Photo credit: soozbot (Flickr)
The extremely wet rainy weather we’re experiencing this spring may have once been exceptional, but not anymore. The Upper Midwest has experienced a 37% increase in the amount of precipitation falling in very heavy events from 1958 to 2012. The MPCA and Minnesota’s meteorological communities see this as our new reality — climate data as well as future projections indicate increases in very heavy precipitation in Minnesota will continue.
Heavy precipitation events, storms and flooding have significant impacts on Minnesota’s communities and ecosystems. This includes effects on water and soil resources, agriculture, drainage infrastructure, human health, stormwater management, solid waste management and wastewater.
Some of the impacts we are seeing right now or can expect to see:
Cropland runoff pollution
Extreme weather events will impact Minnesota agriculture. Intense rainfalls can mean intense, high velocity runoff of fertilizers, pesticides and sediment into our rivers and streams — particularly from agricultural fields that do not have best management practices in place.
Sanitary sewer system failures
Higher peak intensity rainfall events may result in bypass of wastewater treatment facilities or sanitary sewer overflows, leading to the release of minimally treated or untreated wastewater into lakes, rivers or streams. Sewage plants were designed to take on less water than what we’ve been seeing during the last several years, leading us to believe that bypass events will continue to happen when these rain events occur.
Stormwater system overloads
Changes in amount, frequency and intensity of precipitation impact stormwater management, potentially exceeding the design capacity. These additional pressures on the state’s drainage infrastructure can result in events like the 2012 Duluth flood.
Clearly, there are challenges ahead to protect our communities and ecosystems as these major weather events continue. With the increase in extreme rainfall in Minnesota, it’s only a matter of time until the next heavy rainfall event challenges a Minnesota city and our environment.