region M Area 104 larger picture

Eastern Iowa and Minnesota Till Prairies

Almost all of the area is in the Dissected Till Plains Section of the province
Parts of the western edge are in the Western Lake Plain Section
The small part of the area in Wisconsin is in the Wisconsin Driftless Section.

Area includes portions of the following states:
74% in Iowa
22% in Minnesota
4% in Wisconsin

Total Land Area 9,660 square miles (about 25,040 square kilometers).

Towns/cities include:
Mason City, Cedar Falls, Waterloo, and Cedar Rapids, Iowa,
Austin, Minnesota.

There are some state parks in this MLUA.

Geology

Paleozoic bedrock sediments, primarily shale and limestone, underlie most of the area. Some limestone units containing fossils are exposed in road cuts in the northeast corner of the area and along the major rivers in the part of the area in Iowa. Bedrock units also are exposed on the Mississippi River bluffs near Red Wing, Minnesota.

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

The landscape is a nearly level to gently rolling glaciated plain with long slopes. The natural drainage network is well established and commonly described as dendritic, resulting in few lakes and ponds.

Topography -

Elevation ranges from 985 to 1,310 feet (300 to 400 meters). Local relief is 10 to 20 feet (3 to 6 meters).

Karst topography is common in this area.

Climate

The average annual precipitation in most of this area is 29 to 37 inches (735 to 940 millimeters).
Most of the rainfall occurs as high-intensity, convective thunderstorms during the summer.
The average annual temperature is 44 to 50 degrees F (7 to 10 degrees C).
The freeze-free period averages about 180 days and ranges from 160 to 195 days.

Major Hydrologic Unit Areas

Name Code Extent*
Upper Mississippi-Iowa-Skunk-Wapsipinicon (0708 ) 62%
Upper Mississippi-Maquoketa-Plum (0706) 19%
Upper Mississippi-Black-Root (0704 ) 17%
Chippewa (0705) 2%

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

Cannon, Zumbro, Root, and Cedar Rivers in Minnesota and the Beaver, Cedar, Winnebago, Shell Rock, and Wapsipinicon Rivers in Iowa.

Water

Estimated withdrawls in this MLRA:
Public supply surface water 6.5% ground water 27.6%
Livestock surface water 1.6% ground water 4.2%
Irrigation surface water 0% ground water 0.3%
Other surface water 36.3% ground water 23.4%

Total daily withdrawls average 365 million gallons per day (1,380 million liters).
56% Ground water sources
44% Surface water sources

Surface water is generally abundant in the many rivers in the area. It is of good quality and is suitable for all uses. It is used mainly for public supplies and industry.

A number of unconsolidated and bedrock aquifers are in the area. Most of the ground water used in this area is pumped from either 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.

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 aquifers generally meets Federal and State drinking water standards. The median level of 850 parts per million (milligrams per liter) total dissolved solids in the Jordan aquifer does exceed the secondary (esthetic) standard for drinking water in Iowa. The level of total dissolved solids is much lower in the Prairie du Chien-Jordan aquifer in Minnesota.

Water in both aquifers is hard or very hard, and 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
  • The soils are very deep and range from well drained to very poorly drained and loamy.

    Great Group Series Location
    Hapludolls Floyd, Kenyon, Marquis, Ostrander, and Readlyn series formed in loamy sediments over till on uplands.
    Hapludalfs Bassett, Kasson, and Racine series formed in loamy sediments over till on uplands.
    Argiudolls Dinsdaleseries formed in loess over till on uplands.
    Endoaquolls Maxfield and Tripoli series formed in loamy and silty sediments over till on uplands.

    Fauna and Flora

    This area supports prairie vegetation. Big bluestem and Indiangrass are dominant on the well drained soils in rolling areas. Switchgrass, prairie cordgrass, and prairie dropseed are better adapted to the somewhat poorly drained soils.

    Little bluestem, porcupinegrass, and sand lovegrass grow on sandy, rocky, dry sites. Forbs, such as clovers, phlox, sunflower, gayfeather, and goldenrod, grow on the more productive soils. Roundhead lespedeza, spiderwort, and flowering spurge grow on droughty soils.

    Loosestrife, bedstraw, milkweed, and tickclover are water-tolerant species that grow on wet soils.Switchgrass, sedges, and rushes grow on poorly drained soils in draws or valleys. Common cattails grow on swampy sites.

    Some of the major wildlife species in this area include whitetailed deer, beaver, otter, muskrat, squirrel, mink, pheasant, gray partridge, great blue heron, American egret, mallard, and teal.

    Land Use

    80% - Cropland - private
    5% - Grassland - private
    6% - Forest - private
    5% - Urban development - private
    1% - Water - private
    3% - Other - private

    Nearly all of this area is in farms, and about four-fifths is cropland. Much of the area is drained by tile. Extensive drainage ditches provide outlets for the tile drains.

    Corn, soybeans, other feed grains, and hay are the major crops. Raising and feeding hogs and beef cattle and dairying are important enterprises.

    The forestland in the area is mainly on wet bottom land and on steep slopes bordering stream valleys.

    The major resource concerns include water erosion, depletion of organic matter in the soils, excess surface and subsurface water, and poor water quality. Many of the wet soils require artificial drainage for good growth of the field crops commonly grown in the area.

    Conservation practices generally include systems of crop residue management (especially no-till, striptill, and mulch-till systems), cover crops, surface and subsurface drainage systems, nutrient and pest management, grassed waterways, terraces, manure management, pasture and hayland planting, and grade-stabilization structures.


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