Two of Salt Lake County Mayor Peter Corroon's most admirable traits are his insistence that Salt Lake County government is accountable to the people and that county residents get the best bang for their tax buck.

The recent discovery that the county is $19 million short on 25 recreation projects seems to defy those standards. Last November, voters approved a $63.5 million bond to start construction on trails and new recreation centers, and to make other capital improvements. Now county officials say that the true cost of the projects will far exceed the bond, due to low-ball estimates and inflation costs.

Inflation costs? Come now. The November election was four months ago and there hasn't been a great economic downturn since. Low-ball estimates may be a more plausible explanation, but it's still difficult to comprehend how cost projections could be off by nearly a third of the value of the bond.

Corroon and the Salt Lake County Council, which placed this proposition on the ballot, need to be held to account for the gross inaccuracies of these projections. After all, voters should have some confidence that the backers of the proposition had firm cost projections before placing the matter on the ballot. Voters should get that for which they agree to pay.

For its part, the County Council passed a resolution assuring cities that the county will not break its promise to pay out the full $63.5 million in ZAP tax that voters approved. The money just won't go as far. The council has not yet determined what to do about the shortfall.

For starters, the County Council needs to insist upon an audit of these cost projections. Were voters promised more than the county reasonably could deliver? How could these estimates be so wrong?

Corroon has recommended that the county use the $20 million intended for the construction of a parking garage at the South Towne Exposition Center to offset the inflationary construction costs of the recreation projects. This would be a simple solution to the county's $19 million shortfall, but the larger issue is the flawed cost projections.

Some projects will cost $6 million to $7.5 million more than previous estimates. County residents deserve a better explanation for these "shortfalls" than "inflation."