Merrimack River
water quality.

What you can explore

Open the interactive Rivistry dashboard to view available measurements, station context, historical charts, reference lines, and recent weekly highlights for Merrimack River.

Read the context

River measurements can vary with season, rainfall, temperature, flow, sampling location, and method. Rivistry presents them as evidence to understand and investigate—not as a standalone safety determination.

For the original monitoring information, visit NHDES river and lake monitoring ↗.

Keep following changes

Weekly River Updates compare new observations with previous readings, recent baselines, trends, and applicable reference values.