Upper Mississippi River Explained

Upper Mississippi River
Source1 Coordinates:47.253°N -95.212°W
Mouth Location:St. Louis, Missouri (flows into the Middle Mississippi)
Subdivision Type1:Country
Subdivision Name1:US, Canada
Length:1,300 miles (2092.147 km) [1]
Source1 Elevation:450m (1,480feet)[2]
Discharge1 Avg:5796m3/s[3]
Basin Size:490000km2[4]

The Upper Mississippi River is today the portion of the Mississippi River upstream of St. Louis, Missouri, United States,[5] at the confluence of its main tributary, the Missouri River. Historically, it may refer to the area above the Arkansas Post, above the confluence of Ohio River, or above Cape Girardeau.

History

In terms of geologic and hydrographic history, the Upper Mississippi east and south of Fort Snelling is a portion of the now-extinct Glacial River Warren which carved the valley of the Minnesota River, permitting the immense Glacial Lake Agassiz to join the world's oceans at the Gulf of Mexico. The collapse of ice dams holding back Glacial Lake Duluth and Glacial Lake Grantsburg carved out the Dalles of the St. Croix River at Interstate Park. The Upper Mississippi River valley likely originated as an ice-marginal stream during the Pre-Illinoian Stage.[6] [7]

The Driftless Area is a portion of North America left unglaciated at that ice age's height, hence not smoothed out or covered over by previous geological processes.

Inasmuch as the Wisconsin glaciation formed lobes that met (and blocked) where the Mississippi now flows, and given that huge amounts of glacial meltwater were flowing into the Driftless Area, and that there is no lakebed, it is assumed that there were instances of ice dams bursting.

Characteristics

The Upper Mississippi from below St. Anthony Falls (Minneapolis, Minnesota) downstream to St. Paul, Minnesota is a gorge with high limestone bluffs carved by the waterfall. Upstream of the waterfall the land slopes gently to rivers edge. Downstream of downtown St. Paul the river enters its wide preglacial valley. The states of Minnesota, Wisconsin and Iowa, along with the federal government, have preserved certain areas of the land along this reach of the river.

There are three National Park Service sites along the Upper Mississippi River. The Mississippi National River and Recreation Area is the National Park Service site dedicated to protecting and interpreting the Mississippi River itself. The other two National Park Service sites along the river are: Effigy Mounds National Monument and the Gateway Arch National Park (home to the Gateway Arch in St. Louis).

Unlike the Lower Mississippi, much of the upper river is a series of pools created by a system of 29 locks and dams. The structures were authorized by Congress in the 1930s, and most were completed by 1940.[8] A primary reason for damming the river is to facilitate barge transportation. The dams regulate water levels for the Upper River and play a major part in regulating levels on the Lower Mississippi.

Ecology

On the upper reaches near the Minnesota-Wisconsin border, the river's floodplain is between 1.5 and 5 kilometers (between 1 and 3 mi) wide. South of St. Louis, Missouri, the alluvial floodplain is approximately 80 kilometers (50 mi) wide. Major tributaries to the Upper Mississippi River include the Missouri, Illinois, Minnesota, St. Croix, Chippewa, Black, Wisconsin, and Kaskaskia Rivers.[9]

The Upper Mississippi provides habitat for more than 125 fish species and 30 species of freshwater mussels. Three national wildlife refuges along the river cover a total of 465 square kilometers (285,000 ac). The largest of them, the Upper Mississippi River National Wildlife and Fish Refuge, is over 420 kilometers (260 mi) long, reaching from the Alma, Wisconsin area down to Rock Island, Illinois. The refuge consists of blufflands, marshes, bottomland forest, islands, channels, backwater lakes and sloughs.[10] It is part of the Mississippi Flyway.

