CEDAR RAPIDS — Partial flood-insurance coverage for at-risk city-owned properties will cost more than $1 million in the next year, an amount that prompted City Council members last night to bemoan the fact that residents have twice turned down an extension of the local-option sales tax to help pay for a flood protection system.

Justin Shields said the ongoing annual expense of flood insurance represented another reason Cedar Rapids needs a flood-protection system. But he said that aspect of the issue was lost in the debates before the sales tax’s close defeats, in May 2011 and this March.

Shields said the city now is facing a “never-ending drain” of flood insurance costs, which he called “a slippery slope we’re on that I’d like to get off.”

“It goes on and on,” he said.

Mayor Ron Corbett said the city is in “the same boat” as homeowners at risk for flooding, who will pay on average $1,200 extra a year for flood insurance on their properties without a new protection system.

“Until we get flood protection, we’re going to be confronted with this issue of how much insurance we should buy every year,” the mayor said.

A flood protection system would reduce the need and cost for flood insurance, Casey Drew, the city’s finance director, said in answer to questions from council members.

Drew called the level of flood insurance that the council approved last night “a starting point,” saying it still left the city open to exposure if public buildings were hit by another a flood of the magnitude seen in June 2008.

The council last night agreed to spend $1.11 million for an insurance premium that provides $25 million in excess flood insurance for the period from Dec. 1, 2012, through Nov. 30, 2013.

This coverage is in addition to the city’s required purchase of basic flood insurance for 49 properties through the National Flood Insurance Program. That program provides building-by-building coverage of up to $500,000 in damage to each building and up to $500,000 for each building’s contents. It represents a total of $19.524 million of coverage at an annual cost of $85,498.

The city could be facing much higher required costs if had not obtained a partial flood-insurance waiver from the federal government. However, the waiver requires the city to both buy basic coverage through the National Flood Insurance Program and to spend at least one-third of 1 percent of its total annual operating budget — or about $425,000 — on premiums for extra flood insurance, Drew has said.

The decision to buy $25 million of extra coverage for a premium of $1.11 million in the next year left the city “somewhere here in the middle,” balancing some level of coverage with a bearable if unpleasant premium, Corbett said.

He pointed out that the city has spent some $35 million to renovate just one flood-damaged property, the Paramount Theatre.

Council member Chuck Swore said he hoped the reality of the expense of flood-insurance coverage would make the public think again about a sales tax to help build a protection system. Swore said Cedar Rapidians historically have not liked the local-option sales tax, but he argued that it makes sense to have some part of the cost paid for by people who shop here but live outside the metro area.

In the short term, the City Council has only the revenue from property taxes to use to pay for flood insurance — which Swore predicted will result in residents saying, “My goodness, you’ve raised my property taxes.”