CSU ROSS HydroShare ReadMe

This folder contains high-frequency (15-minute) water quality sensor data collected by the ROSSyndicate group at Colorado State University in the Cache la Poudre River Watershed in Northern Colorado, United States.

Publication Structure

This publication is updated annually once data has passed quality assurance procedures and has been both automatically and manually verified by project technicians. As such, we maintain a folder for each year's data and a general metadata folder containing site locations and sensor procedures.

Generally, each year's folder contains a raw (CSU_ROSS_*year*_raw.csv) and cleaned (CSU_ROSS_*year*_cleaned.csv) dataset. Both datasets are provided in long format. In 2025 the following parameters were collected:

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

Each year's cleaned dataset may vary slightly based on available resources, context, and field notes used to verify or modify raw data. Where available, technician field notes will be uploaded with each year's dataset. Specific details for each year are provided below.

2025 Data

The data collected in 2025 was processed using the following script: poudre_sonde_network/data_organization/Process_2025.rmd

Columns in cleaned dataset:

• DateTime_UTC: Date-time in UTC.
• site: Site ID used to identify the site.
• parameter: Parameter name.
• units: Units for the parameter.
• value_raw: Raw measured value.
• value_final: Value for the parameter after passing through QAQC procedures. Erroneous data was removed and, where relevant, raw data was modified to correct for calibration or biofouling errors.
• user_qc_flag: Quality control flag describing why datum was removed or if a data point is flagged/suspect
• modifications: Describes the quality assurance procedures applied to a specific data point, which include:
  • calibration correction: Datum corrected due to a calibration error or calibration drift.
    • See Calibration Correction Tool for details
  • drift correction: Sensor biofouling on Turbidity or FDOM sensors resulted in drift, which was corrected using linear or exponential functions.
    • See poudre_sonde_network/data_organization/drift_correction_2025.Rmd for details
  • manual data exclusion: Datum identified as erroneous by manual technician verification that could not be resolved by the previous two methods. This datum should not be used in analysis.
    • See poudre_sonde_network/shiny_ver_tool for verification tool workflow
  • NA : No modification of datum.

Columns in raw dataset:

• DateTime_UTC: Date-time in UTC.
• DateTime_MST: Date-time in Mountain Standard Time (local time zone).
• site: Site ID used to identify the site.
• parameter: Parameter name.
• units: Units for the parameter.
• value_raw: Raw measured value.
• value_post_cal_corr: Value after applying calibration corrections using the Calibration Correction Tool created by Juan De La Torre.
• value_post_ver: Value after removing data identified by manual verification via the Manual Verification Tool. Also documented in user_qc_flag and qc_status.
• value_post_drift_corr: Value after correcting for sensor drift due to biofouling. For parameters where drift was not corrected, this matches value_post_ver.
• auto_qc_flag: Flags generated by the auto-qaqc system in the {ross.wq.tools} package. These serve as the basis for comparison with human-verified outcomes.
• qc_status: Final status of a data point:
  • OMIT: Datum is considered erroneous and should not be used.
  • FLAGGED: Datum may have minor issues; usable for most analyses but should be excluded if a high degree of accuracy is required.
  • PASS: Datum is considered valid and accurate based on human verification.
• user_qc_flag: Quality control flag describing why a qc_status was applied.
• modifications: Summary of procedures (calibration correction, drift correction, or manual exclusion) applied to the point.

Field Notes (CSU_ROSS_sensor_field_notes_2025.csv)

This file contains field notes collected by technicians throughout the year.

• site: Site identification code.
• visit_comments: Notes on site conditions and work completed.
• DateTime_UTC: Visit start time in UTC.
• sonde_employed: Sensor status following the visit:
  • 1: Sensor was removed following the visit.
  • 0: Sensor was deployed during the visit.
  • NA: No change (sensor remained deployed).
• pre_clean, post_clean, and post_cal values: Values recorded during visits to quantify the effects of cleanings or calibrations.
• cals_performed: List of calibrations performed during the visit.

Metadata

• CSU_ROSS_sensor_methods_metadata.csv: Explains the general calibration methods and sensors used for each parameter.
• CSU_ROSS_location_metadata.csv: Site coordinates, naming conventions, and periods of record. Includes relevant flow gages with discharge records.
  • The column grab_sample_site links to the relevant ID in our published grab sample dataset on Zenodo.
• CSU_ROSS_user_qc_flags.csv: Descriptions of the user_qc_flag flag types used in the raw and cleaned dataset, provides descriptions of the flag, and potential correction pathways.

csu_ross_hydroshare_import.R:

• This script shows a method to import a .zip file downloaded from HydroShare using BagIt. This script organizes the downloaded .zip file and shows users how to access sensor data and spatial metadata.

Additional Resources

• Poudre Water Quality Network: Data collection for long-term monitoring along the Cache la Poudre River through the City of Fort Collins and the primary repository for data cleaning. GitHub | Project Page
• Upper CLP DSS: ROSS work supporting real-time water treatment decision support in the Cache la Poudre River. GitHub
• ROSS CPF Reservoir Study: Investigation of post-fire water quality impacts from the Cameron Peak Fire. GitHub | Project Page
• ross.wq.tools: R package containing functions to support water quality data processing and analysis. GitHub

Most code will not run without proper credentials. Please contact the authors (Sam Struthers, Kathryn Willi, or Juan De La Torre) if you require additional information.