‘Rain, rain go away and come again some other day,” are words from a nursery rhyme I remember singing as a child. Maybe I was more aware of the weather as a child because our daily farming routine was determined by the forecast. I do remember the Mississippi River flood of 1965. It was the spring following a nasty cold winter with way too much snow. It seemed back then the only time the Mississippi River flooded was in the spring when the winter snows began to melt. More recently we have had floods spoil 4th of July celebrations and events into August.
Summer floods of course are due to heavy rainfall here and on our neighbors up north. We can watch a storm develop and roll across the state on color-coded radar we did not have back in the 1970s. We see and hear the lightning and thunder and feel the rain, but when a storm hits we may not realize the magnitude of a single weather system. The volume of water that falls from the sky is unbelievable.
Here are some numbers that will surprise you. Let’s start small. One inch of rain falling on a small garage 20 by 20 would fill five 50-gallon rain barrels or 250 gallons. Let’s go a little bigger and say your house and driveway have a surface area of 60 feet by 60 feet. One inch of rain would equal 2,244 gallons of water. Hopefully your flower beds, trees and lawn soak some of that into the ground. If not, the runoff from your home and your neighbors would fill storm sewers in a short time. All that water rushes toward creeks, steams and our Mississippi River.
The same storm dropping one inch of rain on an acre of land would equal 27,154 gallons of water or 679 (40 gallon) baths. That’s a lot of bubble baths. Rain on one square mile of land would hopefully soak up 17,378,560 gallons of water. In one square mile, the five inches of rain that fell and flooded property in July on the south side of Clinton would have been five times 17,378,560 gallons, a number way too big for my little hand-held calculator.
Green space does make a big difference in the amount of runoff by slowing the flow of water enough to allow some to soak into the soil. Trees not only slow the run off but also help filter the water as it seeps into the underground aquifers. Dry creeks in the landscapes help slow erosion, and rain gardens help capture excessive water from heavy rain storms. A great example of a rain garden is in front of NelsonCorp Wealth Management on 13th Avenue North across from Medical Associates. Runoff from the building collects in the dry pond area, giving the water time to slowly soak into the soil and not flood the busy intersection. Plants in the pond can tolerate wet soil for short periods of time.
Several years ago when the Lyons District put in the new streetscape, they used a water permeable brick that allows the rain water from the sidewalk to be absorbed into the ground and not run off into the storm sewers. This is more “Earth friendly” and a natural way to help water the new trees planted along the sidewalks.
There are simple things you can do in your yard and around your home to use and conserve the rain that falls from the sky:
n Check and clean your gutters on a regular basis.
n Angle your downspouts to water a large tree, shrubs or a garden.
n Install a rain barrel to collect water for spot watering during the heat of the summer.
n Incorporate a dry creek or rain garden to your landscape if possible.
n Plant trees, shrubs and anything green to take up and filter ground water. Any or all of these are earth friendly ways to better use rain water.
Margo Hansen is the director of programs at Bickelhaupt Arboretum in Clinton.