Although the river is much cleaner than it was in recent decades, water quality is still a priority concern. Agricultural runoff, including sediment, excessive nutrients, (particularly nitrogen and phosphorus), and chemicals from agricultural and industrial sources continue to threaten Upper Mississippi River aquatic resources. In addition new threats continue to emerge such as personal care items including pharmaceuticals and endocrine-disrupting chemicals. The five states bordering the Upper Mississippi River are working together to address water quality issues.[11] [12] [13]

There is general agreement that nutrients are contributing to the Gulf of Mexico dead zone and to eutrophication problems in Lake Pepin, a large natural riverine lake that is part of Pool 4 of the Upper Mississippi River. National and regional efforts are addressing these problems, but nutrient impairment problems are occurring elsewhere in the Upper Mississippi River as well, particularly in off-channel portions. Excessive nutrients contribute to thick floating mats of filamentous algae or duckweeds that have a pronounced negative impact on light penetration and may threaten the growth and persistence of submerged aquatic vegetation that is important for fish and aquatic life, including waterfowl. Efforts to control nutrients from point and non-point sources in the basin have aimed to provide additional benefits.[14]

Navigation

See main article: List of locks and dams of the Upper Mississippi River. Navigation locks allow towboats, barges, and other vessels to transit the dams. Approximately 1350 kilometers (850 mi), from the head of navigation in Mile 858, Minneapolis, Minnesota down to Cairo, has been made suitable for commercial navigation with a depth of 2.75 meters (9 ft). The agriculture and barge transportation industries have lobbied in the late 20th and early 21st centuries for a multibillion-dollar project to upgrade the aging lock and dam system. Some environmental groups and advocates of budgetary restraint argue that the project lacks economic justification.[15]

Each lock and dam complex creates a pool upstream of it. There are 29 locks on the Upper Mississippi maintained by the U.S. Army Corps of Engineers—from Upper St. Anthony Falls upstream to Chain of Rocks downstream.[16] The locks provide a collective 123 meters (404 ft) of lift.[17]

Expansion proposals for locks

The Army Corps of Engineers has studied expanding locks 20, 21, 22, 24, and 25 on the Upper Mississippi.[18]

List of pools and locks

Pool Locality Lock Mile marker (km) Distance (km)
USAF Pool align=right 854 align=right 1375 align=right   align=right  
LSAF Pool align=right 853 align=right 1373 align=right 1 align=right 2
Pool 1 align=right 848 align=right 1365 align=right 5 align=right 8
Pool 2 align=right 815 align=right 1312 align=right 33 align=right 53
Pool 3 align=right 797 align=right 1283 align=right 18 align=right 29
Pool 4 align=right 753 align=right 1212 align=right 44 align=right 71
Pool 5 align=right 738 align=right 1188 align=right 15 align=right 24
Pool 5A align=right 728 align=right 1172 align=right 10 align=right 16
Pool 6 align=right 714 align=right 1150 align=right 14 align=right 23
Pool 7 align=right 703 align=right 1132 align=right 11 align=right 18
Pool 8 align=right 679 align=right 1093 align=right 24 align=right 39
Pool 9 align=right 648 align=right 1043 align=right 31 align=right 50
Pool 10 align=right 615 align=right 990 align=right 33 align=right 53
Pool 11 align=right 583 align=right 939 align=right 32 align=right 52
Pool 12 align=right 557 align=right 897 align=right 26 align=right 42
Pool 13 align=right 522 align=right 840 align=right 35 align=right 56
Pool 14 align=right 493 align=right 794 align=right 29 align=right 47
Pool 15 align=right 483 align=right 778 align=right 10 align=right 16
Pool 16 align=right 457 align=right 736 align=right 26 align=right 42
Pool 17 align=right 437 align=right 704 align=right 20 align=right 32
Pool 18 align=right 410 align=right 660 align=right 27 align=right 43
Pool 19 align=right 364 align=right 586 align=right 46 align=right 74
Pool 20 align=right 343 align=right 552 align=right 21 align=right 34
Pool 21 align=right 325 align=right 523 align=right 18 align=right 29
Pool 22 align=right 301 align=right 485 align=right 24 align=right 39
Pool 24 align=right 273 align=right 440 align=right 28 align=right 45
Pool 25 align=right 241 align=right 388 align=right 32 align=right 52
Mel Price Pool align=right 201 align=right 324 align=right 40 align=right 64
Pool 27 align=right 185 align=right 298 align=right 16 align=right 26

