MADISON, Wis. — A lot of rain — but maybe not as much as you think — fell Aug. 20 on the shallow, 281-square-mile basin of land that drains into Madison's lakes Mendota and Monona. Most of the 12- to 15-inch deluge that drenched parts of western Dane County flowed away from Madison toward the Wisconsin River. Only about 4 inches fell across the lakes' watershed, according to the National Weather Service. Every year, there's a 1-in-10 chance of a similar rain. But that 4 inches swelled Madison's lakes enough to flood streets and homes, and to prompt worries of a dam break that could have been devastating for the densely populated Isthmus and areas around Lake Monona, the Wisconsin State Journal reported. How could 4 inches of rain cause so much trouble? The answer lies in a decades-old dispute — now being revived — about how much water Lake Mendota should hold and how much higher than the Isthmus the big lake's water level should be maintained. The Tenney … [Read more...] about How could 4 inches of rain cause so much Wisconsin flooding?