Geology topics

Research about Umatilla Indian Reservation

Source-linked reports with geographic coverage including Umatilla Indian Reservation.

4 recordsLinked to original sources

USGS2024

Water-level change from a multiple-well aquifer test in volcanic rocks, Umatilla Indian Reservation near Mission, northeastern Oregon, 2016

The U.S. Geological Survey, in cooperation with the Confederated Tribes of the Umatilla Indian Reservation (CTUIR), (1) estimated water-level change from a multiple-well aquifer test centered on CTUIR well number 422 and (2) evaluated hydraulic connections between the pumping and observation wells on the Umatilla Indian Reservation near Mission, northeastern Oregon to improve the understanding of aquifer characteristics and hydrologic flow boundaries. Water-level changes, or pumping responses, were determined by distinguishing the pumping signal from environmental fluctuations in groundwater levels using analytical water-level models. The pumping well produces water from basalt units from a depth of 450 to 1,057 feet below land surface and was intermittently pumped during February 1–April 18, 2016. Water-level responses to pumping were estimated in the pumping well and in seven observation wells within 4 miles (mi) of the pumping well. The observation wells are open to basalt and some observation wells are either separated from the pumping well by faults and other structural features, within structural zones, or adjacent to structural features. Pumping responses at the observation wells were classified as detected in two wells, ambiguous in one well, and not detected in four wells. Observation-well open-interval elevations overlapped with the pumping-well open interval in both wells with detected pumping responses. Observation wells with detections are 1.8 mi east of the pumping well and across a fault, and 1.4 mi south of the pumping well. The pumping response was classified as ambiguous in an observation well located 1.4 mi west of the pumping well, where the dip of the basalt unit steepens, and adjacent to the Agency syncline. Pumping responses were not detected in observation wells within 0.3 mi of the pumping well where observation-well open-interval elevations are above the top of the pumping well open interval. Analysis of pumping responses indicates (1) a more permeable zone of basalt is adjacent to the lower portion of the pumping-well open interval and extends eastward, (2) basalt adjacent to the upper portion of the pumping-well open-interval is less permeable than the lower portion or separated from the lower portion by a less permeable zone, and (or) (3) a less permeable zone limits vertical hydraulic connectivity between the pumping well and the overlying basalt.

Oregon↗

USGS2018

Geothermal potential of the Umatilla Indian Reservation, Oregon: Evidence from detailed geophysical investigations

Recent geologic and geophysical investigations were undertaken in northeastern Oregon to better assess earthquake hazards in the region and determine relative favorability for geothermal energy development on lands of the Confederated Tribes of the Umatilla Indian Reservation (CTUIR). This work was funded in part by a Bureau of Indian Affairs grant awarded to the CTUIR to identify areas most suitable for further exploration of geothermal resources. Results from this work were utilized as inputs to a geothermal favorability modeling process that led to the identification of target sites for further geothermal investigation. Beyond the geothermal aspect of this project, the region is of great tectonic significance as it marks the intersection of two major physiographic and geophysical features, the Klamath-Blue Mountain lineament (KBL) and Olympic-Wallowa lineament (OWL), inferred to represent major basement boundaries. The Thorn Hollow and Hite faults, which appear to be major linkages between the KBL and OWL, run through the study area. New aeromagnetic, gravity and magnetotelluric (MT) surveying, along with fault analyses, were conducted as part of this effort. Detailed geophysical exploration resulted in the collection of 1,380 new gravity stations, 34,524-line kilometers of aeromagnetic data (covering 12,524 km2) and measurements from 36 MT stations. Two-dimensional (2D) forward-modeling was executed along several profiles using gravity and aeromagnetic data, combined with existing geologic mapping and rock property constraints measured from hand samples and outcrops. These models are used to define lithologic contacts in the subsurface in the absence of well logs or borehole data to determine possible geothermal fluid reservoirs, as well as identify major structures that may act as conduits for the upward migration of geothermal fluids.

