One hundred and seventy-seven drillers' well reports were used to investigate the groundwater resources of Baxter, Fulton, Izard, and Sharp counties. The most widely utilized aquifer zone is composed of the Cotter and Jefferson City dolomites. The well depths range from 30 to 740 ft. with a mean and median of 264 and 225 ft., respectively. The drillers' yield estimates range from 1 to 50 gpm with a mean of 12.0 gpm and a median of 10 gpm. The piezometric surface has an average hydraulic gradient of 9 ft./mile with groundwater discharge occurring along the Spring and White Rivers. Overlying the Cotter-Jefferson City aquifer is the Powell Dolomite aquifer. Well depths range from 43 to 275 ft. with a mean and median of 137 and 114 ft., respectively. Driller estimated yields range from 7 to 40 gpm with a mean and median of 18 and 15 gpm, respectively. The Everton Aquifer is composed of a complex series of interfingering sandstones and carbonate layers that may act collectively or Individually as aquifers. Well depths in this aquifer range from 8 to 812 ft. with a mean of 338 ft. and a median of 500 ft. Yields range from 1 to 40 gpm with a mean and median of 11 and 7 gpm, respectively. The least productive and least utilized, but shallowest aquifer is the St. Peter Sandstone aquifer which has a depth range of 55 to 113 ft. with a mean and median of 80 and 85 ft., respectively. The yield ranges from 1 to 20 gpm with a mean and median of 9 and 5 gpm, respectively. The Spearman Rank Correlation procedure was used to compare well yields (gpm), well depth, regolith thickness, depth to water, and piezometric surface elevation of the Cotter-Jefferson City aquifer. At ∝ = 0.1, the following relationships were established: 1) greater yield at shallow well depths, 2) greater yield where the water table is closer to the surface, 3) thicker regolith in deeper wells, and thicker regolith with increased depth to water. These correlations indicate the strong control on water movement by fractures in the aquifer, and "closing off" of fractures at depth, and the control of regolith thickness by depth to water rather than fracture proximity.
Liebelt, Mike; Lundy, Gerald; and Ogden, Albert E.
"Preliminary Investigation of the Ground-Water Resources of Baxter, Fulton, Izard and Sharp Counties, Arkansas,"
Journal of the Arkansas Academy of Science: Vol. 34, Article 22.
Available at: https://scholarworks.uark.edu/jaas/vol34/iss1/22