A slough is another word for a wetland which acts as a buffer for water run-off from agricultural land and residential and industrial development. Most wetlands (sloughs) in Minnesota and other northern states were formed when the last ice age ended about 10 to 12 thousand years ago. The glaciers helped to create these wetlands when large blocks of ice left behind by the receding glaciers formed dents or small depressions in the ground. These depressions filled with the glacial meltwater and eventually filled with other water from precipitation or other waterways.
The Lake Florida Slough was formed this way and continues to be filled by water from Shakopee creek which flows through the slough on its way to the Chippewa River. This glacial creation next to Lake Florida has been a wonderful benefit to the lake. Sediment carried by the creek and any other groundwater runoff settles in the slough before entering Lake Florida. The slough also allows Lake Florida to "breathe" by creating an outlet and preventing lake stagnation. The sediment in the slough creates an environment for growing aquatic plants like cattails. Cattails filter runoff, reducing nutrients that could harm the lake. Cattails also prevent erosion and provide important habitat for many species of wildlife and birds.
So for the sake of the lake and many species of birds and wildlife, it's not just a slough! It's an original gift from the glaciers that does its job of creating habitat and trying to keep our lakes and waterways clean! To get credit for this earth cache, answer the following questions:
1. Looking west, estimate the distance across the slough.
2. Walk to the end of the piece of land that runs along the waterway that connects the slough to Lake Florida. Compare the water quality of Lake Florida with the Lake Florida Slough. Explain why there is a difference, if any.
3. Explain why the slough is a great benefit to Lake Florida.