair of the banks of the island next to the embankments. The bridge was anchored to the west side abutment and part of the steel anchor plate on the west end of the bridge to which the bridge was bolted was cut away. The embankments and the bridge were reviewed by an engineering firm and are considered to be in good shape.
The goal of this project is to return the bridge onto the embankments and restoration of the north bank of the island to return the Greenbelt to full functionality.
All work must follow all Federal, State and County regulations with regards to construction, river work, and safety, to include permitting and environmental protections.
The tasks for the restoration project are:
Concrete grout any voids or undercutting around or near concrete bridge abutments.
Using containment fabric where possible, place suitable fill material and compact the fill near and around the east and west side abutments and north side of the island for approximately 100 feet from east side abutment.
Install rip-rap to protect the abutments from river flows equaling the 2017 Boise River flood.
Install rip-rap to protect the north side of the island near the bridge from river flows equaling the 2017 Boise River flood.
Install asphalt paving to repair the west side bridge approach up to the reinstalled bridge.
Install asphalt paving to repair the east side bridge approach for approximately 90 feet up to the reinstalled bridge.
Repair or replace the east side anchor plates of the bridge abutment.
Using a crane sufficient to move the bridge, lift and swing the bridge, returning it to its original location.
Install the anchor bolts on the west end of the bridge.
The overall project is expected to cost between $160,000 and $200,000.