Despite Roundhead's proximity to Indian Lake and the Great Miami River, which flows out of it to the Ohio River at Cincinnati, the community is drained by the headwaters of the Scioto River, which meets the Ohio River at Portsmouth.
Situated near Indian Lake and the Great Miami River, which flows into the Ohio River in Cincinnati, Roundhead's location is actually served by the tributaries of the Scioto River, which merge with the Ohio River at Portsmouth.