Has the Central Sands turned a corner on historic rainfalls that have persisted for the better part of a decade?
In 2020, Hancock came out just a little drier than average (29.5 inches) and Stevens Point just a little wetter (34 inches), according to National Oceanic and Atmospheric Administration preliminary data. Compare this with 2019, when Hancock notched a record 43.4 inches of precipitation – 12 inches above average, and Stevens Point was just shy of the record at 45.4 inches – 13 inches above average.
Not only was 2019 wet, but all years since 2013 – and not by just a little. The Central Sands received way over an extra year’s worth of precipitation during 2014-2019.
A return to normal would be welcome relief to lake and stream property owners whose yards, homes, and cottages have been flooded by high water. But a return to normal would also increase high capacity irrigation well pumping and a renewed drying of pumping-depleted surface waters, such as Long, Huron, and Plainfield Lakes near Plainfield; Fish, Pine, and Bohn near Hancock; Pleasant Lake near Coloma; Wolf Lake near Almond; and the Little Plover River near Plover.
Understanding Historic Precipitation Patterns and What They Mean
A lot can be learned from a look at the region’s precipitation trends over the last 80+ years, and this look is helped if we average annual precipitation over 5-year increments, i.e., 2012-2016, 2013-2017, 2014-2018, etc.
Long term patterns reveal our region came out of 1930s-era drought to precipitation abundance in the early 1940s. But then dry conditions returned with a vengeance and persisted through the 1950s and early ‘60s. Since around 1970 precipitation has generally trended upward, with wet and dry cycles of about 5-10 years. Dry years have become increasingly rare of late – the Central Sands has not experienced a truly dry year since 1989 when precipitation was 20% below average at Stevens Point (less dry at Hancock).
Despite a trend to wetter conditions, something ominous arose in the early 2000s and persisted until the historic rains of the last few years: lakes, streams, and groundwater levels in areas with high densities of high capacity irrigation wells plummeted to near- or all time lows, lower than those of the 1950s drought. In areas of less pumping, such as near Wild Rose and Wautoma, levels dipped a little in 2006 to 2010, but never declined to drought levels. Multiple studies have implicated groundwater pumping as the cause.
What the future will bring, of course, remains to be seen, and it would be reckless to assume recent wet conditions will persist or that 1950s style drought will return. But if Central Sands lakes, streams, and wetlands are to remain healthy, along with the creatures and economy they support, groundwater pumping needs to be managed. A reasonable pumping strategy would be to allow plenty of access when waters are high, and then reduce that access so that lakes and streams are never stressed as they were in highly pumped regions between 2004-2015.