Two Rivers Help Draw Johnson County's Map

On a county map, the Brazos River draws much of the southwestern boundary. The smaller Nolan River runs north to south through Johnson County, passes through Lake Pat Cleburne, and joins the Brazos. Those two blue lines help make sense of the county's shape.

A river name alone does not tell you whether a particular house or building site is in a mapped flood hazard area. Search the exact address in FEMA's Map Service Center, open the panel, and check for later amendments. For unincorporated land, Johnson County Development Services is the local stop for floodplain permits and map questions.