Summary of the Snake River plain Regional Aquifer-System Analysis in Idaho and eastern Oregon

Abstract

The Regional Aquifer-System Analysis (RASA) Program was started in 1978 following a congressional mandate to develop quantitative appraisals of the major ground-water systems of the United States. The RASA Program represents a systematic effort to study a number of the Nation's most important aquifer systems, which in aggregate underlie much of the country and which represent an important component of the Nation's total water supply. In general, the boundaries of these studies are identified by the hydrologic extent of each system and accordingly transcend the political subdivisions to which investigations have often arbitrarily been limited in the past. The broad objective for each study is to assemble geologic, hydrologic, and geochemical information, to analyze and develop an understanding of the system, and to develop predictive capabilities that will contribute to the effective management of the system. The use of computer simulation is an important element of the RASA studies, both to develop an understanding of the natural, undisturbed hydrologic system and the changes brought about in it by human activities, and to provide a means of predicting the regional effects of future pumping or other stresses.The final interpretive results of the RASA Program are presented in a series of U.S. Geological Survey Professional Papers that describe the geology, hydrology, and geochemistry of each regional aquifer system. Each study within the RASA Program is assigned a single Professional Paper number, and where the volume of interpretive material warrants, separate topical chapters that consider the principal elements of the investigation may be published. The series of RASA interpretive reports begins with Professional Paper 1400 and thereafter will continue in numerical sequence as the interpretive products of subsequent studies become available..

Geochemical evolution of groundwater in the Mud Lake area, Eastern Idaho, USA

“…The ESRP aquifer is comprised of hundreds of intercalated, subhorizontal layers of basalt and sediment (Lindholm 1996) estimated to be [1,000 m thick in some locations (Garabedian 1992). A clay layer creates confined aquifer conditions in the area around Mud Lake (Spinazola 1994), but the aquifer is unconfined elsewhere.…”

Analysis of data on nutrients and organic compounds in ground water in the upper Snake River basin, Idaho and western Wyoming, 1980-91

“…Wells open to less than 100 ft of the aquifer yield as much as 7,000 gal/min; yields of 2,000 to 3,000 gal/min with only a few feet of drawdown are common (Whitehead, 1992;Lindholm, 1993), making yields from the eastern Snake River Plain aquifer some of the largest in the Nation. Transmissivity commonly exceeds 100,000 ft2/d and locally is as much as 1,000,000 ft2/d (Whitehead, 1992, p. B22).…”

“…6). Lindholm (1993) made the following estimates of recharge to the eastern Snake River Plain aquifer for 1980: (1) surface-water irrigation, 4.84 million acre-ft; (2) tributary drainage basin underflow, 1.44 million acre-ft; (3) precipitation on the plain, 0.70 million acre-ft; (4) Snake River losses, 0.69 million acre-ft; and (5) tributary and canal losses, 0.39 million acre-ft. Lindholm (1993) also made the following estimates of discharge from the eastern Snake River Plain aquifer for 1980: (1) spring flow, 7.08 million acre-ft; and (2) pumpage, 1.14 million acre-ft. About two-thirds of the water from spring flow discharges to the Snake River between Milner Dam and King Hill (Lindholm and others, 1988), and the other third discharges between Blackfoot and Neeley (Mundorff and others, 1964). Lindholm (1993) estimated that ground-water discharge exceeded recharge by 0.1 to 0.16 million acre-ft in 1980.…”

Groundwater-quality data from the eastern Snake River Plain Aquifer, Jerome and Gooding Counties, south-central Idaho, 2017

“…Layered basalt flows in the ESRP aquifer yield exceptionally large volumes of water to wells and springs. Individual well yields in the ESRP are some of the highest in the nation, typically ranging from 2,000 to 3,000 gal/min to as much as 7,000 gal/min with minimal drawdown (Whitehead, 1992;Lindholm, 1996). Transmissivity is commonly 100,000 ft 2 /d, and can be as high as 1,000,000 ft 2 /d (Whitehead, 1992).…”