‘Normal is relative’ for rain total in watershed district

While the “Normal is Relative” bumper sticker given to Dawn Doering, information and education coordinator of the Coon Creek Watershed District, was tongue-in-cheek, the saying rings true for the area’s water resources.

“While the 2012 total of 31.95 inches within Coon Creek Watershed District area was just 3 percent from normal – the 30-year average of 30.93 inches – when we got the precipitation was anything but normal,” Doering said.

The “faucet” was turned full on in the first half of 2012… and suddenly turned off come August, she said.

According to Tom Gile of Coon Creek Watershed District (CCWD), May was the wettest May on record with eight to 11 inches, depending on location within the Coon Creek Watershed District boundary.

That’s one-third the yearly total in one month and beat the previous record set in 1906 by 1.5 inches, Gile said.

Then March-July was the fifth wettest since 1900 for that five-month period, he said.

“During the growing season, May-September, we received 20.81 inches of rain,” Gile said.

“The annual growing season average is 19.44 inches, a variation of only 7 percent from normal.

“Of the 20.81 inches, more than 16 fell in May and July alone.”

Although flash flooding can occur with such intense downpours, this was welcome relief from the previous dry fall in 2011 when the “faucet” had been turned off in August, according to Gile.

But then fall 2012 became a repeat of 2011 – very dry, Gile said.

The total rainfall for August and September was just 1.3 inches, only outdone by the 0.81 inches received in August and September of 1969, he said.

“Add October 2012, and you get 3.7 inches, still the third driest total for these three months since 1900,” Gile said.

The Coon Creek Watershed District has been tracking precipitation to record what is happening locally to aid in monitoring storm events, soil moisture and wetland hydrology, according to Doering.

This helps in planning for water conservation, flood prevention, water quality issues and groundwater recharge, Doering said.

And, it helps in budgeting, such as for operations and maintenance costs, she said.

Although the 2012 total amount was close to the 30-year average normal, the rain pattern set records for wettest and driest periods, within weeks of each other, according to Gile.

“There you have it… one more ‘normal’ annual precipitation year,” Gile said.

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