Thaw still distant for Iowa River

RIVER WATCHING is a spring time event across the Midwest at this time of year. Guessers and speculators will attempt to predict when snow melt and water runoff will become sufficient to effect the Iowa River and cause the break up of its present stranglehold on ice. Since every year is different, it is anybody’s guess when an initial advance of warm air will penetrate northward and stay long enough to have a meaningful impact to our landscape. The change over from winter to spring will come. It is inevitable. I’m sure many of the readers of this column will vote for a true mid-winter thaw to at least tell us that spring is just around the corner.

TIMMONS GROVE is one of Marshall County Conservation Board’s earliest acquisitions, a 199 acre parcel of land bought in August 1961. Three Bridges County Park was first in November 1960. This was a new venture for the fledgling members of the Conservation Board at the time. They had been established only a few years prior, on July 1, 1958 after an affirmative positive vote of the people of Marshall County to create the MCCB. Part of the mission of any county conservation board is “to acquire, develop maintain and make available of the inhabitants to the county public museums, parks, preserves, parkways, recreational centers, county forests, wildlife and other conservation areas, and to promote and preserve the health and general welfare of the people, to encourage the orderly development and conservation of natural resources and to cultivate good citizenship by providing adequate programs of public recreation.” So says the opening paragraph of the Code of Iowa Chapter 350.

The MCCB has come a long way and accomplished many things that benefit natural resources, wildlife and the people that use, enjoy and benefit from having public lands to partake in a wide range of outdoor activities. To learn more about what the MCCB has to offer, start with a visit to the Conservation Center at the Grimes Farm. Inside this excellent facility are natural history displays, hands on activities for kids and adults, meeting rooms and the administrative offices of this county department. Informative brochures are available to allow one to read more about any natural resource area that interests them. Check it out now to help prepare for spring when it does come.

Timmons Grove is a floodplain forest of maple, basswood and other pioneer species of trees. As a typical floodplain woodland, it does have the tendency every year to be the recipient of high water from an overflowing Iowa River. That is the nature of flood plains in the first place, to allow expanding waters from a river to dissipate energy over a wide area but at small flow rates compared to the active river channel itself. Within Timmons Grove’s boundaries are ancient crescent shaped river beds many of which are superimposed upon each other. These geomorphological land features are proof of centuries past changes in the course of the river within its broad floodplain. They are best seen right after ice break up after the melting of all surface snow and ice. These old channels become very visible since they are temporarily filled with water.

The entire broad width of the Iowa River floodplain has deposits of silt, sands, gravels and other soil elements that tell a story. The story is thousands of years old and full of past climatic events that overshadow anything we call “normal” today. Plug in your way-back machine to about 15,000 years ago when the Wisconsinan glacial system was beginning its retreat. The entire planet was coming out of its most recent ice age. The climate was entering into a warming phase, an interglacial warm period of time that would take thousands of years to complete. We are still within that interglacial warm zone, geologically speaking.

Prior to glacial melting, a vast region of northern North America was covered with ice from the Seattle area to Maine. Iowa was in the middle and for this region, with a tongue of glacial ice protruded from Canada, the Dakotas and Minnesota. Its southern most point of ice advance is now Des Moines. The eastern edge of the thick glacial ice wedge was near State Center. Most of what we call Marshall County was not under this recent glacial system, but being so close meant the local long range climate and short term weather was very much impacted from icy cold and very strong winter winds. In contrast, during each short but intense summer of glacial times, ice melted and huge amounts of water escaped from the glacier. The runoff helped to carve and locate the river valley systems we know today. The Iowa River was just one of many to see tremendous amounts of water boiling down the valley and filling the entire width of the floodplain. And during this process repeated over thousands of years, water moved soil, sand and gravel into various amounts over the entire width of the floodplain. That is why floodplains are general pancake flat with only minor elevation changes.

Water is relentless and it will find a way out of floodplains. The stream bed we call the Iowa River is a minuscule remnant today, a product of its geological and glacial past. Still it is serving a natural function of draining water off the land. The soils above the river within the entire watershed are the “sponge” to hold water. Water and soil grow vegetation, natural grasses, forests or wetland species in addition to our modern farmland crops.

The next time you go for a hike at Timmons Grove, do recall these historical facts. If that hike is during ice break up, marvel at the power of moving water to push, shove, cut and fill the land along the river. If that hike is during the initial spring green-up of forest floor vegetation, you will be sung to by lots of frogs newly emerged from hibernation. They will be taking advantage of water collected in old river beds, sloughs and depressions of the floodplain. The frogs will not care one tiny bit about past glacial systems. They are just one biological component, one very tiny piece of the web of life puzzle. But you as a human being can understand the concepts of geological time frames of long ago. You can appreciate what the land is telling you about its history. You can read it in the landscape of Timmons Grove.

A BALD EAGLE was observed this past week west of Albion. It was flying. It was carrying a large stick in it talons. The obvious conclusion is that it was taking the stick to its nest. This is entirely within the correct time frame for eagles in early March. At least for the Decorah eagle and the camera watching equipment, nest building is over. Egg laying has begun. A new generation of bald eagles will be watched by millions of people via their computers during the next several months. Check it out. Marshall County had at least four known bald eagle nests last year. There is every reason to believe they will be active during 2014.

DUCKS UNLIMITED, Iowa River Valley Chapter, will host its membership banquet on March 15. The location will be the Impala Ballroom on West Lincoln Way in Marshalltown. Save the date and plan to attend. Wetland conservation needs all the help it can get. DU is one great way to assist in this regard. Call Rich Naughton at 641-328-0124 for tickets. Ducks Unlimited got its start in 1937 during the dust bowl days of a North American drought. Determined not to sit by and do nothing, a group of waterfowl sportsmen joined together to form an organization that became known as Ducks Unlimited. Its mission was and still is: habitat conservation. Wetland habitat is not just for ducks. Habitat enhances life for hundreds of other species and wetland environments help hold water, purify water and moderate floods while reducing soil erosion. Wetlands are one of Nature’s most productive ecosystems. Your help at the DU dinner and banquet will very much appreciated.

Here is a thought for the day: Words that soak into your ears are whispered … not yelled.

Garry Brandenburg is a graduate of Iowa State University with BS degree in Fish & Wildlife Biology. He is the retired director of the Marshall County Conservation Board. Contact him at PO Box 96, Albion, IA 50005.