The Federal Emergency Management Agency (FEMA) is in the process of recalculating flood plain boundaries in Polk County using new technology that provides twice the elevation detail than previous methods. For the 100-year flood plain map in Crookston, it means that some properties that were outside the flood plain on the old maps might now be located within the boundary, and vice versa.

"It's really parcel-dependent relative to whether or not it's good or bad news for someone," City Administrator Aaron Parrish explained. "You might have been in and now you're out, or you might have been out and now you're in and subject to flood insurance requirements."

After attending a meeting where he was brought up to speed on the new technology and maps, Community Development Director Mike MacDonald updated members of the city Ways & Means Committee this week. Up until now, topography was measured in two-foot intervals. With the new technology, he explained, the "contour interval" is half that, which, in theory, makes the elevation data twice as detailed.

"It's significant when it comes to the delineation of what's in and out of the flood plain," MacDonald said. "It's significantly more accurate than what was used for the (FEMA letter of map revision) that was just processed for our first flood control project."

Complicating matters, Parrish said, is the fact that Crookston, throughout all the technological advances, continues to work toward community-wide protection from 100-year flood events. "And while we're working through these projects we're updating maps throughout," he said.

The last major flood plain map revision was done about 30 years ago, Parrish added. "That's the level this latest change is on, so it's a pretty significant deal," he said.