Oregon↗

USGS2015

Physical habitat monitoring strategy (PHAMS) for reach-scale restoration effectiveness monitoring

Habitat restoration efforts by the Confederated Tribes of the Umatilla Indian Reservation (CTUIR) have shifted from the site scale (1-10 meters) to the reach scale (100-1,000 meters). This shift was in response to the growing scientific emphasis on process-based restoration and to support from the 2007 Accords Agreement with the Bonneville Power Administration. With the increased size of restoration projects, the CTUIR and other agencies are in need of applicable monitoring methods for assessing large-scale changes in river and floodplain habitats following restoration. The goal of the Physical Habitat Monitoring Strategy is to outline methods that are useful for capturing reach-scale changes in surface and groundwater hydrology, geomorphology, hydrologic connectivity, and riparian vegetation at restoration projects. The Physical Habitat Monitoring Strategy aims to avoid duplication with existing regional effectiveness monitoring protocols by identifying complimentary reach-scale metrics and methods that may improve the ability of CTUIR and others to detect instream and riparian changes at large restoration projects.

Idaho, Oregon, Washington↗

USGS1977

Water resources of the Umatilla Indian Reservation, Oregon

Water resources of the Umatilla Indian Reservation are poorly distributed both geographically and in time. On the reservation, only the Umatilla River and one of its principal tributaries, Meacham Creek, have significant perennial flows. Runoff of the principal streams is largely from snowmelt in the Blue Mountains and is highly variable. The principal aquifers are the Columbia River Basalt Group and the Quaternary alluvium. The basalt underlies the entire reservation to a depth of a few thousand feet, and most wells tap this source. The Quaternary alluvium is present only in the valleys of the principal streams. The alluvium averages about 12 feet (ft) in thickness in the Umatilla River valley, where it has the greatest extent; elsewhere it is generally thinner. Surface-water outflow from the reservation averages about 600 cubic feet per second (ft 3 /s), and the total stream inflow is about 540 ft 3 /s. About 480 ft 3 /s of the outflow is in the Umatilla River, 106 ft 3 /s is in McKay Creek, and 14 ft 3 /s is in other streams. Dependable streamflow, defined here as the 7-day mean low flow that will occur once every 50 years, on the average, is 30 ft 3 /s in Umatilla River above Meacham Creek near Gibbon, 5 ft 3 /s in Meacham Creek below Line Creek at the east boundary, 33 ft 3 /s in Umatilla River at Cayuse, and 14 ft 3 /s in Umatilla River at Pendleton. Monthly mean flows in Umatilla River above Meacham Creek near Gibbon in summer and fall frequently are less than the published recommended minimum flows for spawning and rearing of trout; in the reach of the Umatilla River near Pendleton the summer and fall flows generally are below those recommended minimum flows. Wells in the Columbia River Basalt Group range in depth from a few to 1,910 ft, and their yields range from less than 1 to more than 1,200 gallons per minute (gal/min). Small yields adequate for domestic needs can generally be obtained from the basalt. The depths required for successful wells may be extremely variable. Evaluation of specific-capacity data from wells in the basalt in four geographic areas suggests that the basalt is more permeable beneath the south reservation and the Umatilla River valley, that the permeability decreases on the north reservation, and that it is least in the Blue Mountains. Surface and ground waters generally are of good quality and suitable for most uses. Surface water is soft and generally contains less than 120 milligrams per liter (ug/L) of dissolved solids. Dissolved oxygen in streams is generally at or close to saturation levels at most stream temperatures and discharge rates. Ground water ranges from soft to very hard (28 to 280 mg/L), but it generally ranges between moderately hard to hard (61 to 180 mg/L). Dissolved solids in ground water range from 88 to 561 mg/L, but generally are between 200 and about 250 mg/L. During 1975, an estimated 11 million gallons per day (Mgal/d) of surface and ground water was withdrawn from the reservation for all uses. About 4 Mgal/d was from surface-water sources and 60 percent, or 7 Mgal/d, was from ground-water sources. About 7.2 Mgal/d was used for irrigation, 3.6 Mgal/d for public supply, and the remainder was for domestic and industrial use. About 4 Mgal/d, or 40 percent of the total water withdrawn, was for public supply and for irrigation use outside the reservation boundaries. Local seasonal declines of ground-water levels of 100 ft or more occur in shallow basalt wells in the Umatilla River valley between Mission and the west boundary. The declines are due chiefly to pumping from many small-capacity shallow wells in the basalt for irrigation of lawns and small acreages of pasture or hay. Future potential problems on the reservation include regional decline of ground-water levels in the basalt aquifer and local contamination of surface and ground water from accidental spills of deleterious substances.

Oregon↗