Carson City could again call for voluntary water use reductions this summer because of a delay upgrading the Marlette-Hobart Water Supply System.
Closure of the water system for upgrades will reduce the city's summer water supply by about 10 percent.
Upgrades expected to be finished last year won't be done until August or September. The state said the project has had several unexpected delays since it started in July 2007.
Pat McInnis, chief engineer of the state buildings and grounds division, said the project at the Marlette Lake and Hobart Reservoir in the hills west of Carson City has been challenging from the beginning.
He said the state needed six years to get federal permits, encountered a protected beaver species and had work limited to summer months because of snow.
A single-lane road to the system also only allows one crew at a time to work on the project, he said.
City and state officials have have been working together, said buildings and grounds administrator Cindy Edwards, and the project will be done this year.
"It's just more construction than anticipated," she said.
The upgrade will allow workers to control the system remotely.
Water supplies will be able to be turned on in spring rather than summer to meet major summer demands. The state used to have to send workers up the mountain to pump additional water when needed.
The city blamed two voluntary water restrictions last summer on the construction, hot temperatures and declining creek flows.
Carson will pay $7.7 million of the $9.3 million upgrade through city water fees. The U.S. Environmental Protection Agency and the Carson Water Subconservancy District will pay the rest.
Edwards said the cost is close to the original estimate for the work on the more than century-old system providing water to Carson City and Virginia City.
Ken Arnold, city public works operations manager, said the city has more than enough water supply, but the system of pipes and tanks can't deliver water quickly enough during peak demands in the summer. The city uses more than five times as much water on a summer day than on a winter day.
Lack of water from the system could again force the city to juggle its resources and ask residents to reduce their water use, Arnold said.
People cooperated with the voluntary cutbacks last summer, he has said.
Carson City's water supply comes from surface water and groundwater. Surface water flows from Marlette Lake water system and creeks and streams, such as Kings Canyon Creek. Groundwater is pumped from wells around the city.
In winter, the city depends completely on surface water and in summer it uses about 40 percent surface water and about 60 percent groundwater.
- Contact reporter Dave Frank at firstname.lastname@example.org or 881-1212.