Nature Rambles | Low water level brings new life



If you have been out along the Illinois River this summer, you might have noticed that the water level has been low for several weeks. When this happens, mudflats become exposed and then something magical happens. Seeds that lie dormant in the mucky soil sprout and send green leaves to cover the earth. The lush green color is striking against the water and blue sky. In large backwater areas of the Illinois River, this verdant carpet can stretch out to cover hundreds of acres of land that were underwater in the spring and early summer.

Areas that have been dry the longest are now covered with numerous species of grasses, sedges and rushes. They reach for the sky and quickly produce seed. They take advantage of this fleeting habitat and hope they can finish their life cycles before the river rises and the waters reclaim the newly exposed land.

The ephemeral nature of mudflat also brings a flush of new habitat for other creatures. Exposed soil now has plenty of oxygen and spurs the growth of nematodes and insects. They, in turn, attract migrating shorebirds. Thousands of birds walk the mudflats on long legs, heads down, with their long beaks probing the soil for food. These birds time their fall migration to take advantage of the low water conditions along our major rivers.

As summer progresses and fall approaches, these backwater areas will become thick and tall with moist-soil plants, all producing seed. Summer drought turns to autumn rain and the next stage in the annual cycle of the river begins. Water returns to the backwater lakes and floods the green fields. The shorebirds have long gone to the Southern Hemisphere, but on their heels comes another traveler. Waterfowl, countless in number, land upon the water. Below their flapping feet are the submerged plants of summer. The seed heads ripe with food for the ducks. The ducks now are the ones with their heads down, below the surface of the water, reaping the harvest of the summer’s bounty.

The Illinois River is a river of riches. The diversity is tied to the fact that our river still has a pulse… a flood pulse. The seasonal nature of flood, then retreat, then flood again is crucial to uncountable species. Some years are better than others. The flood pulse is sometimes out of whack. Last year, we had unseasonable flooding in August. This upset the timing of plants, and many did not grow in the backwaters. Shorebirds didn’t linger on the mudflats that were submerged, moist-soil plants did not grow and produce seed, and waterfowl numbers were low in the fall. But this year, it is shaping up to be an incredibly productive year.

Emiquon Refuge

Looking south over the South Globe unit of Emiquon Refuge accessible from Dickson Mounds Road. (PHOTO BY MIKE MILLER)

If you want to witness the wonders of the Illinois River floodplain, here are a few places to explore. Chautauqua National Wildlife Refuge just north of Havana has had an excellent summer draw-down this year in both the north and south pools. Across the Illinois River from Chautauqua is The Nature Conservancy’s Emiquon Preserve. Because of the success of their new water control structure, they have been able to draw down water levels all summer. Along Dickson Mounds Road, west of highway 87 are the North Globe and South Globe units of Emiquon Refuge, property managed by the U.S. Fish and Wildlife Service. Closer to home, just south of Bartonville, the roadway to Mendenhall Boat Ramp takes you through a natural backwater that is shaping up to be excellent habitat for fall migration. We have numerous areas to explore, so get out there and enjoy it before old man winter takes it over.

1 comment for “Nature Rambles | Low water level brings new life

  1. Theresa McHenry
    August 31, 2018 at 11:38 am

    Great article, Mike. You paint a very vivid picture while educating us. Thanks!

Leave a Reply

Your email address will not be published. Required fields are marked *