Crews building "muscle wall" flood barrier around Zoo Boise

Posted at 2:45 PM, Jun 06, 2017
and last updated 2017-06-07 07:55:13-04

On Wednesday, the City of Boise will began taking precautionary measures to protect Zoo Boise in the event that hot weather this week and fast-filling reservoirs force federal water managers to release more water into the Boise River, according to a news release.

City engineers and other agency partners with the Ada County-wide team working to manage flood response Tuesday began preparations to install a 2,000-foot-long, four- to two-foot-tall “muscle wall” flood barrier. “The structure is similar to the wall constructed to protect a gravel pit near Eagle Island last month,” said City spokesman Mike Journee.

“Zoo Boise managers and emergency responders are taking the proactive step because of the difficult logistics, expense and potential stress to animals if relocating the Zoo’s more than 200 animals became necessary. Additionally, federal water managers are now saying that this week’s significantly warmer weather and quickly shrinking capacity in upstream reservoirs means that notice of river flow increases could come just 24 hours in advance. That would give zoo managers little time to plan an animal evacuation, if needed,” he added.

“We are doing this out of an abundance of caution to ensure we are not faced with planning a full-scale evacuation of zoo animals on short notice,” said Doug Holloway, Director of Parks and Recreation for the City of Boise. “The investment to protect the animals and zoo property is a good one, given the circumstances.”

The construction of the flood barrier will force the closure of Julia Davis Drive between the bandshell and tennis courts. Friendship Bridge, the pedestrian bridge between Boise State University and Julia Davis Park, will remain open to through-traffic for pedestrians and bike traffic. However, the Greenbelt through the park and the entire city remains closed due to the high water and safety concerns.

“The conditions on the Boise River and the Greenbelt become more dangerous as time goes by and the water undermines the tree roots and the foundation of the Greenbelt,” said Boise Fire Chief Dennis Doan. “These conditions are potentially fatal to the public and first responders. We ask all residents to respect this closure to prevent any tragedies.”

Evacuating the more than 200 animals at Zoo Boise would cost approximately $500,000 to $600,000, plus post-flood clean-up costs and revenue lost with the zoo’s closure, officials said.

“Additionally, such a move would could be extremely stressful to many of the animals. The flood barrier is expected to cost approximately $130,000 and cause animals little or no concern. Of that cost, $118,500 will be covered by grant funds from Ada County Emergency Management. Installation is expected to take one or two days and the barrier will remain in place until the zoo is no longer threatened by high water,” Journee stated.

Currently, the Boise River is flowing at approximately 9,300 cubic feet per second. While federal water managers have no immediate plans of increasing those flows, they have warned city and county officials that current weather conditions likely mean advanced warning of just 24 hours if and when increases are necessary -- much shorter than the three- to four-day window of previous weeks.