A recently completed infrastructure project enables Boise City Canal Co. to use more of the water to which it is entitled — particularly in drought years — and better contribute to the overall efficiency of the Boise River system.

The company’s 159-year-old water right is senior enough to ensure an ample supply as long as the infrastructure can access and move the applicable volume.

But amid drought in late summer 2021, BCCC got just less than half what it was entitled, essentially because its system did not function deeply enough as river levels dropped. The company ended its irrigation season more than a month earlier than usual.

“The level of the Boise River at the BCCC headgate is largely determined by the amount of water requested by large downstream users such as the Pioneer or Riverside irrigation districts,” Boise City Canal Co. water manager Mike Harrison said in an Idaho Water Resource Board news release. “When those users shut down, the elevation of the river drops,” leaving the headgate unable to deliver enough water to serve the company’s users.

“The problem was particularly acute in late summer 2021, when the downstream users were curtailed early,” reducing flows from the reservoir system into the river, he said. “With climate change expected to cause more similar summers, we wanted to make sure we could access our full allotment.”

Improvements to BCCC infrastructure, which is on the upstream side of the Boise River system, also can help the company use water more efficiently, get it where it needs to go and waste less, Harrison said in an interview. The improved efficiency also has potential to benefit post-irrigation return flows downstream.

The company installed a new headgate structure— on the river’s north bank just upstream of Warm Springs Golf Course — and deepened the canal.

Work included lowering the floor of the intake structure and pouring a new concrete floor, replacing two automated metal headgates, replacing the return weir and installing two automated metal gates, lowering the culvert used to access the headgate, excavating 300 feet of canal to match the new headgate elevation, and installing communication equipment to report real-time water usage to Water District 63, according to IWRB.

“In addition to allowing Boise City Canal to access its water right during times of drought, these modifications will improve flow reliability during the entire irrigation season,” Harrison said in the release. The project essentially will “more than double our canal’s capacity during times of low river flow.”

Funding for the $366,000 project included a $122,000 aging infrastructure grant and $200,000 low-interest loan, both from IWRB.

The company serves about 700 small-acreage urban shareholders and many city landmarks including the golf course and Julia Davis Park. The canal runs through several Boise neighborhoods, irrigates about 300 acres in city parks and is a major contributor to drinking water company Veolia’s purification plant adjacent to the golf course.

Customers include small-acreage residential, farm and pasture owners, Harrison and Alan Winkle, former BCCC president and longtime board member, told Capital Press. Water uses include fruit tree and arboretum tree production, for example.

With a reliable late-summer flow, the company is considering extending service to the Idaho Botanical Garden, an additional golf course and two more sizable parks, according to IWRB.