Posted on February 20, 2025
MANSFIELD — How deep is the Clear Fork Reservoir, the 4.4 billion gallon body of water that supplies most of the drinking water for the City of Mansfield?
The best answer is: It depends on where you measure.
Thanks to a bathymetric survey planned this year by Stantec Consulting Services, the city will have a good idea of exactly what’s under the water at the reservoir, which was completed four years after the end of World War II (1949).
City engineer Bob Bianchi said the funding was previously approved by City Council and is in the 2025 water fund budget.
“We want to determine how much sedimentation has occurred over the life of the reservoir for the past 75 years … looking at the sedimentation rates we know what we can expect going forward,” he said.
A bathymetric survey, sometimes referred to as a fathometric survey, is a type of hydrographic (water-based) survey that maps the depths and shapes of underwater terrain to illustrate the land that lies below.
The reservoir supplies about 60 percent of the city’s drinking water on an average day with the remainder coming from city-owned wells.
