Crews worked to build and install a 2,000-foot-long flood barrier to protect Zoo Boise from potential flood water.

They call it a "muscle wall" and it's similar to the one that was built in May to protect a gravel pit near Eagle Island.

Ada County is leasing these barriers from a company called Flood Resolution.

Crews were out early this morning stacking the barriers in between the sidewalk and Boise River right next to Zoo Boise.

The fear is that the Boise River could eventually rise above its banks and flood into the zoo.

The flood barrier is expected to cost $130,000. Most of the cost is covered by grant funds from Ada County Emergency Management.

Zoo Boise says building the barrier is a necessary step to protect the zoo's more than 200 animals.

“It really is a precautionary measure on our part,” said Boise Parks and Recreation Director Doug Holloway. “Moving 200 plus zoo animals is a very difficult task. We felt it would be a more prudent reasonable task to put in the muscle wall and hope that it’s actually for nothing.”

As a precaution, Zoo Boise managers are also making preparations to relocate the animals if the zoo flooded.

The plan would be to move all the animals to the snow removal equipment barns at the Boise Airport. That move would likely take 5 to 7 days.

Zoo officials say the move would pose difficult logistics but that they have to prepare for it just in case.

"Given what's going on with the river right now and what we've received from the Corps, we may only get between 18- and 24-hours notice that river may rise, so it wouldn't give us the time to fully implement that plan,” said Zoo Boise Director Steve Burns.

You might be wondering how the zoo plans to move Jabari the giraffe. Zoo officials say moving him might not be an option.

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"In the giraffe’s case, it may be that we have to sand bag the barn and leave him here with people to take care of him if we aren't able get him moved," said Burns.

Zoo Boise says they have also postponed the arrival of their new giraffe to later this summer.

They want to wait until the flood threat is gone before bringing in another animal that would be difficult to move.