Last week, we began observing the twenty year anniversary of the floods of 1993 that caused much destruction in Iowa. From the standpoint of Marion County Conservation looking back, the flooding in ‘93 created a lot of cleanup in the Lake Red Rock area, as well as a strain on financial resources. While the rain itself created a lot of problems with erosion and road flooding, the rise of Red Rock and the consequent opening of the dam gate contributed to flooding concerns as well.
During the summer of 1993, the gates on Red Rock dam were opened for only the second time in history. One week in the summer of ’93, the outflows from the lake were increased from 30,000 to 35,000 and then to 40,000 cubic feet per second (Journal Express). At the start of the week, the U.S. Army Corps of engineers had reported a plan to hold the lake at the release rate of 30,000 cfs, but they also anticipated more rainfall that could cause “much larger outflow increases” (Journal Express).
Though the Corps had hoped to keep the outflow at 30,000 cfs, their prediction was also accurate; the very next week, Lake Red Rock continued to break records as the dam outflow was increased to 65,000 cfs one day and then to 70,000 cfs the next (Journal Express). Former Sheriff Marv Van Haaften recalls the dam’s increased outflow as an intimidating experience to all who experienced it. “The ground literally shook across the dam,” Van Haaften remembers. “Waves splashed up over the side of the dam.”
Lake Red Rock continued to break and set new record levels in weeks to follow. A couple of weeks after the outflow was increased to 70,000 cfs, Lake Red Rock finally crested at 782.62 feet above sea level, and the outflow was “being held steady at 103,000 cfs” (Journal Express). The U.S. Army Corps of engineers released advisories to Marion County residents, reminding them that Lake Red Rock had been experiencing “uncontrollable flows” from the Des Moines river, and they strongly recommended that boaters cease to use Lake Red Rock during that time because of whirlpools and hazardous currents (Journal Express). Both boat ramps were closed as well.
Van Haaften states of the floods, “Obviously it was a scary time, and we hope it never happens again.”