By Abe Springer
Importance of Springs to Humans
Humans have relied on springs for millennia. Since the beginning of human evolution, populations spanning all seven continents have built entire communities around these sources of water, because they are dependable, plentiful and not as subject to the changes of climate and stream flow.
According to the Springs Stewardship Institute, springs support more than 10 percent of the endangered species in the United States, making them some of the most biologically and culturally important ecosystems on Earth. They function as hotspots for biodiversity and often support many rare and endangered plant and animal species.
Yet, despite their intrinsic benefits to the ecosystem, they continue to be understudied and inadequately protected, especially with increasing diversion of groundwater flow from the sources of springs by pumping the aquifers which supply them.
Over the past 15 years, I have studied more than 1,000 springs, closely examining the relationship between springs and the health of the aquifer. I have discovered that springs are of inestimable value to plants and wildlife in landscapes where they occur and have also learned that springs continue to be as important to populations today as they were thousands of years ago.
We have also found that in many ways, springs are the canary in the coal mine for groundwater sources.
Springs as an Indicator of Groundwater Health
I recently published a study in the journal Ecohydrology along with colleagues at the Springs Stewardship Institute of the Museum of Northern Arizona and the University of Lethbridge in Alberta, Canada. Our research found 25 percent of Alberta’s plant species in only 56 springs, which occupies less than four hectares (10 acres) of spring habitat. There are similar high densities of life at spring ecosystems in other landscapes we have studied in detail, such as the Spring Mountains of Nevada and the Grand Canyon of Arizona.
Springs function as keystone ecosystems, providing significantly greater ecological services to landscapes than their small size might imply because of the permanence of water. But, they are extraordinary, sensitive indicators of human impacts to aquifers and can often preemptively determine the health of groundwater sources.
Declines in the quantity of flow discharging from springs or the levels of groundwater in the aquifer adjacent to springs reflect either a decrease in recharge to the aquifer or capture of flow in the aquifer through pumping. Because aquifers are remote and usually hidden beneath the Earth, the surface expression of the spring is a convenient and easy observation location for the health of the aquifer.
The first and one of the most famous examples of legally mandated changes in aquifer management was due to species-related impacts to a remote, isolated, desert fish in Nevada. Pumping-related threats to the water level in Devils Hole, a spring in a detached unit of Death Valley National Park and home of the endangered Devils Hole Pupfish, led to a landmark Supreme Court decision in 1976 to regulate pumping because of ecosystem impacts. Since the decision, a recovery program has been established which includes a new National Wildlife Refuge for the Ash Meadows area surrounding Devils Hole.
Being Better Spring Stewards
Despite this ecological importance of springs on landscapes, the high demand for bottled water from springs, climate change and land management change imperils many spring ecosystems. Groundwater pumping diverts water from aquifers that would naturally discharge to springs, causing some springs to seasonally or permanently dry. Because many springs-dependent species rely on permanent, continuous discharge of groundwater from aquifers, even one drying event can lead to the loss of many ecosystem services and values.
As we proactively and reactively manage drought in the United States and across the world, it is imperative that we protect our springs. Like any environmental call to action in which we hope to drive change, the first step is to arm researchers with knowledge. It’s why, in partnership with Dr. Larry Stevens and Jeri Ledbetter of the Springs Stewardship Institute, we are creating a robust database of thousands of springs in the United States, available to springs researchers and managers around the world.
The second step is to establish water management tools and best practices. The Springs Stewardship Institute is also working to develop and translate through their website and through workshops internationally consistent inventory, assessment, monitoring, and restoration techniques for springs ecosystems. The increased availability of these new scientific methods will provide land and resource managers with better tools to be more effective stewards on the importance of springs.
With improved and consistent tools, techniques and data, humans can be better stewards of the aquifers which supply springs, and ultimately contribute to the livelihood of some of the most diverse and important ecosystems on Earth.
Dr. Abe Springer is a professor of hydrogeology and ecohydrology at the School of Earth Sciences and Environmental Sustainability at Northern Arizona University. For the past 20 years, he has studied local and regional groundwater flow systems and the human impacts on them.