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The Great Flood of 1993. Mississippi River at St. Louis - Normal Flow. Mississippi River at St. Louis - 1993 Flood. Before. During. Floods. Where does the water come from? Rain Snow Glaciers Where does the water go? Rivers and river systems – watersheds. WATERSHED.
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Before During
Floods • Where does the water come from? • Rain • Snow • Glaciers • Where does the water go? • Rivers and river systems – watersheds
WATERSHED • Land from which water runs off into a stream. • Tributary – feeder stream that flows into a main stream. • Example – Illinois River into the Mississippi River • Distributary – a smaller stream flowing out of a larger stream. • What separates watersheds • Divides + =
Mississippi River - Controlled • Levee – natural and/or constructed ridge or embankment designed to prevent a river from flooding onto its floodplain? • Floods occur when water flows over or breaks through a levee