region M Area 103 larger picture

Central Iowa and Minnesota Till Prairies

Area is in Western Lake Section of the Central Lowland Province of the Interior Plains.
The area is called the 'Des Moines Lobe of the Wisconsin-age ice sheet.

Area includes portions of the following states:
56% in Minnesota
44% in Iowa

Total Land Area 27,640 square miles (71,630 square kilometers).

Towns/cities include:
Mankato, Marshall, Hutchinson, Minneapolis, and Willmar, Minnesota
Des Moines, Ames, Carroll, and Fort Dodge, Iowa.

Numerous State and county parks and public access areas are throughout the MLRA.

Geology

Paleozoic bedrock sediments, primarily shale and limestone, underlie the glacial deposits in most of the area. Some Precambrian Sioux Quartzite is exposed on the western edge of the area, in southwestern Minnesota.

This area is covered with glacial till, outwash, and glacial lake deposits. Recent alluvium consisting of clay, silt, sand, and gravel fill the bottoms of most of the major river valleys.

It is mostly on a young, nearly level to gently rolling glaciated till plain with moraines and glacial lake plains in some areas. The eastern part of the area has some higher hills (moraines). Natural lakes, marshes, and potholes occur throughout the area.

Topography -

Elevation ranges from 985 to 1,315 feet (300 to 400 meters). Relief is mainly less than 10 feet to 20 feet (3 to 6 meters).

Some of the major valleys are 165 feet (50 meters) or more below the adjoining uplands.

Climate

The average annual precipitation in most of this area is 23 to 35 inches (585 to 890 millimeters)
Most of the rainfall occurs as high-intensity, convective thunderstorms during the summer.
The average annual temperature ranges from 43 to 50 degrees F (6 to 10 degrees C).
The freezefree period averages about 175 days and ranges from 155 to 200 days.

Major Hydrologic Unit Areas

Name Code Extent*
Minnesota (0702) 35%
Des Moines (0710) 32%
Upper Mississippi-Iowa-Skunk-Wapsipinicon (0708 ) 14%
Mississippi Headwaters (0701) 11%
Upper Mississippi-Black-Root (0704 ) 4%
Missouri-Little Sioux (1023) 4%

* this is the percent of area drained by each named hydrologic unit

The major rivers that drain the area include the Blue Earth, Boone, Cottonwood, Des Moines, Lizard, Minnesota, and Raccoon Rivers.

The Minnesota, Crow, and Cannon Rivers are National Wild and Scenic Rivers in this area.

Water

Estimated withdrawls in this MLRA:
Public supply surface water 9.5% ground water 8.9%
Livestock surface water 1.1% ground water 3%
Irrigation surface water 0.6% ground water 2.1%
Other surface water 64.6% ground water 10.1%

Total daily withdrawls average 1,485 million gallons per day (5,620 million liters).
24% Ground water sources
76% Surface water sources

Lakes, ponds, and a few artificial reservoirs provide water and opportunities for recreation.

The surface water is abundant, but its quality may be degraded by the nonpoint sources of sediment, nutrients, and pesticides in runoff from agricultural land.

A number of unconsolidated and bedrock aquifers occur in the area. Most of the ground water used in the area is pumped from the surficial aquifer (buried channels, glacial drift, and alluvium) or the Ordovician and Cambrian sandstone and dolomite in the Jordan, or Prairie du Chien-Jordan, aquifer.

The water from both of the aquifers generally meets Federal and State drinking water standards. It is hard or very hard. The level of total dissolved solids in the water from the surficial aquifer is about 500 parts per million (milligrams per liter).

Soils

  • Mesic soil temperature regime.
  • Aquic or udic soil moisture regime.
  • Mixed mineralogy.
  • Dominant Soils:

  • Mollisols
  • Alfisols
  • Inceptisols
  • The soils are very deep and range from well drained to very poorly drained and loamy.

    Great Group Series Location
    Hapludolls Amiret, Clarion, Nicollet, and Ves series formed in loamy till on till plains and moraines
    Estherville and Hawick series formed in outwash deposits on outwash plains, terraces, and kames
    Argiudolls Le Sueur series formed in loamy till on till plains and moraines
    Argiaquolls Cordova series formed in loamy till on till plains and moraines
    Endoaquolls Canisteo, Glencoe, and Webster series formed in loamy till and/or local alluvium on till plains and in swales and depressions
    Calciaquolls Harps series formed in loamy till and/or local alluvium on till plains and in swales and depressions
    Endoaquolls Coland series formed in alluvium on flood plains
    Hapludalfs Hayden and Lester series formed in loamy till on moraines
    Eutrudepts Storden series formed in loamy till on moraines

    Fauna and Flora

    This area supports natural prairie vegetation characterized by little bluestem, Indiangrass, and switchgrass. Little bluestem, Indiangrass, and needlegrass grow on sandy, droughty soils. Little bluestem, sideoats grama, blue grama, and scattered bur oak, juniper, and sumac grow on very shallow soils.

    Some of the major wildlife species in this area include whitetailed deer, fox, beaver, muskrat, rabbit, squirrel, mink, Canada goose, pheasant, and gray partridge

    Land Use

    80% - Cropland - private
    5% - Grassland - private
    3% - Forest - private
    6% - Urban development - private
    2% - Water - private
    4% - Other - private

    Nearly all of this area is in farms. The proportion of cropland is highest in the southern part of the area. Corn, soybeans, and other feed grains are the major crops. Some of the cropland is used for hay. Dairy farming is a more common enterprise in the northern part of the area than in the southern part.

    Forested areas occur as narrow bands on steep slopes bordering stream valleys and as wet areas on bottom land.

    Many natural lakes occur in this area, and numerous bogs, swales, and circular depressions indicate sites of previously ponded water. Much of the area is currently drained by tile. Extensive drainage ditches provide outlets for the tile drains.

    The major resource concerns include water erosion, depletion of organic matter in the soils, excess surface and subsurface water, and poor water quality.

    Conservation practices generally include systems of crop residue management (especially no-till, strip-till, and mulch-till systems), cover crops, surface and subsurface drainage systems, nutrient and pest management, grassed waterways, buffer strips, and development of wildlife habitat.


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