Eric Duffin

Watershed Scientist/Hydrologist

Cirrus Ecological Solution


Eric Duffin is experienced in the field of watershed science including hydrology, water quality, soil physics, fluvial geomorphology, and computer science. He has been employed at Cirrus Ecological Solutions since 2000. During his professional career, he has managed eight TMDL (water quality) projects for the State of Utah (including the Phase 1 Jordan River TMDL), worked with Salt Lake County to develop an ecological health index for the Jordan River. He has written several watershed plans associated with these TMDLs and is currently working on a watershed plan as part of the Lower Bear River TMDL. His areas of specialty include evaluation and analysis of proposed watershed improvements, Total Maximum Daily Load (TMDL) assessments, watershed planning, and providing recommendations for Best Management Practices (BMPs) and Best Available Technology (BATs) to restore impaired water bodies and degraded watershed areas. Eric has also managed field crews, served on numerous NEPA project teams, and provided technical writing and editing for other physical and human-resource disciplines. Eric has lived in Cache Valley since 1990 where he and his wife have raised their family.

Title: Opportunities for Improving Water Quality Using Flow Management in the Lower Jordan River

Friday, May 11, 2:35 PM

Abstract: Poor water quality is a concern in many segments of the Jordan River, a major tributary to the Great Salt Lake. These conditions are being actively addressed by Utah Division of Water Quality and the EPA. Conditions leading to poor water quality in the Jordan River are documented in a Phase I Total Maximum Daily Load study approved by the EPA in 2013. Long-term improvements in water quality will likely require pollutant load reductions from stakeholders at the municipal, county, and regional level. The Jordan River Commission (Commission) and other stakeholders are looking for opportunities to address acute and chronic dissolved oxygen (DO) concerns in the lower Jordan River (LJR) through flow management. This approach could be cost effective and provide additional ecosystem benefits compared to other water quality improvements that focus strictly on reducing pollutant loads. 

In 2014, the Commission completed the first phase of a study investigating the use of flow manipulation as a potential mechanism for increasing DO during the late summer season in the LJR. On the basis of data review and model output, the study recommended field experiments that would manipulate flow at the 2100 South diversion and monitor the resulting downstream effects on DO in problematic reaches. Acquiring sufficient water rights has slowed implementation of the study, but significant progress has occurred during discussions with Utah Division of Water Rights. 

This experiment is unique in the history of Utah water quality remediation and if successful, could lay a foundation for similar work in other watersheds in the state. Flow and water quality are sometimes competing commodities in Utah and any long-term changes in LJR flow management must operate under these conditions. However, analysis of past data has shown that even minor flow changes at the right time, can produce positive improvements in DO. For many reasons, the need remains to identify flow management opportunities that will improve LJR water quality. 

Participants attending this presentation will gain an understanding of how flow management on the LJR has changed over time and the regulations and objectives that guide existing flow management. We will review existing data that identify the influence of flow on water quality in the LJR and describe the progress we have made to date in the LJR flow experiment. We will also identify short-term and long-term opportunities for changes in flow management. 


Why We Care

  • I grew up in Clinton, Utah, not far from the Great Salt Lake. From a young age the lake became a place of recreation, discovery, and solace. Every visit to its shores provides a unique and inspiring experience.

    Justin Wheatley, Alfred Lambourne Prize Participant