Real-time consequences of riparian cattle trampling for mobilization of sediment, nutrients and bacteria in a British lowland river

ABSTRACT

Rivers and their catchments support multiple human needs, necessitating integrated management of land and water resources. Agricultural land use, specifically the impacts of riparian cattle trampling, potentially significantly contributes to damage to river systems. This study addresses a knowledge gap stemming from the paucity of prior research correlating generation of pollutants with cattle activity locally and in ‘real time’. Turbidity, soluble reactive phosphorus and faecal coliforms were analysed at upstream control and downstream impact sites correlated with cattle activity over a 65 m river margin throughout a two-month summer period. Riparian cattle trampling impacted water quality, specifically turbidity and faecal coliform levels. Average turbidity increased by more than 90% between upstream and downstream sites during cattle activity, whilst average faecal coliform counts almost doubled. Findings for phosphorus concentrations were less conclusive, perhaps due to filtration of suspended sediment-bound phosphorus prior to analysis. Illustrative cost–benefit assessment of potential buffer zone installation to exclude cattle from the river margin at the study site, based on values transferred from a relevant published study, found that investment in a buffer zone would achieve a benefit-to-cost ratio of approximately 38:1 with a distribution of broad societal benefits to the farmer, local people and wider publics.

KEYWORDS:

• Cattle trampling
• water quality
• turbidity
• faecal coliforms
• soluble reactive phosphorus
• buffer zone

Acknowledgements

This project was conducted under the International Water Security Network (IWSN). Thanks to Dr Sid and Doreen Jevons and to Jonathon and Deborah Loader for supporting with fieldwork. Simon Browning and Dr Laurence Couldrick from the Westcountry Rivers Trust were generous with their time and knowledge, also loaning automated monitoring equipment and helping to install it and download data. Thank you staff at the Environment Agency, especially Melvin Wood, for provision of water quality and river flow/stage data. The authors also thank their families and friends for support with fieldwork. Professor Chad Staddon offered helpful feedback and support.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This project was funded by Lloyd’s Register Foundation, a charitable foundation helping to protect life and property by supporting engineering-related education, public engagement and the application of research.