“Is it a weird year for that?â€
By Ollie Cox, ACE EPIC BLM Member
When I meet someone for the first time here in Moab, our initial conversation tends to follow a similar pattern. If I mention that I’m a hydrology technician, people tend to ask if this is a weird year to be studying water. It’s a fair question. The US Southwest is in a multi-decade megadrought, and this year has been particularly dry. This year’s snowpack was the lowest on record in Utah, which directly translates into less snowmelt and lower flows in streams and rivers. With this in mind, I wasn’t sure exactly what to expect when this field season began. In part, I wasn’t sure how drought conditions would affect my work, but also the focus of my work would be a little different from what I was used to. Before this ACE internship, most of my hydrology experience was related to streams. In my home state of Washington, I had surveyed streams to assess conditions for fish habitat, and during an ACE internship last summer, I surveyed streams on public grazing land with the BLM Winnemucca District Office in Nevada. But this summer I wouldn’t be putting on any waders. Instead, I would be hiking in a mostly desert landscape and looking for springs in BLM’s Canyon County District.
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In terms of hydrology, springs are a bit like the neglected middle child. Compared to rivers and lakes, springs have received much less major study or documentation. But while these sites occupy a smaller area, they tend to be biodiversity hotspots. Springs act as an important source of water for plants and animals and support a high number of rare and endangered species. That’s why these sites are worth paying attention to, and their documentation is vital to land-use and water management decisions.
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It’s felt like a privilege to get to see and explore some of these sites, and there are a number of things I’ve been surprised to learn. While I knew generally that a spring is a location where groundwater emerges at the surface, I was mostly unfamiliar with the different types of springs. One type of spring that is somewhat unique to the Colorado Plateau, including southeast Utah, is called a hanging garden.
These are springs where water emerges from a horizontal contact along a rock wall, and you’ll often see them emerging from layers of sandstone. When these springs are vegetated, they can create a stunning garden suspended along a rock wall. These springs host a unique plant community—you’ll often see alcove columbine (Aquilegia micrantha), Eastwood’s monkeyflower (Mimulus eastwoodiae), stream orchids (Epipactis gigantea), black maidenhair fern (Adiantum capillus-veneris), and if you’re lucky, you might see rare, endemic species such as alcove death camas (Anticlea vaginata), cave dwelling primrose (Primula specuicola), or threatened Navajo sedge (Carex specuicola).
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I was also fascinated to learn about the timescales in which water moves through spring systems. Scientists can age-date the water from a spring to discover when that water was last exposed to the atmosphere and therefore how long it’s spent underground. Depending on the system, the water from a spring could have spent up to hundreds or even hundreds of thousands of years underground before emerging at the surface. I always feel a little awe-struck by that fact. Take a moment to pause and think about the hanging garden from earlier. Can you imagine rain hitting the ground and then spending thousands of years slowly infiltrating through layers of sandstone? The water will slowly flow through the porous rock before eventually hitting some less permeable layer, causing the water to change direction and move laterally until it emerges from the face of the rock.
Upon learning about the long time scale involved for water to move through a spring system, I found myself wondering why conditions today affect spring flow. If, for example, the water in a spring took ten thousand years to reach the surface, then shouldn’t there be a ten thousand year lag before current drought conditions affect that spring’s flow? Well, not quite. My supervisor explained the reason using a helpful analogy. Imagine a spring as a bucket with a hole near the bottom. The rate at which water flows out the hole is affected by how full the bucket is. The more water in the bucket, the greater the pressure (what hydrologists refer to as hydrostatic pressure). Spring flow varies seasonally based on a number of factors, increasing as water is replenished by precipitation or melting snowpack. Overall, in years of drought, there is less water to replenish the system, meaning less hydrostatic pressure and less spring flow.
Already we’re seeing the effects of current drought conditions on springs, and more springs are expected to shrink or dry up entirely as a result of climate change. Unfortunately, spring systems face a number of other threats as well. Springs are affected by water management decisions related to diversions and groundwater pumping and land use practices such as development, mining, livestock grazing, and recreation. Another important use for the spring inventory data I collect is that it can be used by the BLM to apply for water rights, which can help protect sites from threats, like private development. By holding a water right on a spring, the BLM can help ensure that the water stays in place and available to plants, wildlife, and the public.
To answer the question from earlier: yes, perhaps it is a weird year to be studying springs, but I’m glad that I get to. I love visiting these tucked-away spots, and I think it’s important to be documenting their conditions. I hope these sites will still be there in the future, and I think if we play our cards right, they will be.
