More with less: How irrigation modernization makes life better for fish, farms and families
Teamwork: Three excavators (one unseen from the left, pulling a yellow/brown line) work together to carefully place thermo-plastic pipe, 2 feet in diameter, into a curvy ditch. The complicated maneuver pays off big time, as part of an irrigation modernization project to conserve much needed water from evaporation and leaks. Photo courtesy: Swalley Irrigation District
Modern irrigation projects help reduce water loss to vegetation, which can soak up a lot of water through their roots. The Rogers Latteral Canal, seen in both pictures above, provides an example. Photo courtesy: Swalley Irrigation District
Many of Oregon’s highly productive croplands are irrigated, and in areas like the rolling wheat lands of northeastern Oregon, farmers rely on rainfall to water their crops. We are used to seeing huge sprinkler systems mounted on wheels moving slowly across a field as they deliver water to thirsty plants. (In some places, we don’t see sprinklers because the farmer is using drip irrigation, but the crops are being watered nonetheless.)
When we hear about irrigated agriculture using 80% of Oregon’s water, it’s those sprinklers we commonly think of. Less often do we consider how the water gets from the river to the sprinklers.
Well, think ditches. Much of that irrigation water is delivered to farms in open ditches and canals. Snaking for miles across the landscape, these ditches and canals were some of the first things built when settlers moved into Oregon from the east. There are canals in central Oregon dating back to the 1900s and earlier. Early irrigators used dynamite to blast through the basalt bedrock, hauling rock and dirt with shovels, horses and human hands, and many of those canals are still in use today. Pooling resources, groups of irrigators formed irrigation districts to manage and deliver the water to landowners within the district boundaries.
Across the Deschutes basin and in other parts of Oregon, irrigators are rethinking their water delivery systems. Old ditches and canals, while wonders of technology for the times, are extremely inefficient. As much as 50% of the water carried in those open canals is lost to evaporation and to leakage. Some canals have been lined with concrete or other materials to reduce leakage loss, but evaporation is still a problem.
Thermo-plastic pipes (bottom) get welded together to form the length of an excavated portion of land for irrigation. A system of valves (top) are installed throughout the project to carefully track how much water is flowing and to whom. Photo courtesy: Swalley Irrigation District
A new generation of irrigators are going high-tech, using modern materials to install systems of buried pipes, valves and meters to deliver water to farmers. These new systems run in the same place as the old canals, delivering pressurized water to landowners and reducing water loss dramatically. Since a piped system reduces the amount of water needed to deliver irrigation water to landowners, some of that water can be returned to the river, increasing stream flows and protecting fish, wildlife, water quality and watershed health and functionality.
Swalley Irrigation District, established in 1899, is one of the smaller water delivery districts in central Oregon but also one of the oldest. Located west of Highway 97 just north of Bend, the district delivers water to 668 landowners spread over 4,331 acres. In April, the District completed its latest modernization project. Replacing approximately 16,000 linear feet of an open and highly inefficient canal with 24” pressurized pipe lets the District return over 1.2 million gallons of water per day to the river. According to Jer Camarata, manager of the Swalley Irrigation District, there are many benefits to ~53 water users the district serves: “water supply reliability and delivery efficiencies conveyed to water users have been greatly enhanced, on-farm energy usage from pumping has and will continue to be reduced over time, and public safety issues associated with the canal have been ameliorated.” And the benefits to the river are also significant. Camarata estimates that with the completion of this project, Swalley has piped almost 70% of its delivery system, with a total water savings of more than 29 million gallons per day during the irrigation season-all of which goes back into the Deschutes River.
Building a piped water delivery system is a challenge. The work must be done between November and March, between irrigation seasons. The materials are expensive-the Rogers Lateral project cost nearly $1.93 million-and those funds must be in-hand for the project to get underway. Some money came from the federal government, channeled through the Natural Resources Conservation Service, and matched with funds from the Oregon Watershed Enhancement Board and the District itself. Tons of rock were broken up and moved, miles of High Density Polyethylene (HDPE) pipe welded and moved into position, valves and water meters installed and tested.
The HDPE pipe has a minimum lifespan of 200+ years and is earthquake resilient; delivery valves and water meters are state-of-the art technology, allowing for highly accurate water delivery control and monitoring.Moving the lengths of welded pipe was a ballet of backhoes choreographed by engineers. Once
the pipe was in the ground, the canal backfilled, and 31 access gates installed, the project was ready to deliver water for the 2020 irrigation season. Native plant seeding projects are planned for the fall.
Swalley and the other Deschutes irrigation districts have similar projects in the pipeline, on hold as they seek funding. The return to the basin for these investments is huge-farmers and landowners have reliable water and can reduce energy costs; fish, wildlife and recreationists have clean, protected and reliable streamflows, and rural homes and families throughout the basin are more secure in their livelihoods.
A cart drives over land that contains the irrigation pipe buried four feet below the ground near a water storage pond (right) where birds like to hang out. Photo courtesy: Swalley Irrigation District
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