Dataset on Continuous Sewer Hydraulic and Pollutant Concentration Observations from 2008 to 2011 Including Precipitation Data, Laboratory Analysis and a Hydrodynamic Model

Overview

This dataset comprises continuous hydraulic and water quality observations from the combined sewer overflow structure at the Graz-West R05 catchment outlet in Austria from 2008 to 2011. The compilation integrates high-resolution in-sewer measurements of flow rate, water level, flow velocity, and water quality parameters including chemical oxygen demand, total suspended solids, and temperature. Measurements were acquired via in situ ultraviolet/visible spectrometry, complemented by laboratory analyses of discrete grab samples. Precipitation data from three tipping-bucket rain gauges and a calibrated hydrodynamic SWMM model of the catchment are included to enable comprehensive analysis of combined sewer system behaviour under varying hydrological conditions.

Methods and approach

In-sewer monitoring utilized radar and ultrasonic sensors for flow rate, water level, and overflow discharge measurements at temporal resolutions of 1 or 3 minutes depending on flow conditions. Water quality parameters were continuously monitored using an ultraviolet/visible spectrometer mounted on a floating pontoon, with discrete grab samples submitted for laboratory analysis to derive locally calibrated chemical oxygen demand values. Precipitation was recorded using time-stamped tipping-bucket rain gauges at three proximal locations. A hydrodynamic model of the catchment was developed using SWMM incorporating geospatial data and dry-weather calibration parameters to facilitate modelling applications.

Key Findings

The dataset encompasses four years of synchronized hydraulic and water quality observations during both dry-weather and wet-weather conditions, enabling the reconstruction of temporal dynamics across multiple flow regimes. Combined continuous in situ measurements with laboratory-verified water quality parameters provides a multi-scale characterization of pollutant transport and accumulation patterns in the combined sewer system. The inclusion of a calibrated hydrodynamic model allows for spatial representation of catchment processes and facilitates comparison between observed and simulated sewer system behaviour across the monitoring period.

Implications

The integrated dataset and hydrodynamic model support the development, testing, and validation of process-based, statistical, and data-driven modelling approaches for simulating combined sewer system behaviour and pollutant dynamics. The availability of long-term, high-resolution observations paired with a calibrated hydrodynamic framework enables systematic investigation of pollutant mobilization, transport, and discharge mechanisms during precipitation events. This combination of field measurements and model infrastructure facilitates advances in quantifying overflow frequency, volume, and pollutant loads characteristic of combined sewer systems under variable hydrological forcing.