Flash Flood in Wisconsin, June 21, 1997

Flash flooding occurred in southern Ozaukee county as a result of heavy rainfall amounts in excess of 8 inches over a 30 hour period ending about 1200CST. This flash flooding was greater than a "100 year rainfall" based on rainfall frequency maps. No one was injured or killed by the flood waters, thanks to superb rescue efforts by local law enforcement officials and firefighters. Besides public sector damage in county/city parks, there was widespread private and business damages. The hardest hit areas were the cities of Mequon and Thiensville, a small area about 2 miles southwest of Fredonia, and east of Cedarburg. By mid-morning much of downtown Thiensville was issentially a functional lake. (On July 7th, Ozaukee county was officially declared a Federal Disaster Area, making county residents and business owners elgible for Federal disaster aid).It is estimated that there was about $5.2 million in residental/business damage covered by flood insurance policies. This amount is not included in the $3.6 million in property damage listed for Ozaukee county in this report.Areas along and near the Milwaukee River experienced moderate to major damage to homes and businesses. Hundreds of homes and businesses in southern Ozaukee county had significant damage to basements and personal property. Overa dozen homes in Mequon had collapsed basement walls. Hundreds of customers lost electrical power, natural gas, or telephone service. Many people were forced from their homes until repairs or cleanups could be completed. Some car dealerships and repair shops suffered damage to new and used vehicles. The loss of electrical service prevented the use of sump pumps in may homes, which compounded the flooding problems.Many roads and underpasses across the southern part of the county were flooded with several feet of water, resulting in road closures. Some drivers had to be rescued after their vehicles were swept away by deep, fast water currents over roads. Several roads in the southern part of the county had sections of asphalt washed away.Rainfall totals for the 30-hour period ending 1200CST were about 8.50 inches in the extreme southern part of the county along the county line. Other totals included 6.25 inches near the Mequon city hall, 3.09 inches at Cedarburg, 3.08 inches in Waubeka, and 2.26 inches in Port Washington, which experienced a disastrous 100 year flood 1 year ago when over 11 inches of rain fell in a 3 day period.