The Trench River is one of the largest rivers in Surdam. The river is a dry river, meaning it won't flow unless after a rainstorm or a lot of snow melt. The river is separated into two halves by the Elizabeth Dam, the Upper Trench River flows mostly in the summer after rainstorms. The Lower Trench River also flows after rainstorms with the upper half flowing into it, it also flows during the winter if the temperature rises enough where snow will melt causing the lower half to flow. Along the upper half is a small stream called Little Rapids Stream, which flows after rain and snowmelt.