The long-contested plan to remake North Adams’s flood control chutes has cleared its final state permitting hurdle, ending an argument that has run, in one form or another, since the concrete was poured in the 1950s.

The approved design removes a portion of the channel walls and restores a floodplain along a stretch of the Hoosic, while retaining hard protection where the river runs closest to downtown buildings.

Neither the engineers who wanted the chutes kept nor the advocates who wanted them gone entirely got what they asked for. “That is roughly what a compromise looks like,” said one member of the river commission, “and it took us twenty years to write it down.”

Construction is expected to begin after the spring melt.