This article was published on: 10/11/11 12:00 AM

Ditch piping and water feature move forward

9/20/2011 1:42:00 PM

The city and the Three Sisters Irrigation District (TSID) expect to finalize an agreement Thursday night that will include putting the water from the historic “Uncle John” ditch in a pressurized pipe, installing 600 feet of mainline pipe for the city, and preserve a cherished ‘water feature’ at the “Little Bridge” on the Peterson Ridge Trail (PRT).

The work will be done at less than $1,000 total cost to the city.

By piping the Uncle John, TSID expects to recover an estimated 22 percent in water flow by conserving losses due to evaporation and ground seepage associated with open ditch irrigation. The water will be returned to Whychus Creek, resulting in an estimated increased water flow of just under three cubic feet per second (CFS).

All but the $1,000 for the turnout hardware for the water feature will be covered by a variety of grants obtained by TSID. The current water flow at Little Bridge is between five and 10 CFS. The city’s design for the new water feature will consist of pools flowing over rocks, resulting in far less water consumption and significantly reduced water flow while maintaining the aesthetic features of the water feature.

At Councilor Pat Thompson’s insistence, an oversized four-inch valve will be installed on the TSID pipe. This will allow the feature to be filled quickly, and the flow then turned down.

The cost of the water usage analysis for adding the water feature will be covered by the Forest Service and the Deschutes River Conservancy.

TSID obtained an “industrial water permit” for the water to be consumed by the water feature. This permit, combined with the fact that the Uncle John ditch is covered by a homestead right-of-way that predates the creation of the Forest Service, guarantees that the water cannot be diverted for other use at a later date.

“You are entitled to the water. It is a beneficial use. Stock water is at the top of the priority list. The water will not be diverted to other uses,” said TSID Director Marc Thalacker.