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Demonstration Test Catchments: Catchment scale testing of measures to mitigate diffuse agricultural pollution on the Wensum - WQ0212


The legacy of intensive farming practices in northern Europe has led to the contamination of rivers, lakes and groundwaters and can potentially cause the over-enrichment of aquatic ecosystems leading to a loss of biodiversity. At the same time, society has a need for clean drinking water supplies for which it is expensive to remove high concentrations of nitrate, phosphate and pesticides derived from agricultural runoff and sewage treatment works. These contaminants are diffuse in their source and distribution and are therefore difficult to control, even though the UK is legally bound to meet the conditions of various European directives including the Drinking Water Directive, Nitrates Directive, Habitats Directive and the Water Framework Directive. A principal challenge in managing the environment for better water and environmental quality is the need to encourage land use practices that reduce diffuse pollution in a largely rural environment, while at the same time recognising that rural communities depend on an economically viable agricultural sector.

Good examples of approaches to catchment management that are able to balance the higher level regulatory requirements of government and the local knowledge of farmers and residents are known internationally, for example the provision of unfiltered drinking water to New York City maintained from surface reservoirs in the Catskills. In this example, farmers and householders employ land use practices such as ‘buffer strips’ along stream corridors that prevent nutrient and sediment runoff to water courses. These types of land use ‘measures’ are best developed in discussion with stakeholders and practitioners, with their success determined by data collected by water sampling and ecological monitoring of surface waters and groundwaters.

In the UK, catchment science and management is less well developed and co-ordinated and further research is needed to understand the types and effectiveness of single and packages of land use measures for reducing diffuse pollution runoff. In addition, past research has provided scientific knowledge of processes that control the transport and fate of agricultural runoff, both dissolved in water and attached to sediment particles, but has been uncoordinated in approach. Hence, this proposal will learn from international experience and past research and establish a research platform, to be known as the Wensum Alliance, which will coordinate research as part of the Defra Wensum Demonstration Test Catchment (DTC). Our aim is to foster a research group that will promote learning of how to develop and implement mitigation measures, such as reduced fertiliser application rates, that can be demonstrated to deliver a healthier environment while at the same time maintaining rural livelihoods.

The Wensum DTC will be part of a wider DTC initiative in England and Wales that will provide wider learning through the comparison of approaches and results in areas with different soils, hydrology, climate and land use. In the Wensum DTC, the first component of research is to design and set-up a monitoring network for measuring flows, sampling surface water and groundwater and collecting ecological data. Our approach will be to work with Environment Agency and Defra officers to coordinate research within current monitoring programmes in the Wensum catchment, such as the English Catchment Sensitive Farming Delivery Initiative. The design of the monitoring network is to select three potential sub-catchments in the Wensum that have known problems with nitrate, phosphorus and suspended sediment runoff and to install pairs of automatic monitoring stations in smaller ‘mini-catchments’ at the farm scale. In each sub-catchment, one mini-catchment will be used as a control and the second will be ‘manipulated’ to test the effectiveness of land use measures in terms of improving aquatic ecosystems, but also in terms of assessing their practical feasibility for farm businesses.

The Wensum Alliance will adopt an integrated scientific approach combining the skills of environmental scientists, social scientists and practitioners. The results generated by the Wensum Alliance will be transmitted to a national data infrastructure platform (the Virtual Observatory) as well as communicated to our research partners and stakeholders in the catchment through a website, newsletters, regular meetings and agricultural events in order to promote knowledge transfer and exchange. The overall success of the Wensum Alliance will be realised both now and in the longer term in demonstrating the setting-up, running and delivery of land use measures that maintain the sustainable use of natural resources in a catchment and which are robust enough to adapt to future climate and environmental change.
Project Documents
• ROAME Document : WQ01   (200k)
Time-Scale and Cost
From: 2009

To: 2015

Cost: £2,612,839
Contractor / Funded Organisations
University - East Anglia
Diffuse Pollution              
Environmental Protection              
Sustainable Farming and Food              
Water Pollution              
Water Quality