Science Explanation. English. American. Midwest
Description
Vocal Characteristics
Language
EnglishVoice Age
Young Adult (18-35)Transcript
Note: Transcripts are generated using speech recognition software and may contain errors.
The mighty Mississippi river drains a third of America. Nearly every drop of water that falls in the Upper Midwest that isn't either evaporated, absorbed from an aquifer or used by the ecosystem eventually runs its way into this massive river. This kind of area where all the water drains into one basin. A river is called a watershed, but there are smaller watersheds too like a nesting doll. Smaller watersheds fit inside larger watersheds within the Mississippi watershed. We find the Cedar River watershed which holds our local dry run creek watershed. In order to understand the dry run creek watershed, we should first explore our local landscapes and geology. The bedrock of the dry run creek was formed during the Saurian and Devonian periods about 400 million years ago. During this time, Iowa was underwater in a warm shallow sea. This is why we find ocean life preserved its fossils in a lot of Iowa's bedrock. These fossils serve as clues to what Iowa was like in the past part of why the fossils are so well preserved. Is that warm shallow seas are the perfect setting for limestone to form limestone. Is a rock mostly made out of calite and sometimes dolomite or dola stone. These limestones are quickly dissolved by acid and over a long enough timescale rivers dissolve them too. In addition to the limestone, some of the bedrock is made up of sandstone from the Cambrian age beaches that were once here. Most of Iowa's bedrock is usually buried. Unless you're driving past a quarry or a very deep construction site. You probably won't see it. All of the geology you can easily see and explore is our surficial geology. The DRC watersheds surficial geology has been heavily influenced by glaciers. Glaciers crept across Iowa many times over the last 2 million years, but haven't been back in Iowa in the last 11,000 as these glaciers which can be thousands of meters thick and weigh over a billion pounds, move across the land. They broke up some of our bedrock. This broken bedrock served a sediment and as the glaciers moved into Iowa, they carried similar sediment from Canada and Minnesota into Iowa. These sediments continued to break down and helped prairies develop the soil that makes Iowa so fertile today. The movement of those glaciers tens of thousands of years ago even impacts our water quality. Today, in our bedrock are aquifers that still contain some water that seeped through the ground as the glaciers melted. Because of this, the groundwater underlying the dry on creek watershed is deep and clean when conditions permit some rain flows through our soils. And into the same bedrock mixing with this glacial water. Since most of our glacial settlement is a jumble of different sizes. Water flowing through our soils moves relatively quickly. Refilling our aquifers a little faster than other parts of the country. Before the water gets to our aquifers, it passes through our soil. Dry run creek is mostly made up of a few different kinds of loam. Loam is a kind of soil that has roughly equal parts, sand silt and clay. The well mixed sediment helps to make DRC soil perfect for both farming and filtering. So some of the water soaks into the ground and some of it flows over our land through dry run Creek. This doesn't mean we can rely on the lome and underlying limestone entirely. We have to care for our land soil and water both above and below ground. In the past, we've sometimes harmed the waterways. The DRC has historically been used to store coal which can still be found occasionally in and around creek banks. Today, we see two big issues. The first is fertilizer runoff which feeds harmful bacteria in the river. The other is urban runoff. As we've built new roads and sidewalks, water that would have once slowly drifted into our soil is now deflected into the DRC at a much higher rate which is deteriorating our soil between our bedrock glacial sediment loamy soils and modern pollutants. The chemistry of the DRC is constantly changing. We can't really change what the bedrock does, but we can ensure that best management practices, keep our soils intact, prevent pollutants from entering the stream and keep our environments and communities in good health. Our streams and rivers are amazing places to learn from play and, and enjoy so we must protect them. This video was paid for by the Black Hawk County Soil and Water Conservation District with the help of these sponsors. It was made in collaboration with the University of Northern Iowa and edited by Rowan mccarthy to view our other videos in this series, click the thumbnails on the screen now links in the description or visit www dot black Hawk sw CD dot org slash dry run creek.