An outwash city ringed by 1960s towns
Marion County is the oldest housing we work in, and the only place where the ground under the city is fundamentally different from the ground around it. The White River valley is outwash, fast draining, while the till plain a couple of miles out is dense and slow.
The suburbs around Indianapolis are almost all mid-century towns that finished growing. Southport, Speedway, Clermont and Beech Grove are 58 to 92 percent pre-1980. Lawrence is the exception, with a 1992 median build year. Permitting differs town by town: Speedway, Beech Grove, Lawrence and Southport run their own programs, while Clermont sits inside the city's and cannot adopt a lesser standard.
A lot on the White River terrace and a lot two miles east on the till plain perc-test nothing alike. In Marion County, what your neighborhood does with water is decided by which side of that line you are on.
Marion County, from the ground up