(AP) – Federal officials say Stockton Dam in southwest Missouri is expected to begin generating hydroelectric power by early June after an upgrade made to its turbine blades.

In 2009, one of the turbine blades at the dam broke, sending vibrations through the dam’s powerhouse. The turbine was welded back on and put back into service but it was always considered only a temporary fix.

A week ago, the last of seven curved blades – each weighing 17,200 pounds – was successfully attached to a giant metal hub.

Rod Hendricks, operations project manager of the U.S. Army Corps of Engineers dam at Stockton Lake, says it was the first major upgrade to the hydroelectric system since it went into operation in 1973.