|Bids to be let for augmentation pipeline|
|Written by Wauneta Breeze|
|Thursday, 26 January 2012 20:07|
Bid opening expected in early March
By Russ Pankonin
The Imperial Republican
Members of the Upper Republican Natural Resources District voted to let bids for a 20,000-foot pipeline to augment water flows in the Republican River.
Engineer Chris Miller of Miller & Associates of Kearney reviewed design and impact studies with the board at their Jan. 12 regular meeting.
Last year, the URNRD purchased a 4,000-acre, $10 million tract in southwest Dundy County north of Parks. Irrigation will be retired on the 3,261 certified acres that includes 23 wells.
Then, when needed, water will be pumped from wells on the tract to help the district meet compact compliance issues.
Miller said they completed a number of model runs to measure the drawdown in the local aquifer and impact on neighboring wells.
Miller said they were able to best identify areas for locating the augmentation wells to minimize impact on neighboring wells. Much of the impact will occur within the 4,000-acre tract.
By locating the wells to the north end of the tract, the pumping will result in less streamflow depletion than wells closer to the river.
Miller said they ran scenarios at three different pumping levels to provide 5,000 acre feet of water for compliance, 10,000 acre feet and 15,000 acre feet
As presently planned for bidding, 20,000 feet of 24-inch pipe will carry the water from the well field to its discharge point into Rock Creek.
They also modeled the impact downstream from adding that much water to the creek bed.
Since the water would be pumped in over a period of time, the creek would see a peak rise of about one foot. The discharge should not cause any flooding on the creek.
The water will be discharged above the Rock Creek fish hatchery, operated by the Nebraska Game & Parks.
Miller noted the water will run through the hatchery, into Rock Creek Lake, and then back into the stream below where it meets the Republican River near Parks.
Level of pumping
Miller suggested the board look at pumping from five wells initially.
Of the existing wells on the tract, most were drilled in the mid-1970s. He questioned just how good those old wells would be for such a project.
One well was re-drilled in 2009 and he suggested keeping that one and drilling four new wells in place of the others.
New wells will be more efficient, he noted, and will provide a better long-term solution.
He said it appears the new wells could each generate 1,240 gallons per minute, with only about 30-40 feet of drawdown, which would not affect neighboring wells.
He said that could easily generate the 5,000 or 10,000 acre feet for augmentation over the course of a year.
He said an additional well or two could be needed to hit the 15,000 acre-foot mark. This would likely result in running the pumps full time.
He suggested using submersible wells versus turbine pump wells. He said that while the submersibles may not have as long of life as a turbine, the regular maintenance needed is far less, creating a trade-off.
A submersible pump would also allow for better winter operation, Miller noted.
Bids will be opened in early March, possibly late February.
Miller said the bids will state that time is of the essence and will be a factor in bid consideration.
Specs will also be sent out for bids on drilling test wells for the four new wells being proposed.
|Last Updated on Thursday, 26 January 2012 20:08|