Streams and rivers flowing out of the Boston Mountain ecoregion are primarily rainfall driven. This means that the rises in a hydrograph may be extreme and the period of flood brief. The majority of the base flow, a river level that is not rising or falling, of the Buffalo River is derived from spring inputs. This is dissimilar to other large rivers in the Springfield and Salem plateaus (see Ozark Scenic Riverways), because of the large spring systems that contribute to the flow. In these systems a rise in the hydrograph is more gradual, and the duration of the event is longer.
The Buffalo River is different from any other large system in the Ozarks because it's headwater region flows north out of the Boston Mountains and then turns east and flows along the boundary of the Boston Mountain and Springfield Plateau ecoregions, ending in the Salem Plateau. This is interesting because as the river approaches the zones having different geologic strata, the river becomes a losing stream, or begins to loose water to the underlying cave systems. During late summer within these losing reaches, the entire river can go underground leaving the river channel dry, but just as quick as the river enters these zones, it can reemerge from large karst fractures (springs in the river bed) which replenish the flow of the river. The U. S. Geological Survey has collected sixty-two years of flow records at a gauging station near St. Joe, Arkansas. These data shows that the Buffalo River has a record minimum daily flow of 7 cubic feet per second (cfs) in September 17, 1954 and a record maximum daily flow of 124,000 cfs in December 3, 1982. The maximum flow is comparable to the Mississippi River near Memphis, TN at base flow. This record illustrates the importance of rainfall to the floating condition of the Buffalo River. Be sure to check out the Buffalo River's Flood Warning System for river levels before planning a canoeing expedition.