John P Hoffmann (Former Employee)
Science and Products
Heat as a tool for studying the movement of ground water near streams Heat as a tool for studying the movement of ground water near streams
Stream temperature has long been recognized as an important water quality parameter. Temperature plays a key role in the health of a stream’s aquatic life, both in the water column and in the benthic habitat of streambed sediments. Many fish are sensitive to temperature. For example, anadromous salmon require specific temperature ranges to successfully develop, migrate, and spawn [see...
Characteristics of shallow deposits beneath Rillito Creek, Pima County, Arizona Characteristics of shallow deposits beneath Rillito Creek, Pima County, Arizona
Characteristics of the stream-channel and basin-fill deposits beneath a 12-mile reach of Rillito Creek, Pima County, Arizona, were obtained to describe the geohydrologic system. The findings presented here are part of a larger project to improve the understanding of recharge processes beneath ephemeral streams. The stream-channel deposits, which range in thickness from 15 to 40 feet...
Authors
John P. Hoffmann, Marcella A. Ripich, Kevin M. Ellett
Quality of water and estimates of water inflow, northern boundary area, Fort McDowell Indian Reservation, Maricopa County, Arizona Quality of water and estimates of water inflow, northern boundary area, Fort McDowell Indian Reservation, Maricopa County, Arizona
Increased agricultural and recreational activities and recent growth of population centers within the Verde River basin have led to concerns about the quality and quantity of water flowing onto the Fort McDowell Indian Reservation. The purpose of this study was to determine the quality and quantity of water in the Verde River and in the shallow stream-channel deposits in the vicinity of...
Authors
John P. Hoffmann, Christie M. O’Day
Hydrogeology, water quality, and stormwater-sediment chemistry of the Grande Wash area, Fort McDowell Indian Reservation, Maricopa County, Arizona Hydrogeology, water quality, and stormwater-sediment chemistry of the Grande Wash area, Fort McDowell Indian Reservation, Maricopa County, Arizona
Grande Wash is a tributary of the Verde River and drains an area of 13 square miles within the McDowell Mountains and the Town of Fountain Hills in Central Arizona. The wash enters the Fort McDowell Indian Reservation at the eastern boundary of Fountain Hills and is incised in coarse-grained alluvium that is contiguous with the alluvial aquifer along the Verde River. The aquifer is used...
Authors
John P. Hoffmann
Geology, Ground-Water Occurrence, and Estimated Well Yields from the Mariana Limestone, Kagman Area, Saipan, Commonwealth of the Northern Mariana Islands Geology, Ground-Water Occurrence, and Estimated Well Yields from the Mariana Limestone, Kagman Area, Saipan, Commonwealth of the Northern Mariana Islands
A study of the geology, ground-water occurrence, and estimated well yields from the Mariana Limestone was done to investigate ground-water availability in the Kagman area, Saipan. The Mariana and Tagpochau Limestone formations form the major aquifer in the Kagman drainage basin. The Mariana Limestone, which is the major water-bearing unit in the Kagman area, ranges in thickness from 300...
Authors
John P. Hoffmann, Rob Carruth, William Meyer
Geochemical analyses of ground-water ages, recharge rates, and hydraulic conductivity of the N aquifer, Black Mesa area, Arizona Geochemical analyses of ground-water ages, recharge rates, and hydraulic conductivity of the N aquifer, Black Mesa area, Arizona
The Navajo Nation and Hopi Tribe of the Black Mesa area, Arizona, depend on ground water from the N aquifer to meet most tribal and industrial needs. Increasing use of this aquifer is creating concerns about possible adverse effects of increased ground-water withdrawals on the water resources of the region. A thorough understanding of the N aquifer is necessary to assess the aquifer's...
Authors
Thomas J. Lopes, John P. Hoffmann
Science and Products
Heat as a tool for studying the movement of ground water near streams Heat as a tool for studying the movement of ground water near streams
Stream temperature has long been recognized as an important water quality parameter. Temperature plays a key role in the health of a stream’s aquatic life, both in the water column and in the benthic habitat of streambed sediments. Many fish are sensitive to temperature. For example, anadromous salmon require specific temperature ranges to successfully develop, migrate, and spawn [see...
Characteristics of shallow deposits beneath Rillito Creek, Pima County, Arizona Characteristics of shallow deposits beneath Rillito Creek, Pima County, Arizona
Characteristics of the stream-channel and basin-fill deposits beneath a 12-mile reach of Rillito Creek, Pima County, Arizona, were obtained to describe the geohydrologic system. The findings presented here are part of a larger project to improve the understanding of recharge processes beneath ephemeral streams. The stream-channel deposits, which range in thickness from 15 to 40 feet...
Authors
John P. Hoffmann, Marcella A. Ripich, Kevin M. Ellett
Quality of water and estimates of water inflow, northern boundary area, Fort McDowell Indian Reservation, Maricopa County, Arizona Quality of water and estimates of water inflow, northern boundary area, Fort McDowell Indian Reservation, Maricopa County, Arizona
Increased agricultural and recreational activities and recent growth of population centers within the Verde River basin have led to concerns about the quality and quantity of water flowing onto the Fort McDowell Indian Reservation. The purpose of this study was to determine the quality and quantity of water in the Verde River and in the shallow stream-channel deposits in the vicinity of...
Authors
John P. Hoffmann, Christie M. O’Day
Hydrogeology, water quality, and stormwater-sediment chemistry of the Grande Wash area, Fort McDowell Indian Reservation, Maricopa County, Arizona Hydrogeology, water quality, and stormwater-sediment chemistry of the Grande Wash area, Fort McDowell Indian Reservation, Maricopa County, Arizona
Grande Wash is a tributary of the Verde River and drains an area of 13 square miles within the McDowell Mountains and the Town of Fountain Hills in Central Arizona. The wash enters the Fort McDowell Indian Reservation at the eastern boundary of Fountain Hills and is incised in coarse-grained alluvium that is contiguous with the alluvial aquifer along the Verde River. The aquifer is used...
Authors
John P. Hoffmann
Geology, Ground-Water Occurrence, and Estimated Well Yields from the Mariana Limestone, Kagman Area, Saipan, Commonwealth of the Northern Mariana Islands Geology, Ground-Water Occurrence, and Estimated Well Yields from the Mariana Limestone, Kagman Area, Saipan, Commonwealth of the Northern Mariana Islands
A study of the geology, ground-water occurrence, and estimated well yields from the Mariana Limestone was done to investigate ground-water availability in the Kagman area, Saipan. The Mariana and Tagpochau Limestone formations form the major aquifer in the Kagman drainage basin. The Mariana Limestone, which is the major water-bearing unit in the Kagman area, ranges in thickness from 300...
Authors
John P. Hoffmann, Rob Carruth, William Meyer
Geochemical analyses of ground-water ages, recharge rates, and hydraulic conductivity of the N aquifer, Black Mesa area, Arizona Geochemical analyses of ground-water ages, recharge rates, and hydraulic conductivity of the N aquifer, Black Mesa area, Arizona
The Navajo Nation and Hopi Tribe of the Black Mesa area, Arizona, depend on ground water from the N aquifer to meet most tribal and industrial needs. Increasing use of this aquifer is creating concerns about possible adverse effects of increased ground-water withdrawals on the water resources of the region. A thorough understanding of the N aquifer is necessary to assess the aquifer's...
Authors
Thomas J. Lopes, John P. Hoffmann