SACRAMENTO-

It’ll never fit under any fir tree, but the more than 200,000 pounds of iron and steel that hit the highway in Dunnigan Thursday morning means Christmas in March for the U.S. Army Corps of Engineers.

“Pretty excited that they’re coming and they’re arriving on site. That’s a huge milestone for us,” Katie Huff, senior project manager with the U.S. Army Corps of Engineers, said Thursday.

This March milestone for the Folsom Dam is  the first of six massive bulkhead gates that will protect the Sacramento Valley from a devastating flood starting in 2017.

“Once you have water flowing through the control structure itself, the bulkhead will be in the fully raised position and the tainter gate will slowly raise up to release the amount of water,” Huff said as she explained how the huge pieces will eventually work together.

Up to 800,000 cubic feet of water per second, if need be,  can flow out of what’s being built right now and the existing Folsom Dam so flood waters don’t over-top it.

And while gates are supposed to be about allowing access at least 50 percent of the time, the California arrival of this component has been all about closing off access as its traveled to Folsom.

“To visualize that it’s about two lanes of traffic a bulkhead gate will take up each time it comes down from Oregon where it’s being fabricated,” Huff said.

That meant a CHP escort and rolling lane closures along parts of Interstates 5 and 80 as a gate the weight of 15 school buses passed by.

A temporary inconvenience for a lifetime of protection.

“Since these gates are 50 foot lower than the main dam they will be able to release water quicker and faster than we could have done with just the main dam in place,” said Huff.

Five more bulkhead gates and six tainter gates for this $900 million project will be driven to the Folsom Dam construction site between now and August.

The first gate ended its 600 mile journey on Folsom Lake Crossing at 11 p.m. Thursday, awaiting a fall installation.