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Sherburne County Multi -Hazard Mitigation Plan, 2020 Table 21. Historical Flood Crests for USGS Gauging Stations in Sherburne County Historical Flood Crests for Mississippi River at St. Elk River near Big Lake Cloud 4/16/1965 io.86 4/10/1952 10.36 5/7/1912 10.10 4/io/i969 io.o8 6/16/1984 9.87 4/27/2001 9.43 4/7/1997 9•02 4/5/1916 8.6o 4/4/1943 8•04 4/11/1951 7.68 Source: USGS Flooding and Climate Change As Minnesota's climate changes, the quantity and character of precipitation is changing. Average precipitation has increased in the Midwest since 3.9oo, with more increases in recent years. The Midwest has seen a 45% increase in very heavy precipitation (defined as the heaviest i% of all daily events) from 3.958 to 2011 (National Climate Assessment Development Advisory Committee, 2013). This precipitation change has led to amplified magnitudes of flooding. Increased precipitation may also show seasonal changes, trending toward wetter springs and drier summers and falls. An example of a recent year with this character was 203.2, when many MN counties were eligible for federal disaster assistance for drought, while others were eligible for flooding, and seven were eligible for both in the same year (Seeley, 203.3). In 2007, 24 Minnesota counties received drought designation, while seven counties were declared flood disasters. In 2012, 55 Minnesota counties received federal drought designation at the same time ii counties declared flood emergencies. In addition, the yearly frequency of the largest storms —those with three inches or more of rainfall in a single day — has more than doubled injust over 50 years. In the past decade, such dramatic rains have increased by more than 7% (MN Environmental Quality Board, 2014). Southeastern Minnesota has experienced three i000-year floods in the past decade: in September 2004, August 2007, and September 2010 (Meador, 2013). The 2004 flood occurred when parts of south- central Minnesota received over eight inches of precipitation. Faribault and Freeborn counties received over io inches in 36 hours. The deluge led to numerous reports of stream flooding, urban flooding, mudslides, and road closures (MN DNR, 2004). During the 2007 event, 15.10 inches fell in 24 hours in Houston County, the largest 24-hour rainfall total ever recorded by an official National Weather Service reporting location. The previous Minnesota record was 3.o.84 inches in 3.972. The resulting flooding from Page156