Flagstaff Chapter

Join us for a presentation by Hannah Chambless, Hydrologist with Grand Canyon National Park, on Grand Canyon North Rim Dye Trace Study. Talk starts promptly at 6:30

Date: Friday, August 7

Time: 6-8 PM (talk starts promptly at 6:30)

Location: Mother Road Brewery

Cost: $5 for members and non-member students; $10 non-members. Appetizers included!

About Hannah Chamberless:
In 2011, I left Georgia to study Environmental Geoscience at Boston College and stayed after my undergraduate degree to receive my Master’s in Geology there in 2018. My research at Boston College involved analyses of wastewater injection-induced seismicity in Oklahoma related to oil and gas activities, but I spent a lot of my time assisting with field data collection for research projects in the Hydrology and Geomorphology groups to bolster my experience in Hydrology. In 2018, I accepted an internship through the Geoscientists-in-Parks (now Scientists-in-Parks) program at Grand Canyon National Park, where I worked on an overflight noise monitoring project. During this time, I frequently cross-trained with the Hydrology program at Grand Canyon, and in 2019, I accepted a position as a full-time Hydrologic Research Technician under a cooperative agreement with Northern Arizona University and Grand Canyon National Park under Dr. Abe Springer. This position was integral to my goal of pursuing a career in Hydrology. In 2021, I accepted a federal position as a Hydrologic Technician with Grand Canyon, and in 2022, I became the park’s Hydrologist where I still am today.

Abstract:
It is imperative to understand the quantity, quality, and vulnerability of groundwater below the North Rim of Grand Canyon National Park to inform park drinking water planning and to protect sensitive spring ecosystems. Dye tracing addresses these objectives by delineating flow paths, rates, and source areas from sinkholes on the North Rim to springs in the canyon and by assessing any annual changes in these characteristics. Fluorescent, food-grade dyes were
injected into three sinkholes in April 2024 and two sinkholes in March 2025, all prior to snowmelt. Three of these five sinkholes were repeated sites from a 2015-2017 dye trace study. Charcoal receptors were placed at 43 spring and stream sites in the canyon in January 2024 and were exchanged every 4-8 weeks through April 2026 to determine if, when, and where dyes emerged. Two of the five dyes was detected in the park’s drinking water source, Roaring Springs, and
two of the dyes were detected at springs flowing into the future drinking water source, Bright Angel Creek.
Results provide additional evidence for s
nowmelt entering long-term groundwater storage and suggest annual heterogeneity of flow paths. Two of the dyes injected in 2024 were first detected during the snowmelt pulse and then continuously through baseflow for over a year. One of the dyes injected in 2025 was first detected during the snowmelt pulse and then through baseflow for another 2-3 months. Two of the three repeated dye injection sites resulted in dye detections at different springs or different timing than the previous detection locations. PlanetLabs satellite, in-situ game camera imagery of snowpack, and the earliest detections of dye at springs indicate a travel time from infiltration to discharge of 2-26 days, though continuous water quality data suggests travel times on the shorter end of that range. The timing, location, and duration of dye detections will be used with snowpack and groundwater flow data to compare flow paths across different snowpack conditions, to delineate source areas, and to calculate annual water budgets at springs.