Spring Monitoring and Measurement of Non-Point Source Recharge and Canal Seepage in Cache Valley, Utah
2005 Research Initiation Award Report
Investigators
Thomas E. Lachmar—Geology Dept., Utah State University
David Chandler—Plants, Soils, and Climate Dept., Utah State University
Wynn R. Walker—Biological and Irrigation Engineering Department, Utah
State University
Gary P. Merkley—Biological and Irrigation Engineering Department, Utah
State University
Summary
This investigation has been divided into two tasks. The first task was to
monitor springs, and the second task was to measure canal seepage. Over 100
springs were located and the discharges of 44 springs have been measured
monthly since May of 2005. Discharges for most springs have remained relatively
constant, and those that have varied do not appear to display any pattern in
their fluctuations. Samples were taken from 59 springs and analyzed for major
ions and metals. Major ion chemistry for most of the springs is similar to that
for surface streams and for wells completed into the deep confined (principal)
aquifer, and dissimilar to precipitation. Also, 34 samples were analyzed for
the stable isotope ratios of oxygen-18 to oxygen-16 (18O/16O) and deuterium
(2H) to hydrogen (D/H). One spring plotted near precipitation values and three
others plotted near stream water values, while the remainder display an
evaporative signature. All of these data suggest that most of the springs are
recharged by canal seepage and excess irrigation water, and that these are the
primary sources of recharge to the principal aquifer as well. The second task
was to conduct a detailed survey of the irrigation canals originating in the
Logan River. The survey included photographic records, GPS locations,
operations and maintenance practices and needs, and seepage measurements. New
GIS-based maps were prepared and distributed to interested irrigation company
officials. Inflow-outflow seepage measurements were made at multiple locations
in the following canals:
-
Logan Northfield Canal (1.82 cfs lost over 1,450 ft length, or 7.7% loss),
-
Southwest-Field Canal (0.41 cfs lost over 1,470 ft length, or 17% loss)
-
Smithfield Hyde Park Canal (5.1 cfs lost over 7,450 ft length, or 19% loss),
and
-
Benson Canal (1.6 cfs lost over 2,000 ft length, or 10% loss).
Results were incorporated into a comprehensive report available at:
http://www.engineering.usu.edu/bie/faculty/merkley/Downloads/Miscellaneous/Logan%20River%20Canals,%20Project%20Report.pdf
Contact Information
Thomas E. Lachmar
lachmar‹at›cc.usu.edu