Scholarship

Contributors

Dr. Joan M. Brehm, Co-Director of the Center for a Sustainable Water Future, Illinois State University

Dr. William Stewart, University of Illinois

Dr. Cory Suski, University of Illinois

Dr. Maria Librada Chu, University of Illinois

Overview

This study focuses on the protection of vital headwater streams to mitigate the negative impacts from rising temperatures and increase the productivity of these waterways that are critical to native fish biodiversity.

Based on current research, these low order streams were found to be surprisingly rich in biodiversity but yet were predicted to be the most fragile and least resilient to future climate change regimes. As a result, this study proposes a place-based examination of select low order streams and associated landowners in the Lake Shelbyville/Kaskaskia River reach of the Upper Kaskaskia River Watershed.

With the collaboration of the Kaskaskia River Watershed Association and the Shelby County Farm Bureau, key landowners will be identified that own land with low order streams identified as being vulnerable to biodiversity loss due to climate change, derived from modeling activities as part of an ongoing USDA project.

Key informant interviews will be conducted with landowners to gather a more in-depth understanding of how they view these streams, their identity as a “good farmer,” and how they view and their willingness to engage in conservation practices that extend beyond water quality protection to include promotion of biodiversity and ecological resilience in the low order streams that dissect much of the large swaths of agricultural land in the Kaskaskia River.

Stream Conservation and Best Management Practices Field Day

We partnered with the Illinois Farm Bureau and the University of Illinois to share information about the significance of headwater streams and practices. 

Learn more about this event

Funding

This project is funded through the Illinois Innovation Network, Sustaining Illinois Seed Funding.

Contributors

Joseph Hoberg, Geology

Dr. Eric Peterson, Project Mentor

Overview

Tracer tests are a common means to discern the hydrologic and transport properties of an aquifer. Conservative ion tracers, such as dissolved salts, are common choices for use as groundwater tracers, but the introduction of large quantities of salts can elevate the concentrations to acute levels for organisms and can create density-driven flows. Rhodamine WT dye is widely used in karst systems but not in Darcian systems.

We explored the questions “Can Rhodamine WT dye be used as a groundwater tracer is a Darcian system comprised of weathered diamicton?”, and “How well does Rhodamine transport compare to the transport of ion tracers?” Six (6) Kg of sodium chloride (NaCl), 4 Kg of sodium bromide (NaBr), and 1 Kg of Rhodamine WT dye (25000 ppm) were injected into a saturated buffer zone (SBZ) via diversion box and drainage tiles. Following the injection, water samples from wells installed in the SBZ were collected and analyzed for dye, Cl, and Br concentrations.

Breakthrough curves for the dye were similar to those of Cl and Br, confirming similar transport dynamics. Inspection of the breakthrough curves for travel times indicated that on average 12 days after injection each well received its largest concentration of the dye (Peak), and two days after peak arrival dye concentrations for all wells had lowered. Peak concentrations for Cl and Br arrived on average 16 and 14 days after injection, respectively.

Identification of the time each ion tracer had left the system was difficult to discern, a storm event occurring 31 days after injection will serve as the upper limit. Breakthrough curves modeled utilizing TRAC simulated travel velocities based upon known hydrologic parameters for the system. Differences among the travel velocities exist among the tracers; however, the differences are minimal.

Overall, the similar arrival times and breakthrough curves of Rhodamine dye, Cl, and Br suggest that Rhodamine dye can be used as a groundwater tracer in weathered diamicton. Future research and replication must be conducted in order to further explore and refine this technique.

Funding

Funding was provided by the Illinois State University Office of Student Research and the Center for a Sustainable Water Future.