Middle Provo River Temperature Study
The High Country Fly Fishers chapter of Trout Unlimited has begun a conservation program in conjunction with the Center for Advanced Professional Studies at Wasatch High School in Heber City, Utah, to monitor stream temperatures in the Middle Provo River between Jordanelle and Deer Creek reservoirs. The project, in which students collect macroinvertebrate samples and data from in-stream temperature dataloggers will run for 3 years and was initiated in response to concerns about the health of the fishery if the extreme drought conditions of 2021 and the rapid urbanization of the river basin continue. The project will monitor temperature changes along the river’s 12-mile length, tributary temperatures, diurnal temperature oscillations, and temperature differences between sunny and shaded river substrates. An added benefit of these measurements is to determine seasonal changes in temperature progression up the river as it affects insect hatches. The involvement of the high school students offers additional education benefits to future potential young scientists. Supervised data analyses will be conducted by the high school students as an educational project in which measured spatial and temporal temperature variations will be related to the rate and temperature of discharge from the Jordanelle dam, ambient atmospheric temperatures and solar radiation. Additionally, a publicly accessible web page is being developed to introduce fishermen to the Middle Provo, providing information on the fishery, the history of the dam and Middle Provo restoration projects, the angling access points, the hydrology and the macroinvertebrate numbers and diversity.
The temperature dataloggers were installed in late March and early April 2022. Initial results are shown above for the period 6-16 April 2022. Shown are temperature time series from sites running down the river from the Rickety Bridge 0.30 river miles below the Jordanelle dam to the Highway 113 bridge, which is 11.71 miles downriver and just upstream of Deer Creek Reservoir. Sites having names starting with the letter M are collocated with macro-invertebrate sampling sites serviced by students at Wasatch High School. Other sites are located near the River Road, Legacy, Trestle and Highway 113 bridges. Variable weather conditions cause variations in water temperature from day to day. Temperatures generally increase with distance downstream from the dam, with peak temperatures occurring in late afternoon. Nights with ambient air temperatures colder than the water being released at the dam cause water temperatures to decrease with distance downstream. Day-night water temperature differences at individual sites reach 9°C (16°F)! Cold water released from the dam takes some time during the late afternoon and evening to travel downstream. As data become available in other seasons, we expect to see other interesting features of the temperature distribution.