Residents who want to preserve old wooden flumes that carry Nevada Irrigation District water turned out in force Wednesday night, while downstream ranchers argued their irrigation water was being restricted by the outdated water system.

At a special evening meeting, NID directors postponed a decision to replace the flumes after receiving 50 pages of documents late in the day from lawyer Stephen Volker and two technical experts.

The flumes are located between the DS Canal's intersections with Banner Mountain Trail Road to the east and Banner Lava Cap Road to the west. NID wants to replace the flumes, built in 1928, with 72-inch-diameter steel pipe. Officials say it would improve reliability and increase capacity of raw water deliveries to agricultural users in Grass Valley, Penn Valley and - for occasional supplemental deliveries - Chicago Park.

Replacing the structures would diminish the aesthetic appeal of the area, and the construction project would degrade the environment, residents said.

"The visual impact would be permanent, monumental and irreversible," said Dennis Manyak, who lives on more than 2 acres on Big Blue Road.

Flume No. 17 passes along the edge of his back yard, offering a charming vista from his home up the hill. He and his wife walk the DS Canal and said the project could lower his property values while ruining the beauty of the trail that many Nevada City residents walk.

"Why the massiveness? These old flumes have worked fine for a century," Manyak said.

Meanwhile, the demand for more water is growing daily.

"Probably over 500 people we've told, 'sorry we can't give you any water until we lift the restrictions,'" said NID water superintendent Larry Markey at the public meeting. He said the flumes are unsafe for crews to maintain.

A Chicago Park rancher dressed in a striped shirt and Wrangler jeans who owns 60 acres in Chicago Park said he cannot irrigate his land because of a freeze on water deliveries caused by the DS Canal.

"It seems like some people take ownership of that ditch over time. It's for the benefit of all residents of Nevada County," he said.

Concerns raised during Wednesday night's special hearing could influence mitigations to the project before it goes before the board early next year, said Assistant Manager Tim Crough.

That may not satisfy some residents who have threatened litigation if NID ignores requests for an extensive environmental report.