A project to replace a section of canal in southwest Bend with a 3,000-foot irrigation pipeline may be delayed for a year as a federal agency completes an environmental study.
The Central Oregon Irrigation District was prepared to start piping a section of canal west of the Brookswood Boulevard bridge in December, but it learned just before ordering pipe that the federal Bureau of Reclamation still needed to complete an environmental study, district manager Craig Horrell said.
“If they can complete some of their tasks by Jan. 1, we could probably get in there and construct it this spring,” Horrell said.
The bulk of the construction would take place behind 25 houses on Rock Bluff Lane, which now have backyards abutting the canal.
In addition, the irrigation district hopes to sell at least some of the 156.4 acres it owns in that area for future development, though there’s no timeline yet for that sale. The district hopes to use proceeds from selling some of its land for future water conservation projects, Horrell said.
The land, which sits between the Deschutes River and existing housing developments, is all zoned for standard or low-density residential housing, meaning only single-family homes or duplexes could be built. If a proposed city development code change allowing triplexes and fourplexes in standard residential zones passes, fourplexes could be built.
Whenever a project is done by a federal agency or using federal money, the National Environmental Policy Act of 1970 requires that federal agencies — in this case, the Bureau of Reclamation, an agency in the Department of the Interior that oversees water management in 17 Western states — evaluate environmental, social and economic impacts of the project and allow input from the public.
Because a portion of the $5 million piping project came from a federal grant, the bureau needs to complete a study, said Edna Rey-Vizgirdas, a Boise, Idaho-based bureau spokeswoman. How long that takes depends on what type of study is needed, and the bureau will decide that based on some initial scoping.
“It could take a few months to over a year,” Rey-Vizgirdas said. “The purpose is to implement better projects.”
Piping the canal will take several months of work, and the irrigation district can’t be working on it during irrigation season, which runs from April to November.
The Central Oregon Irrigation District has already piped several portions of its canals in Bend, including a section of the Pilot Butte Canal in Juniper Ridge in 2010. Piping reduces the amount of water the irrigation district needs to draw from the Deschutes River, Horrell said.
“Our system’s 100 years old and it’s in desperate need of repair,” Horrell said.
Because of Central Oregon’s volcanic geology, the bottoms of canals in the area consist of sand and porous lava rocks. It’s easy for water diverted from the river to end up seeping through the rocks instead of making it to farms that rely on the canals to irrigate, so the irrigation district ends up diverting more water to make up for that loss.
To lose less water, the irrigation district could choose to line the canal, which would cost less upfront and keep the aesthetics of a waterway. But linings require expensive maintenance and they can make canals too slippery for people or animals to climb out of if they fall in.
Piping, meanwhile, can cost more upfront but be less expensive in the long term. It also provides options for pressurized hydropower.
When the 3,000-foot section of canal west of Brookswood Boulevard is piped, the irrigation district predicts it would restore 5 cubic feet per second of water to the Deschutes River. That’s the equivalent of leaving 32,025 full bathtubs in the river each day.
Once the canal section is piped, the irrigation district intends to cover the pipe and plant native vegetation on top of it. It would maintain a paved access road on the north side and a meandering dirt trail on the southern side.
“It was an opportunity to take something that people perceive as theirs, which is trails along the canals, and enhance it,” Horrell said.
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