Irrigation district installs new gates on Moses Lake

MOSES LAKE — The Moses Lake Irrigation District installed six new gates to hold water in the lake Wednesday.

The gates replace others installed near the sand dunes in 1928, keeping irrigation water in Moses Lake.

District workers discovered the gates no longer functioned three months ago. Curt Carpenter, the district’s general manager, explained the original gates were corroded, causing parts of the gates to break.

“We removed it to repair that stem and we found the old gates were made out of cast iron and the stem threads into them split,” he said. “Then the rails that they run on were so corroded that you could see through it.”

When district employees investigated the other gates, they found similar problems, Carpenter said.

“We basically had three months to design, build and install the gates. It’s been quite a project,” he said.

A Wenatchee-based structural engineering firm designed the gates, and Inland Mechanical in Moses Lake built the new gates in time for them to be installed. The materials for the gates cost about $50,000, Carpenter said. The district installed the new gates.

“If you were to go to Waterman, who builds gates, … each gate is over $20,000, if you went off the shelf,” he said. “You’re looking at $20,000 a piece. You’re looking at about ($250,000,) just for the gates.”

Carpenter said the challenges in completing the projects included finding an engineer familiar with the type of structure needed and dealing with a 1928 earth dam.

“Then in the installation, the old ductile iron rim that’s around the entry into the pipe. That’s where all the attachments were,” he said. “We also designed in some modifications.”

The modifications included moving the mechanism which lowers the gate, Carpenter said. District employees needed to stand on a truck, parked on Sand Dunes Road to open and close the gates.

“We were having to stand out in traffic with a great big wrench,” he said. “So we just took advantage of a more ergonomic design.”

The crew installing the gates needed to be careful since the Columbia Basin Project’s irrigation canals started filling up, Carpenter said.

“It’s not such an issue of having them operable yet, because we won’t totally close until June, but working is pretty dangerous with the currents,” he said. “That’s what the critical stage is at this point.”