Norwich — Praising the spirit of regional cooperation that will bring an emergency water supply to Sprague and enhanced grants for $15.2 million in water system upgrades for Norwich Public Utilities, officials from both towns broke ground Tuesday on a $3.2 million water line running from Occum to Baltic.

The project — criticized at times in Norwich, because NPU is paying for the line extension outside the city — will provide a reliable emergency supply to Sprague through a new 9,700-foot water line running along Route 97 from St. Joseph’s Church in Occum to the Babe Blanchette Softball Field in Baltic. At times, Sprague’s backup well system provides only 10 days of water supply, officials said.

About two dozen officials from Norwich, Sprague and the state Department of Public Health gathered at the St. Joseph’s Church parking lot Tuesday morning to mark the start of construction.

“This project is a great demonstration of cooperation between towns and communities for the future,” NPU acting General Manager Chris LaRose said.

Construction will begin next week and is expected to be completed by November. No road closures are expected, NPU spokesman Chris Riley said, and there will be flaggers to direct traffic at construction spots. Any construction ditches will be covered over at the end of each work day, and no night construction is anticipated, Riley said.

Sprague needed the water, LaRose said, and NPU needed state support for its water system upgrades. By pairing those $15.2 million upgrades with the regional cooperation project, NPU became eligible for 30 percent of project costs in grants through the state Department of Public Health. Without the partnership, NPU would have received only 8 percent in grants for the projects.

The $3.2 million Sprague water line will be funded with a 50 percent grant, 50 percent low-interest loan through the state Department of Health’s Clean Water State Revolving Fund and will provide Sprague with up to 60,000 gallons of water in an emergency.

Sprague First Selectwoman and state Sen. Cathy Osten, D-Sprague, recalled when she first was elected, a town official told her: “Oh, by the way, we only have 10 days of water supply.” Osten said town officials have been looking for a long-term solution for years, but the small town could not afford to install its own water line.

She said her Senate district represents 10 towns, and at the southern end, Groton and Ledyard are working on a similar regional water project.

“This should be happening more,” Osten said. “All of us benefit from this project.”

The NPU water system upgrades include a $7 million upgrade to the Stony Brook Water Treatment Plant, $2 million to upgrade the Deep River Water Treatment Plant, $5.4 million to upgrade the transmission line from the Stony Brook plant and $850,000 for a new water mixer and aeration system at the Occum water tank.

c.bessette@theday.com