Automated Sampling for Phosphorus in the Lower Boise River

Science Center Objects

For decades, the lower Boise River downstream of Lucky Peak Reservoir has been highly enriched with phosphorus. Too much of a good thing, the high concentrations of phosphorus create a cycle of excessive plant growth, decreased oxygen for fish, and even algal blooms.

In cooperation with the City of Boise, we deployed an automated sample collection device at our lower Boise River streamgage station near Parma, Idaho. Every 49 hours, the device collects water samples that can then be retrieved periodically for laboratory analysis. Automated sampling lets us collect more samples at less cost than standard sampling techniques. 

We are applying the data from these samples to evaluate total phosphorus concentrations and loads and to analyze trends over time. The study is scheduled to continue through Water Year 2026.