Sisters, Ore. — A key part of Marc Thalacker’s original job description was drying up the stream from which his irrigation district drew water.
Entirely drying up Whychus Creek in summer ensured growers within the Three Sisters Irrigation District got as much water as possible, but by the late 1990s, it was clear the practice was bound to come under regulatory scrutiny, said Thalacker, the district’s manager.
Steelhead and bull trout were gaining federal protections as threatened species, and it appeared likely the district would face problems under the Endangered Species Act, he said.
“Why wait for the regulatory hammer when you can get out in front of it?” Thalacker said.
At the same time, the irrigation system was inefficient: Of the 35,000 acre feet of water diverted by the district, only 17,000 acre feet were delivered to farmers, he said. “The rest would seep into the ground through our leaky canals.”
Since then, the district has replaced 50 miles of its 63 miles of canals with high-density plastic pipes. When the system is fully piped in about five years, the rate of water loss will fall to 10 percent, down from more than 50 percent with canals.
Farmers are now able to get more water while diverting less from the creek.
Piping provides additional benefits: The irrigation system is pressurized by gravity, which allows farmers to stop pumping and thus save electricity. Last year, the district also installed a hydropower turbine that generates more than 3 million kilowatt hours a year, or enough to power 75 homes.
Money generated from selling electricity will help pay off loans taken out for the piping project. Meanwhile, the district plans to install four smaller turbines next year as part of a demonstration project for growers and invest in a second large turbine by 2020.
While the $2 million cost of the first turbine was heavily subsidized with grants from the U.S. Bureau of Reclamation and the Energy Trust of Oregon, a non-profit funded by state ratepayers, Thalacker expects such projects will one day pencil out financially on their own.
As Pacificorp and other major power utilities reduce their reliance on coal burning over the next decade, electricity rates are expected to rise and make such renewable energy projects economically feasible, he said.
“When we’re burning a lot less coal, this will make a lot more sense,” Thalacker said.
Three Sisters Irrigation District is one of seven districts in Oregon that have retrofit their systems to generate hydropower, and another six are examining the possibility as part of broader modernization efforts, said Jed Jorgensen, renewable energy program coordinator at the Energy Trust of Oregon non-profit.
“It is an idea that is just starting to take off,” Jorgensen said.
Hydropower turbines are often associated with piping projects, particularly when a system doesn’t have a sudden drop in elevation — in such cases, pipes are necessary to build enough pressure to power the turbine, he said. For a hydropower turbine to make sense, there has to be enough spare pressure in a system beyond what farmers need to eliminate pumps.
“You don’t want hydropower to be in conflict with how farmers get their water,” Jorgensen said.
Energy Trust of Oregon funds such hydropower retrofits that are on the verge of being financially viable but can’t quite make it on their own, he said.
Even when the revenues from hydropower alone may not make a project attractive enough, districts and ditch companies are drawn to other advantages of irrigation modernization, such as reduced electricity use from pressurization, decreased costs for upkeeping canals and fewer environmental headaches, Jorgensen said.
“That water savings is worth a lot of money and is a tremendous environmental benefit,” he said.
Aside from economic factors, the technology is more accessible because recent legislation has removed regulatory barriers to installing hydropower turbines, said Dan Keppen, executive director of the Family Farm Alliance, a group that advocates for irrigators.
In 2013, two bills — House Resolutions 267 and 678 — were passed into law, which streamlined the federal government’s approval of small hydropower facilities, Keppen said.
Previously, hydropower retrofits were lumped in with larger projects even though they modified existing irrigation systems and had no environmental impact, he said.
The time and expense of obtaining permitting was often greater than building the project itself, but now many of these impediments have been removed, Keppen said.
Irrigation systems across the West are often reliant on gravity, with water being pulled from behind a dam or distributed by flowing from higher to lower elevations, so they’re already designed to accommodate hydropower, he said.
“You’re going to have Mother Nature on your side,” Keppen said.