Water quality and flow dataset from a degraded peatland catchment: Storm events and treatment pond performance.

This dataset provides high-resolution hydrological and water quality data collected at the outlet of a 16.4 ha industrial cutaway peatland catchment in Ireland. The dataset captures 14 storm events of varying intensities between March 2021 and March 2023, with six events peaking below 15 L/s and eight exceeding 30 L/s. Water samples were collected using an automated ISCO 6712 sampler, paired with flow and temperature measurements recorded at high frequency. The dataset includes parameters such as total dissolved carbon (TDC), dissolved organic carbon (DOC), total dissolved nitrogen (TDN), nitrate (NO₃-N), total ammonia (NH₃-N), ions (Na, K, Ca, Mg, Cl, SO₄), pH, conductivity, and SUVA254 (a measure of carbon aromaticity). Flow data were recorded at 1-5-minute intervals using an ISCO 2150 area velocity flow module, capturing detailed hydrological responses to storm events. Water quality data were collected from a treatment pond receiving effluents from the catchment, allowing for an evaluation of pollutant retention and potential nature-based treatment performance. Grab sampling campaigns were conducted at the pond's inlet and outlet from March-October 2021 and September 2022-April 2023, providing additional data on nutrient and ion dynamics. The pond had a median hydraulic retention time of 15 days, with a highly variable mean of 90 ± 551 days from July 2022 to June 2023. The dataset is structured in three Excel files-Storm Events, Flow, and Grab Sampling-and facilitates analyses of peatland drainage impacts on downstream water quality, storm-driven pulses in pollutant transport, and the effectiveness of treatment ponds in mitigating nutrient and carbon fluxes. By integrating high-frequency flow and water quality data, this dataset enables comprehensive evaluation of hydrological and biogeochemical responses in degraded peatland environments. It is valuable for hydrological modelling applications, runoff-driven nutrient transport studies, and evaluations of climate change effects on peatland effluent dynamics. Researchers can reuse this dataset for comparative studies on storm event hydrochemistry, treatment pond efficiencies, and peatland restoration impacts. The dataset is openly available, offering valuable insights into water quality management and the environmental effects of peatland drainage.