About
Tomas Arrieta studies how irrigation changes water quality in farm valleys. He joined Dunmere in 2017 and coordinates the environmental science minor.
He teaches field methods and water courses, and leads the weekly canal sampling program with Biology 340 students.
Before Dunmere, he worked for eight years as a hydrologist for a county water agency.
Courses, 2026–27
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Fall
ENVS 110: Water in the Valley
Lecture and lab. Open to all majors.
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Fall and spring
BIOL 340: Canal Field Study
Weekly sampling on the Alvara Main Canal.
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Spring
ENVS 452: Watershed Hydrology
Senior seminar with a research project.
Photo: Bernd Dittrich on UnsplashResearch
Nitrate in irrigation return flows
Where fertilizer leaves farm fields and how fast it reaches the canal, measured with student sampling teams.
Low-cost water sensors
Testing sensors that small water districts can afford, against lab results.
Selected publications
Fictional titles for a fictional faculty member.
- Weekly sampling reveals short nitrate pulses in an irrigation canal. Journal of Valley Water Studies, 2025. With four Dunmere students.
- Field testing low-cost nitrate sensors for small water districts. Western Water Methods, 2023.
- Teaching field methods with community water data. Journal of Field Science Education, 2021.
