Truckee River Microplastic Levels Rose During Spring Runoff

Researchers found that high spring flows in 2023 significantly increased the concentration of microplastics in the river.

Updated on Oct. 13, 2026 in Environmental

Bold flat-color editorial illustration of a vessel containing suspended particulate matter, representing the rise of microplastics in local river ecosystems. — Microplastic levels in the Truckee River increased nearly tenfold during the 2023 spring runoff as rising waters mobilized accumulated plastic particles. AI Illustration. Upload story photo >

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Researchers at the Desert Research Institute found that microplastic concentrations in the Truckee River rose nearly tenfold during spring runoff in 2023 compared to the previous fall. The increase occurred as high water levels mobilized plastic particles that had accumulated along the riverbanks during drier months.

Why it matters

Understanding how seasonal water flow impacts plastic mobilization is crucial for managing water quality in the Reno area. This process demonstrates how environmental conditions directly influence the movement of pollutants through local ecosystems.

The study measured a shift from 0.4 particles per liter in fall to 3.7 particles per liter during spring, representing a nearly tenfold increase in concentration. Observed plastics included PET, polypropylene, and polyethylene.

The players

Desert Research Institute

This research organization specializes in atmospheric and earth sciences and conducts studies throughout Nevada.

The details

High flow events during spring runoff trigger the re-wetting of riverbanks and the resuspension of plastic debris into the water. Researchers noted that particle levels jumped from a maximum of one particle per quart mason jar in the fall to 10 particles per jar in the spring.

Researchers sampled the Truckee River during low flows in fall 2022.
Researchers conducted high-flow sampling in spring 2023.

The Big Picture

This finding builds upon the research foundation provided by the Desert Research Institute by specifically identifying how seasonal hydrological cycles drive pollutant transport. It moves the discipline toward a more granular understanding of how land-based plastics enter river systems.

This research highlights that water quality fluctuations in the Truckee River are highly dependent on seasonal runoff patterns. Residents and local water managers may need to account for these periodic increases in plastic particle concentrations during high-water events.

The takeaway

Plastic debris accumulated on riverbanks during the dry season poses a recurring risk to water quality once the spring melt begins. Implementing measures to reduce litter near the river throughout the year may help mitigate these seasonal spikes in microplastic levels.