The springs provide more than beautiful cascades of crystal clear water tumbling down a black lava canyon wall. These springs are the essential ingredient of the largest aquaculture complex in the United States, and are the source of water for irrigated agriculture and hydropower. The flows from these springs constitute the majority of annual flow in the Snake River below this reach and consequently are vital to the ecological health, recreational opportunities, and scenic attraction of the area.
The issuance of some many large discharge springs along a short length of river canyon is no coincidence. This area is the primary discharge area of one of the most productive aquifers in the world, the Snake River Plain aquifer. The Snake River Plain aquifer is contained in hundreds of feet of layered and fractured lava flows. The contact of each flow overlying an earlier flow creates the potential for formation of rubble, or broken up lava deposits. These rubble zones are thought to be highly conductive pathways for the flow of water. These pathways are probably not continuous over great distances, but create a scientific uncertainty in our understanding of ground water flow and the transport of potential ground water contaminants. The Snake River canyon in a sense forms a cross-section cut through the aquifer, and a possibly unequaled opportunity for scientific investigations of flow in highly fractured rock.
WHAT IS THE THOUSAND SPRINGS RESEARCH PROJECT?
The University of Idaho, with funding from the U.S. EPA is undertaking what is hopefully the first of a series projects investigating flow in the fractures of the Snake River Plain aquifer. The project is an initial step in answering some significant questions about flow in this, and similar, aquifers:
This research project will not answer all these questions, but it will provide some early insights and assist in the design of future projects to further investigate the questions and processes.
WHAT IS THE PROJECT DOING?
The Idaho Water Resources Research Institute at the University of Idaho is presently collecting existing information and measuring spring discharge and aquifer water level at selected locations in the Thousand Springs area. Depth to water is being measured in a network of 22 private wells along the Snake River canyon at a frequency of at least once a month. Spring discharge is being measured at nine springs either continuously or at the same frequency as well measurements. These measurements, along with data being collected by the U.S. Geological Survey and the Idaho Department of Water Resources are being used to evaluate seasonal changes in aquifer water level and the relationship of those changes to spring discharge.
A conceptual understanding spring and aquifer flow characteristics can also be enhanced water chemistry analysis. Variations in water quality potentially indicate different flow paths and possibly different flow systems. Earlier studies by the U.S. Geological Survey have demonstrated a wide variation in water chemistry and inferred relationships to flow paths. This project will build upon the understanding and data generated by earlier projects and attempt to further the understanding of flow systems.
Data collected by this project adds to the pool of information about the springs and furthers our understanding of the nature of the springs and factors that affect their flow and water quality.
Tracking harmless tracers through the aquifer provides the best means of evaluating the chemical transport characteristics of the aquifer. Potential tracers are being evaluated for compatibility with water uses in the area including domestic supply and aquaculture. Locations for potential tracer injection and recovery are also being researched. Hopefully, in future years, researchers from the University of Idaho and
other institutions will be emplacing tracers in the aquifer and analyzing the recovery of those tracers in springs that are hundreds of feet to possibly miles away.
WHERE CAN YOU LEARN MORE?
Aquifer water level and spring discharge data have been compiled for nearly a one-year period. The results of the first year's data collection are presently documented. When complete, the document will be available here on this website, above at the current reports link.
You may also directly contact:
Dr. Gary Johnson Dr. Donna Cosgrove
son, G.S. and D.M. Cosgrove., 1999, Application of Steady State Response Ratios to the Snake River Plain Aquifer: Idaho Water Resources Research Institute, University of Idaho, Moscow, ID, 31 p