From The Grand Junction Daily Sentinel (Dennis Webb):
The city of Grand Junction is planning to fix and refill its Purdy Mesa Reservoir on the south side of Grand Mesa this year after successfully obtaining a $1 million loan and $100,000 grant last week from the Colorado Water Conservation Board.
The city plans to spend about $1.15 million altogether on rehabilitation of the dam, which has about an 80-foot-long crack in it and has had to be emptied pending repairs.
The reservoir, also known as Hallenbeck Reservoir No. 1, holds about 700 acre-feet. An acre-foot is about 326,000 gallons.
The reservoir plays a particularly important storage role in case of drought, and also lets the city regulate water in the adjacent, larger Juniata Reservoir and improve its water quality.
“It’s definitely something that we want to have in our raw water storage in event of a drought condition,” Bret Guillory, utility engineer for the city, said of the out-of-service reservoir. “It plays a fairly critical function in our raw water storage system and it will be good to have it back online.”
The reservoir also is stocked by Colorado Parks and Wildlife for fishing. Guillory said the state-record bluegill came out of the reservoir.
The crack developed in 2014 in the downstream slope of the earthen dam. Guillory said design work for the repairs is complete and the city will solicit for contractors to do the work. Repairs probably will start later in June and take six to eight weeks, after which the reservoir can start to be refilled.
The rehabilitation work will upgrade the dam to current standards and improve its structural integrity, Guillory said. Earthen dams by their nature have water seep through them, but he said what’s called a blanket filter that makes use of sand will be installed to collect seepage into piping rather than having water move through the dam in an uncontrolled manner. Earthen material will be placed over the filter to hold it in place and further stabilize the dam.
The loan for the project comes with a 2.65 percent interest rate and $10,000 service fee, and will be paid back over 20 years.
The project is one of a number of water system upgrades the city is undertaking this year and in coming years.
It has begun raising water rates to pay for them, and plans to raise rates more than 50 percent altogether over seven years. The main upgrade involves replacement of cast-iron lines with PVC lines less prone to leaking or breaking.
Guillory said that if the city hadn’t gotten the loan, it might have had to delay its water-line replacement work for a year.