About 90 percent of the wetlands were drained for agricultural and urban development. The only sizable remnants are the shoreline wetlands of the Ottawa National Wildlife Refuge and Crane Creek State Park along Lake Erie and the freshwater delta marshes of the St. Clair Flats State Wildlife Area at the mouth of the St. Clair River. Because soils are fertile and the climate is temperate, the primary land use in this part of the study unit is agricultural, ranging from orchards and vineyards near the Lake Erie shoreline to cropland in corn and soybeans further inland. Here, successive glaciations have subdued the relief and buried many pre-glacial valleys. The topographic relief in this province is greater than that of the Central Lowland Province and consists of irregular plains dissected by stream valleys.
Land use is a mix of agriculture, forest, and urban areas.
Orchards and vineyards are located along the Lake Erie shoreline in this part of the study unit because of the moderating effect of the Lake on the local climate. From west to east, average annual temperature in the study unit is 48 to 51 degrees Fahrenheit, average annual precipitation is 31 to 40 in. However, recharge can be as high as 6 in. annually in some areas. Principal aquifers in the study unit consist of glacial or alluvial deposits and bedrock. The coarse-grained deposits in the northwestern corner of the study unit underlie glacial till or lake deposits, contain ground water that is locally confined under artesian pressure, and form aquifers that can be highly productive.