Problem: a low-lying, wet, unfarmable area on a farm.
Solution: a pond.
A reasonable solution, especially when your son-in-law has earth-moving equipment.
Back in the 1960s my Grandpa Cornelius Schumm (1896-1986) had a low area on his farm, located a little northeast of his barn.
His son-in-law Alvin Krueckeberg had the excavation equipment and turned that low area into a nice farm pond.
Here are couple photos of the Cornelius Schumm excavation. Although I do not have an exact year, I believe the Schumm farm was created in the early 1960s.
My Grandpa Schumm standing in his newly excavated pond.
Alvin Krueckeberg (1928-2019) excavated other ponds in the area. One of them was for Ned Alspaugh in 1974, across from Zion Lutheran Church at Schumm, which I wrote about a couple weeks ago.