A college town on wet loam and glacial sand, with the Chippewa running through it.
Mount Pleasant is the Isabella County seat and home to Central Michigan University, and its housing shows it. Census estimates count about 8,550 homes in the city, and close to 64 percent of the occupied ones are rented. The median home dates to 1976, yet about 17 percent were built in 1939 or earlier, and the downtown historic district around Broadway and Main holds 70 buildings from the 1870s to the 1950s. Past the city line, in the 48858 ZIP area, the median home was built in 1986 and about half are owner occupied.
The ground here comes in two kinds. In NRCS soil maps of the Mount Pleasant area, Conover loam is the most common single soil: clay loam till with a perched water table 6 to 18 inches down from September to May. Londo loam behaves much the same. Other built-up parts of town sit on sandy Mecosta and Thetford soils, and Cohoctah soils on the river flats hold water near the surface. On wet loam a slab needs a base that drains, and on sand it needs one packed tight. We excavate, compact the subbase and lay gravel bedding either way.
Winter is hard on flatwork here. The NOAA station at Central Michigan University averages 22.7 degrees in January, and in a normal year about 89 days freeze overnight and climb above 32 by afternoon. City crews run five salting routes each winter, and salt is rough on concrete close to the street. Then there is the Chippewa. Below Mount Pleasant it crested at 15.58 feet in September 1986 and 14.77 feet on June 23, 2017, when more than 100 roads in and around the city closed and a state of emergency was declared for Isabella County.
Inside city limits, the Building Safety department runs building permits. Sidewalks, driveway aprons and curb cuts in the right-of-way each need a permit from the Division of Public Works before work starts. City code makes owners keep the walk along their lot safe, gives 30 days to fix one the city flags, and wants snow off it within 24 hours. A new approach onto Mission Street, which carries Business US 127, needs an MDOT driveway permit too. Out in the county, the Isabella County Road Commission permits driveways on county roads, and each spring it cuts legal truck loads by 35 percent while the frost leaves the roadbed.
What Mount Pleasant concrete runs into
- Lifted slab edges on Conover loam, where water sits 6 to 18 inches down from September to May.
- Basement seepage on the north side, where many homes sit in high water at a 10-foot Chippewa stage.
- Sunken walks and steps at the 17 percent of city homes built in 1939 or earlier.
- Scaled walks and aprons on streets along the city's five winter salting routes.
- Sinking pads on sandy Mecosta and Thetford ground where the base was never compacted.
- Ponding drives after cloudbursts like August 11, 2010, when 4.16 inches fell in two and a half hours.
