David T. Poynter Paul W. Westerfield 1994 Water-level maps of the Mississippi River Valley alluvial aquifer are presented for spring 1992 in this map report. The alluvial aquifer consists of sand and gravel in flood-plain and terrace deposits of Quaternary age and supplies much of the water used for irrigation and aquaculture in eastern Arkansas. The map of the potentiometric surface, 5-year water-level change, and depth to water illustrates the effects of large with- drawals for irrigation on water levels in the aquifer. One large area of depression in the potentiometric surface, caused by large with- drawals of ground water for irrigation, occurs in Arkansas, Lonoke, and Prairie Counties, and another extends from Monroe County to western Craighead County. application/pdf 10.3133/ofr93374 en Water-level maps of the Mississippi River Valley alluvial aquifer in eastern Arkansas, spring 1992 reports