CEDAR RAPIDS, Iowa — People who voted yes and no two weeks ago have been calling City Council members to encourage a new vote on a sales-tax extension that shortens the period of the tax and focuses it all on flood protection, Mayor Ron Corbett said on Wednesday.

Corbett, though, told The Gazette editorial board that it didn’t make sense to rush into any decision about a new vote without some “hard data” that might help show what voters didn’t like about the May 3 ballot and what might make some change their mind on a new vote.

Corbett said members of the Protect Cedar Rapids Committee, which pushed for the passage of a sales-tax extension for 20 years for flood protection, street repairs and property-tax relief, are talking about using leftover campaign funds to conduct a scientific survey of residents to assess why people voted for and against the tax.

Corbett said individuals have provided plenty of theories about why the sales-tax extension went down to defeat by 221 votes — out of some 32,000 cast. But without data there’s no way to know what people were thinking, he said.

He said different groups in the community are discussing a citizen petition drive to encourage the City Council to seek a new election on a sales-tax extension for flood protection.

People who voted on both sides of the extension want flood protection, the mayor said.

Corbett said the city’s “preferred” flood protection plan — put together over four months of expert study and citizen input in 2008 and backed by two mayors and City Councils of differing compositions — is a plan with no frills. It isn’t going to change, he said. He said it is nothing but the basics — earthen levees, permanent flood walls, removable flood walls in the downtown and at Czech Village, pumps and gates.

What citizens are suggesting and what the City Council is open to changing is the ballot language on how the tax revenue is used and for how long, he said.

The May 3 referendum called for 50 percent of the local-option sales tax revenue over 20 years be used for flood protection, 40 percent for street repairs and 10 percent for property-tax relief.

Corbett speculated that a new vote could raise a similar amount of money in nine and half years for flood protection if all the revenue from the measure went to flood protection.

State law allows elections on special city issues only four times a year: March, May, August and during the general election in November.

Corbett said November might make the most sense so the community would know before the next state legislative session if it makes sense to lobby state lawmakers to help pay for Cedar Rapids’ flood-protection system. State lawmakers aren’t going to commit any money unless they know Cedar Rapids is going to provide local matching funds, the mayor said.