In a cool side canyon the sound of dripping waters mixes with the cascading notes of canyon wren. Columbine nod and bob in the slight down-canyon breeze. Tiny rivulets run between delicate shooting stars, maidenhead fern, and scarlet monkeyflower then gather and continue, joining the roiling Colorado River where a California condor stoops to drink.
Springs are one of the critical natural resources to Grand Canyon National Park. Spring discharge is seen as a singular response to the hydrologic character of a much larger area and an indication of the status of the supplying aquifer systems. This water provides base flow to the Colorado River, and provides drinking water to wildlife and Park visitors in an otherwise arid environment. Springs also support valuable riparian habitats, where species diversity is 100 to 500 times greater than the surrounding areas. Grand Canyon springs are often locations of exceptional natural beauty and many hold cultural significance to Native Americans in the region. Finally, these waters aid in the erosive process that formed the canyon itself.
Grand Canyon National Park, with the assistance of outside partners such as the U.S. Geological Survey and the Grand Canyon Wildlands Council, conducts research on the effects of development, groundwater withdrawal, and climate change on springs and seeps throughout the Park: Grand Canyon’s native waters.
Water resource management has been pushed into the spotlight in response to the rapid population growth in the western U.S. over the past decade, and this holds true for the area surrounding Grand Canyon National Park. Developments to the south of the Park, such as the community of Tusayan, put increased pressure on the existing groundwater resources of the Coconino Plateau, which is the recharge area of the regional aquifer system and South Rim springs. Previously, groundwater was obtained via wells from shallow aquifer systems on the Plateau, but due to increased demand, development of groundwater from the deeper regional aquifer that supplies these springs has accelerated in the last decade. Currently, Grand Canyon National Park does not add to this demand as its water supply is piped from Roaring Springs, which is on the Kaibab Plateau (North Rim).
Currently, the vast majority of water used on the Coconino Plateau, from Flagstaff to Tusayan, including the water you drink at Grand Canyon, comes from one source: groundwater, either flowing from springs or pumped from wells. Grand Canyon's research on springs and seeps is part of a larger regional examination of the Coconino Plateau's ability to sustain a water supply for its growing population. With the region’s population predicted to double by 2050, there will be a corresponding decrease in water availability and an estimated unmet demand by 2025.
The goal of the South Rim study, which examines springs between the Little Colorado River and Havasu Creek, is to assess to what degree the aquifers that supply Grand Canyon's springs and the Coconino Plateau's growing numbers of wells are connected, and how the effects of current drought and future climate change play a role. Models predict that water pumped from wells will affect Grand Canyon springs, but it is undetermined when, and to what extent. To answer such questions, researchers must gather data to quantify how much water is stored in the Coconino Plateau's aquifers, the age and amount of water discharging from springs and how, when, and where the aquifers are recharged.
Whether replenishing desert willows or hot, thirsty hikers, the value of Grand Canyon’s native waters is immense, and the need to protect them is strong. Grand Canyon's Springs and Seeps Study aims to provide quality science as the foundation for sound management strategies to protect the Park’s native waters.
Plateau Plumbing
Although the Colorado River flows through Grand Canyon's very heart, it is not of this place. The waters are exotic; the headwaters far off in the Never Summer Mountains of north-central Colorado. Precipitation falling on the Coconino (South Rim) and Kaibab (North Rim) Plateaus creates Grand Canyon's only native waters - waters derived in place - as they percolate through porous, faulted, and fractured rock units to discharge later as springs and seeps below the canyon's rim.
Interestingly, no lakes, streams, or ponds form naturally on the plateaus; water is quickly recharged into the fractured Kaibab Formation, which caps the canyon and surrounding area. Below, porous rocks act as reservoirs and faults and fractures as conduits, while some rock units act as barriers to the movement of water. Aquifers are created when porous rock strata are bounded by less permeable rock layers (aquitards) that deter further seepage. When water reaches relatively impermeable layers such as the Hermit and Bright Angel Shales, it moves laterally along their surfaces until it discharges from canyon walls as a seep or spring.
On the Coconino Plateau two regional aquifers exist. The Coconino or "C" aquifer forms 1,000 feet below the plateau in the Coconino Sandstone, Toroweap Formation, and upper Supai Group. The Redwall or "R" aquifer is comprised of the Redwall and Muav Limestones, approximately 3,000 feet beneath the Coconino Plateau. Most plateau wells drill into these two aquifers.
Grand Canyon springs and seeps emerge from canyon walls usually at the contact between an aquifer and an aquitard, and sometimes from ancient cave systems or joints in the rock that have been enhanced by dissolution from the movement of water. If in a canyon bottom, spring water often disappears into streambed gravel, and then reappears downstream in what's known as a canyon floor spring. If the spring emerges on a cliff face, it can form hanging gardens; or if its source has been buried by falling rock, the spring emerges from rock debris on the talus slope below.
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