Congratulations to LAM1 for the First-to-Find of this Earth Cache... and during Leap Year 2016 weekend too!!!
Michigan was heavily influenced by the Wisconsinan Glacier ice sheet which covered the entire region from 18,000 to 10,000 years ago. Repeated advances and retreats of its major glacial lobes deposited moraines and glacial plains defining the present day geology and topography of the Great Lakes and surrounding states. The Flint River basin was formed by theses same oscillations of the Saginaw Lobe as it advanced and retreated. The Flint River drains 1,332 square miles of South Eastern Michigan encompassing six river valley segments including the Upper South Branch Flint River, Middle South Branch Flint River, Lower South Branch Flint River (which includes the North Branch Flint River and its tributaries), Upper Flint River, Middle Flint River, and Lower Flint River.
The Flint River descends 412 feet in 142 miles from its origin at Horseshoe Lake on the upper South Fork to its confluence with the Shiawassee River. Gradient ranges from 10.04 feet per mile below the city of Flushing to 0.46 feet per mile near the city of Fosters. The mainstream of the Flint River forms in Lapeer County near Columbiaville where the river's South Branch and North Branch come together. From Columbiaville, it flows west through the city of Flint then north to join the Shiawassee River. The Shiawassee, Tittabawassee, and Cass rivers all merge to form the Saginaw River near the city of Saginaw. From there the Saginaw River flows into Lake Huron at Saginaw Bay. All told the Flint River winds its way through Oakland, Lapeer, Genesee, Shiawassee, Saginaw, Tuscola, and Sanilac counties on its way to Lake Huron.
The general hydrology of the Flint River basin is influenced by the make up of glacial deposits and overall watershed development activities including farming, commercial, industrial, and residential land development. An extensive network of drains developed over the years to dewater the land for uses stated above also directly impact the river system.
The upper South Branch Flint River runs mainly through permeable sandy loam and gravel providing for moderate groundwater inflow, keeping water temperatures cool and water flow moderately stable. The remainder of the Flint River and its branches and tributaries run though sections of less permeable clay-rich loam. Groundwater inflow on these sections is generally reduced, water temperature is warmer, and flow rates less stable. Soil types and land use contribute to high surface run off events. The Holloway dam downstream from Lapeer also moderates maximum river flows in this section of the river. Seventy-two percent of Lapeer County is drained by the Flint River and the Lapeer County Drain Commission maintains 325 miles of county drains comprised of 173 distinct county Flint River Assessment drains. Thirty one of these drains are tributaries to the upper South Branch Flint River. All of these factors influence the health and seasonal flow rates of the Flint River and contribute to the frequent flooding that can be observed at the cache site.
As a side note, the Indian name for the Flint River was Pewonigowink meaning “river of fire stone” or river of flint. Folklore also claims Lapeer was derived from the naming of the south branch of the Flint River, which flows along the eastern edge of the namesake city. The name "Lapeer" is a said to be a corruption of the French word la pierre, which means "the flint". French and Indian traders frequently passed through this section of the river ultimately naming the city for the stone that lay at the river bottom.
To Log this Earth Cache visit the posted coordinates and email me the answers to the following questions. Please do not post your answers in the log or your post will be removed.
Questions:
1. Describe the river conditions near the Cache location during your visit.
2. What time of the year is it? How can this help explain the conditions you find on the river?
3. What do you think causes the flooding in the park where this Earth Cache is located?
4. Where does the Flint River originate?
5. What is the average gradient of the Flint River?
6. Bonus (not required): Name one of the drains that flow into the Flint River or one of its creeks.
7. Another bonus (not required): Post a picture of the River or surrounding city during your visit.
This Earth Cache was posted with the permission of the Lapeer City Parks Department.
References for this Earth Cache include:
https://en.wikipedia.org/wiki/Flint_River_(Michigan)
http://www.michigandnr.com/PUBLICATIONS/PDFS/ifr/ifrlibra/special/reports/sr27/SR27text&tables.pdf