CSU ROSS High-Frequency Water Quality Sensor Dataset

This dataset, also known as the Poudre Water Quality Network (PWQN), is an aggregation of real-time in-situ water quality monitoring stations installed across the Cache la Poudre River watershed in Northern Colorado. Operated by the Radical Open Science Syndicate (ROSS) at Colorado State University (CSU) through funding by the City of Fort Collins, City of Greeley, City of Thronton, Northern Water, and NSF Grants, the network utilizes In-Situ Inc. Aqua TROLL multiparameter sondes to collect high-frequency (15-minute) data. Equipment are generally deployed during the ice-free season (March-November) but some early years (2019-2021) may include some winter monitoring.

Current Period of Record: 03/2025 - 11/2025

The publication provides both raw and cleaned (QAQC’ed) datasets in a long-format structure, updated on an annual basis. As of 2025, the parameters collected across the network include:

Water Depth (m), Temperature (°C), Specific Conductivity (µS/cm), Dissolved Oxygen (mg/L), pH, ORP (V), Turbidity (NTU), Chlorophyll-a Fluorescence (RFU), and FDOM Fluorescence (RFU)

The cleaning process involves a multi-stage workflow, including automatic QAQC flags (via the ross.wq.tools R package), calibration drift corrections, and manual technician verification using custom Shiny tools. Cleaned data files include a value_final column and specific modifications codes to denote where drift or biofouling corrections were applied.
While sensor deployment began in 2019, this repository serves as a growing archive that is updated as historical and new data are verified. Comprehensive metadata regarding site locations, sensor methods, and technician field notes are included to ensure data provenance. Corresponding water chemistry grab samples for these sites are available via Zenodo at: https://zenodo.org/records/17887514.