Mason City leaders last night approved the first step in requesting flood control aid from the U.S. Army Corps of Engineers. Heavy rain in May caused myriad problems with sewers, the levee on the Winnebago River and a flood home buyout program. Mason City’s flood plain manager Tricia Sandahl says Corps officials inspected the city’s levee system and raised concerns. The height of the levee is a concern, along with its stability. Sandahl says the biggest concern is the height, but the location of a couple of city buildings makes that a very tough issue to tackle.The water treatment plant and the operations and maintenance facility are both on the west side of the levee and raising the height could push water from the river into those facilities and compound the city’s problems. Sandahl says a federal study would be the best thing to do now.If the Corps gets involved, the process would go through four phases. Sandahl says the first phase would be a recognizance study, then a feasibility study, then the Corps would make designs, followed by construction or repairs to the levee itself. If the studies are conducted, it will be five-to-seven years before any improvements to the levee are completed.