Parts of Cache Valley are surrounded by mountains with geologic layers that have dissolved enough to create sinkholes, caves and springs among other porous geologic features. This is generally referred to as a karst landscape and creates natural aquifers that provide Logan and neighboring communities with much of their water.
While sources like these can be incredibly productive, it makes these communities heavily dependent on how much water seeps out of the ground and is then replenished primarily by snowmelt each spring.
Unfortunately, this porous landscape also makes it difficult to predict where and how much water makes it to the rivers in the mountains and how much connects to the groundwater in the valleys. Beth Neilson of the Department of Civil and Environmental Engineering and the Utah Water Research Laboratory works as a professor and director of the Logan River Observatory.
“Groundwater dynamics in mountainous karst watersheds, like the Logan, are very difficult to disentangle because groundwater flowpaths are highly unpredictable and do not follow watershed boundaries,” explained Neilson.
This karst geology makes for a particularly strong connection between groundwater and surface water in Logan Canyon. That connection and unpredictability can be a challenge when it comes to providing the community with necessary water, particularly in drier months and low snowpack years.
The Logan River Observatory has been monitoring the Logan River watershed since 2013, with the goal of using data to forecast how changes in the amount of precipitation will impact future water availability.
Through this monitoring they have been able to track the drastic shifts in flow throughout the watershed over the past several years, which is helping make decisions on where and when to move water throughout the valley.
“In very dry periods like 2021, many of our source water springs that are fed by high elevation snow pack dried up due to limited “deposits” or repeated years with limited precipitation,” said Neilson. "This year, after a record breaking winter, our springs are running high and the amount of flow in the river is nearly 2.5 times higher than that of last year.”
Since the river flow was so low in 2021, the valley depended more heavily on pumping groundwater, than it did in 2023.
“Understanding these connections provides insight into how changes to climate will impact water availability and how best to allocate and manage water.”
Stay tuned for more on the research and discoveries the water monitoring program is bringing to Cache Valley.