See also

External links

Notes and References

  1. Web site: UMESC - About the Upper Mississippi River System . www.umesc.usgs.gov . 4 June 2020.
  2. Web site: General Information about the Mississippi River . U.S. National Park Service . 2006-04-01.
  3. Web site: Background on Upper Mississippi River Basin . EPA: Mississippi River Basin & Gulf of Mexico Hypoxia . 2006-04-01.
  4. Web site: River and Basin Facts . Upper Mississippi River Basin Association . 2009-04-07.
  5. Web site: Mississippi River History, Physical Features, Culture, & Facts. 2020-06-03. Encyclopedia Britannica. en.
  6. Hallberg . G. R. . Pre-Wisconsin glacial stratigraphy of the central plains region in Iowa, Nebraska, Kansas, and Missouri . Quaternary Science Reviews . 1986 . 5 . 11–15 . 10.1016/0277-3791(86)90169-1. 1986QSRv....5...11H .
  7. Richmond . G. . Summation of quaternary glaciations in the United States of America . Quaternary Science Reviews . 1986 . 5 . 183–196 . 10.1016/0277-3791(86)90184-8. 1986QSRv....5..183R .
  8. Web site: About the Upper Mississippi River System . USGS Upper Midwest Environmental Sciences Center . 2006-03-13.
  9. Web site: Basin Facts . Upper Mississippi River Basin Association . 2006-04-01.
  10. Web site: About the refuges . Friends of the Upper Mississippi River Refuges . 2006-04-01 . dead . https://web.archive.org/web/20050403235059/http://www.friendsofuppermiss.org/pages/Refuges.html . April 3, 2005.
  11. Web site: Issues and Challenges- Water Quality . Upper Mississippi River Conservation Committee . 2008-04-11 . https://web.archive.org/web/20071015212057/http://mississippi-river.com/umrcc/issues.html#WaterQuality. 2007-10-15.
  12. Web site: 2007 Water Quality Program Report- Protecting Water Quality through Interstate Cooperation . Upper Mississippi River Basin Association . 2008-04-11.
  13. Web site: Upper Mississippi River Nutrient Monitoring, Occurrence, and Local Impacts: A Clean Water Act Perspective . Upper Mississippi River Basin Association . 2012-03-21.
  14. Web site: Nutrient Impairment Identification in the Upper Mississippi River . Mississippi River Basin Nutrients Science Workshop, October 4–6, 2005 . 2008-04-11. https://web.archive.org/web/20080117073348/http://www.epa.gov/msbasin/taskforce/nutrient_workshop/index.htm#other . 2008-01-17.
  15. Web site: River debate continues . Marcia Zarley Taylor . AgWeb . 8 March 2006 . 2006-03-13 .
  16. There is a Lock 5 as well as a Lock 5A, and there is no Lock 23. Web site: Operation & Maintenance of Navigation Installations (OMNI) Reports . Rock Island District Engineers . 2006-04-27 . https://web.archive.org/web/20060719204859/http://www.mvr.usace.army.mil/mvrimi/omni/webrpts/omni_vl/river_lock.asp . 2006-07-19 . dead.
  17. Web site: U.S. Waterway System Facts, December 2005 . USACE Navigation Data Center . 2006-04-27 . dead . https://web.archive.org/web/20070703141148/http://www.iwr.usace.army.mil/ndc/factcard/fc05/factcard.pdf . 2007-07-03.
  18. Web site: Walker, Brad . Big Price—Little Benefit: Proposed Locks on the Upper Mississippi and Illinois Rivers are not Economically Viable . Nicollet Island Coalition . February 2010 . 2017-07-13.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Upper Mississippi River".

Except where otherwise indicated, Everything.Explained.Today is © Copyright 2009-2024, A B Cryer, All Rights Reserved. Cookie policy.