The River Loobagh is a tributary of the River Maigue…
Eden Demonstration Test Catchment, UK
Introduction
A two-day visit to England was made by Marie Archbold, Donal Daly, Jenny Deakin, Paddy Morris (all EPA) and Deirdre Fay (DAFM) on 29th – 30th April 2015. The purpose was to learn from the work of the Eden River Trust in Cumbria and the Eden Demonstration Test Catchment (DTC) research, and the research being undertaken by the Allerton Project, run by the Game & Wildlife Conservancy in the Eye Brook catchment, Loddington, Leicestershire.
Objective
The main objective was to derive comparisons between catchment research and characterisation being carried out in the UK and that being carried out in Ireland by Teagasc in the Agricultural Catchments Programme and by the EPA in their Catchment Science and Management Unit.
The purpose of this article is to reflect on the knowledge gained during the trip in the context of the DAFM funded Agricultural Catchments Programme, with a particular focus on the River Eden Demonstration Test Catchment (Eden DTC).
The Eden Demonstration Test Catchment (DTC)
The River Eden Demonstration Test Catchment (Eden DTC) is a DEFRA funded research project. The aim of the project is to assess if it is possible to cost effectively mitigate diffuse pollution from agriculture whilst maintaining agricultural productivity. The project is working in three focus catchments within the River Eden catchment, selected to represent a range of land uses, physical characteristics and weather. The focus areas are in the Dacre, Morland and Pow catchments. Each catchment has an area of approximately 10 km2. The projects involve monitoring the stream water quality and biology and looking at how the catchment responds to storm events. Working closely with farmers in the catchment to test a range of mitigation measures in real catchment situations is an important element of the project.
The project aims are three fold:
- To produce evidence to test the hypothesis that it is possible to cost effectively reduce the impact of agricultural diffuse pollution to water on ecological function, while maintaining food security, through the implementation of multiple on farm measures.
- To develop a research platform to host collaborative research.
- To develop a common vision for catchment management centred around local knowledge and understanding.
Each focus catchment was selected to represent the full range of natural and anthropogenic variation across the Eden catchment as summarised below:
Morland Catchment
- Limestone/sandstone/mudstone
- Sandy clay loam/clay loam
- Artificial drainage
- 87% grassland, 71% improved
- Dairy/beef/sheep
- 1150 mm rainfall
Pow Catchment
- Limestone/sandstone/mudstone
- Sandy clay loam/clay loam
- Artificial drainage
- 46% improved grassland, 37% arable
- Intensive dairy/beef/sheep/pigs/poultry
- 810 mm rainfall
Dacre catchment
Dacre Catchment
- Upland
- Volcanic andesite, glacial till
- Sandy clay loam/clay loam
- 80% grassland, 16% woodland
- Extensive sheep grazing
- 1570 mm rainfall
Catchment pressures include intensive farming, erosion of river banks by livestock, flash flooding from hills and lowland drainage, abstraction, pollution and silting, and climate change and increasing frequency of floods and droughts.
A variety of changes in farm and land management are being trialled in the Eden DTC to reduce the impacts of diffuse pollution on surface water and groundwater. These are being delivered through advice and support on soil and nutrient management, tailored to the specific geography and types of farm practice. Researchers and advisors are working with farmers to identify flow pathways, specific problems and ‘hotspots’ such as vulnerable fields and hard standings.
Catchment monitoring includes the collection and telemetry of water quality data such as phosphorus, nitrogen, ammonium, turbidity, pH, electrical conductivity, water temperature, chlorophyll and dissolved oxygen, as well as hydro-meteorological data such as rainfall, river stage/flow and other meteorological parameters. In addition non-telemetered data is collected such as monthly spot samples, storm samples, biological samples, borehole levels and chemical analyses of borehole samples, soil samples, faecal indicator organism samples, farm business and farmer attitude surveys.
Each focus catchment contains 2 sub-catchments, a control catchment and a mitigation catchment, each with an area of approximately 2 km2. For each mitigation sub-catchment a conceptual approach is adopted based on source, mobilisation, delivery and receptor.
Eden DTC Water Framework Directive Classification
- Development of nutrient management plans targeting dirty water, slurry, manure and fertiliser spreading.
- Working with land managers to deliver large scale investment in farm infrastructure such as slurry and silage storage and manure management processes.
- Installing drains, ponds, lagoons and stone barriers where required.
- Improvement of livestock and machinery tracks to prevent erosion and rapid transfer of pollutants to watercourses.
- Establishing riparian buffer strips and stream-bank fencing to exclude livestock. Fencing may be coupled with some carefully targeted additional options such as constructed wetlands, and settling ponds for sediment and associated nutrient removal.
- Reduced cultivation methods such as strip tillage and the use of cover crops to reduce bare soil after harvest and to take up residual nitrogen.
- Biobeds to reduce pesticide pollution from sprayers. The sprayers are washed down on a hard standing and the polluted water broken down in a bed of straw, soil and peat.
- Initial research findings are showing positive effects in the mitigation sub-catchments, with a 28%, 39%, 27%, and 31% decrease in total phosphorus, total reactive phosphate, nitrate nitrogen and ammonium nitrogen respectively, as well as a 35% increase in suspended solids.
Concluding remarks
A particular success of the Eden DTC of working is the close working relationship with farmers to test a range of mitigation measures in real catchment situations. This approach is an invaluable element of the project, and fosters a meaningful exchange of knowledge between researchers, advisors, farmers and policy makers. It is recommended that a similar research based mitigation approach is considered alongside the existing research based monitoring programme, in any subsequent funding of the Agricultural Catchments Programme to ensure a simultaneous focus on maximising the uptake of best management practices by farmers, as well as the development of national sustainable intensification policies.
