VINTON - When tornado sirens sound in Vinton, residents in the northwest part of town can take shelter in what an architect described as a "bulletproof concrete tank."
The Benton County community is among several in Iowa developing tornado-proof safe rooms. Vinton's $386,000 bunker has been completed and was dedicated May 1.
Interest in safe rooms has grown since a May 2008 fatal tornado in Parkersburg. In many cases, the safe rooms are developed in schools or other public buildings, with state and federal funds covering up to 80 percent of the cost for communities, schools or other government entities.
In this photo, The new Vinton community shelter is built into a hill, with a tornado shelter in the basement, in Vinton.
In Linn and Johnson counties, several safe rooms are in various stages of development, according to the Rebuild Iowa Office.
"We hoped we never have to use it," Vinton city coordinator Andy Lent said about the 320-person shelter. Surrounded by low- and moderate-income housing, apartment complexes and a mobile home park, the Donald J. Martin Community Shelter will serve residents in a part of town where many people don't have basements.
In Palo, a safe room that will double as a gymnasium will accommodate about 1,000 people. It will be part of the new city hall and library complex, said city official Tom Watson.
At Wickiup Hill Outdoor Learning Center, a safe room has been included in expansion plans. The safe room, which will be used for administrative offices, will accommodate 200 people, said Dennis Goemaat, deputy director of the Linn County Conservation Department. The center is host to busloads of student visitors, often during the spring tornado season.
Essentially, a safe room is a concrete bunker, said Brad Lang of Solum Lang Architects in Cedar Rapids. He's working with Palo and other communities on safe-room development.
In this area, Lang said, they must be built to withstand at minimum an F4 tornado, which has wind speeds of 207 to 260 mph and could level well-constructed houses, throw cars some distance and turn flying debris into large missiles. Walls must withstand a 2-by-4 fired at 250 mph. Palo's will be constructed to withstand an F5 tornado.
Typically, safe rooms have 12- to 16-inch-thick precast concrete walls and large footings that act like anchors to prevent a tornado from sucking the building out of the ground, Lang said.
The city hall and library portions of the building will not be built to those standards.
"We joke that the politicians can blow away," Lang said.
Entries are recessed or behind L-shaped walls for protection from flying debris.
In Vinton, Lent said, the city didn't try to dress up the safe room. It's essentially the walkout basement of an enclosed park shelter. In Palo and at Wickiup Hill, where the safe rooms are part of structures that will get everyday use, plans call for brick to be incorporated into the concrete walls. The nature center building has windows with reinforced shutters that can be closed in the event of a tornado.
If typical construction costs run $150 per square foot, safe rooms can cost three times that, "not because it's pretty, but to keep you safe," Lang said.