Photo courtesy of the Quincy-Columbia Basin Irrigation District.

WASHINGTON STATE EDITION

A Case Study in Extending Canal Life at the Quincy-Columbia Basin Irrigation District

District Background

QCBID is one of three irrigation districts operating the Columbia Basin Project, which brings water resources to the Columbia basin. In 1902, Congress passed the Reclamation Act, which authorized the construction of irrigation storage and delivery systems, including projects for the Columbia basin region. President Franklin Roosevelt set the Columbia Basin Project in motion with the construction of the Grand Coulee Dam, which began in 1933. A railroad was built to move materials and workers to the building site. Congress then authorized the Columbia Basin Irrigation Project in 1943, and the first water deliveries started in 1948.

Today, because of canal expansions and additional pumping plants, the number of irrigated acres is over 680,000 in the Columbia basin. In addition, the Columbia Basin Project provides power for millions of homes, controls flooding in the lower Columbia region, creates habitat for endangered species, and provides the public with areas of recreation.

In 2009, QCBID entered into a coordinated water conservation plan with the East and South Columbia Basin Irrigation Districts and the Washington State Department of Ecology to conserve water and alleviate canal capacity. QCBID has since undertaken a canal-lining program to save water and reduce seepage. As part of that program, this past winter QCBID undertook a 2-mile lining project.

 

The Challenge

Repairing QCBID canals is a tricky operation, because work must be completed in a short time frame: from when the water is shut off in mid-October to when the water needs to be turned back on in early spring. In addition, winter snow and rain make it difficult to schedule access to the site and the installation of concrete.

 

The Liner

Intertape Polymer Group (IPG) manufactured the geomembrane composite liner, the Armorpad 3NWLD, which was fitted to the exact dimensions of the canal. The Armorpad 3NWLD is a thermally bonded, multilayer system of material composed of a scrim bonded with impermeable coatings, which in turn are bonded with nonwoven material on the outside. In the case of this project for QCBID, the nonwoven component also acts as a bonding surface for the concrete, which was applied directly onto the composite.

 

The Repair

In November 2016, QCBID began the canal repair with the reshaping of the canal. IPG delivered the liner to the site in 40-foot-wide, 300-foot-long rolls. The rolls were cut with enough slack to be buried in the anchor trench. Halme Construction of Spokane, Washington, installed the geomembrane.

First, Halme placed one side into an anchor trench on the edge of the canal and rolled the entire 300 feet of ArmorPad 3NWLD out, backfilling with a small amount of soil to hold the liner in place and protect it from wind. Next, the workers pulled the other side across the bottom of the canal and placed it in an adjacent anchor trench. On some of the corners that approached 90 degrees, Halme left enough slack material to make a cut and fold it over.

Halme overlapped the panels of liner by 1 foot, and each overlap was shingled downstream—a common oversight when placing liners in canals. The next step involved connecting each seam of the large panels together with an adhesive that provides an extreme bond to the composite liner. For this task, IPG loaned Halme a hot melt adhesive unit that heats the adhesive, pumps it through a nozzle, and delivers three beads. Halme workers made two or three passes on each seam.

For the final step, Halme applied 4 inches of concrete directly over the top of the ArmorPad 3NWLD without damaging the liner. Halme built a concrete buggy, which allowed it to install the concrete quicker than doing it manually. The concrete mixers pulled up to the buggy and dumped their concrete. As the concrete was fed down into the canal, the buggy moved along with a single-track hoe.

QCBID finished canal repair in March 2017, prior to the start of irrigation season.

 

The Results

The entire operation was completed ahead of schedule and is now helping to save water throughout the Columbia basin. So far, the QCBID has lined more than 6 miles of rehabilitated canals with an estimated water savings of more than 3,860 acre-feet.

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