Thousands of Carson Valley residents will find themselves living in a floodplain if new federal maps are implemented.
The Federal Emergency Management Agency's map of areas in Douglas County north of Buckeye Creek has added several areas where previously the maps just stopped.
Combined with the county's efforts to develop a new floodplain ordinance after the old one was declared unconstitutional, residents who want to purchase flood insurance may find themselves paying more.
Community Development Director Mimi Moss told a workshop on the flood ordinance that the new maps add parcels on the east side of the Valley north of Buckeye Creek, including Johnson Lake, Buckbrush and Sunrise Pass washes.
The expense of flood insurance isn't the only cost associated with the new maps and ordinance.
Engineer Kent Neddenriep said getting the maps altered in order to build could cost up to $100,000.
"Twice as many people are affected by the new flood maps," he said. "I think that if everyone knew they were going to be in the flood plain in a year you would have an outcry."
Moss said that if the county was allowed to send every request for an alteration of the flood map straight to the federal government, it would be easy to manage.
"But that's not the way it works," she said.
The county administers the floodplain under an ordinance, which provides residents with a discount on their flood insurance.
However, a challenge to the ordinance by a builder in federal court resulted in the ordinance being overturned. It was already being rewritten after the county received a letter from the Federal Emergency Management Agency saying it was not in compliance. The county plans to host another workshop on the ordinance in June.
An opportunity to comment on the new flood maps is also waiting in the wings. The federal government will open a 90-day comment period on the new flood maps soon.
The ordinance and the new flood maps come together when someone wants to build in the floodplain or tries to purchase insurance.
Building in the floodplain raises the level of flood waters, which can increase the effect on other residents, according to the Carson River Subconservancy.
"Development in the flood plain increases impervious surfaces and removes floodplain storage," Genie Azad told a workshop sponsored by the Carson River Coalition. "What happens here affects downstream users. Filling in floodplain results in raising flood levels."
