The River needs no other name, since it is the only river in the Enclave. It issues from the cliff face (sometimes called the Eastern Wall) at the eastern end of the Enclave, above Pine Slope, and falls about 150 meters to a small lake (Thunder Lake) below. From there it flows through Pine Slope and continues roughly through the middle of the Enclave, winding a little as it goes. At the western end of The Enclave, the River returns underground, passing through a heavy steel grate into a large opening in a low cliff. At that point, the river is wide (about 80 meters) and flows slowly. A few families living nearby are paid by the Enclave Council to monitor the grate, maintain it, and clear debris from it.
The River is spanned by several bridges along its length. It is about 40 meters across in most places. A few small creeks flow into it, including the outflow from the Hot Springs. Drinking water is piped from Thunder Lake to the rest of the Enclave by gravity; each neighborhood has a water supply point, and most major buildings (such as the Enclave Council Hall, the Mages' Guildhall, the Enclave Watchtower, and the Arena) have piped water inside. An intricate network of irrigation ditches collects water from upstream and distributes it by gravity to fields; small floodgates are under the control of the farmers to manage the water. Fishing is good in many locations.