On the Horizon is a New Glarus 360 feature looking beyond today’s headlines at larger economic, demographic, technological and cultural changes that may eventually reach our community. The goal is not to predict the future, but to recognize consequential changes while they are still far enough away to prepare for them.

When a heavy rain event settles over the hills west of New Glarus, the water begins moving long before anyone sees it at a storm drain. Some soaks into farm fields, lawns and wooded slopes. Some collects in shallow swales, roadside ditches and culverts. Some moves toward what locals know as Durst Valley, through the village and eventually toward the Little Sugar River. None of that is new. What is changing is how precisely engineers can now measure the landscape, calculate the rain falling on it and model where the water goes next.

That matters because Green County is already wetter than it was generations ago. The Wisconsin State Climatology Office says annual precipitation in Green County has increased 0.83 inches per decade since 1950 — roughly one additional inch every 12 years. The increase has occurred in every season.

The more consequential change for streets, culverts and storm sewers may not be the annual total, but how much water arrives at once. Wisconsin Department of Natural Resources data, drawing on projections from the Wisconsin Initiative on Climate Change Impacts, says the frequency of 2-inch rainfall events is projected to increase about 30 percent, while 5-inch rainfall events could nearly double. A few extra inches spread over months is one thing. Several inches falling in hours is another.