Improving UK Regulation of Agricultural Irrigation
Submitting InstitutionCranfield University
Unit of AssessmentAgriculture, Veterinary and Food Science
Summary Impact TypeEnvironmental
Research Subject Area(s)
Earth Sciences: Physical Geography and Environmental Geoscience
Engineering: Environmental Engineering
Economics: Applied Economics
Summary of the impact
Research at Cranfield has underpinned national policies for managing and
allocating the UK's agricultural water resources over the past 20 years.
It has supported major reforms in water policy, abstraction legislation
and drought management. It has done this by modelling spatial and temporal
variations in demand for irrigation, linking this to the financial impacts
of water stress on crop yield and quality, projecting future demand, and
assessing climate change impacts and potential adaptations. It has also
significantly impacted the agri-food sector, helping agribusinesses assess
the viability of irrigation and reservoir investment, encouraging
collaboration, and reducing risks in the food supply chain.
Weatherhead led the first national comprehensive assessment of current
and future water demand for agriculture . Based on multiple linear
regressions analysis by crop sector and region, it eliminated distortion
from inter-annual weather variation to assess underlying growth rates in
areas irrigated and volumes applied. Alternative future agro-economic,
policy and technical changes were then modelled, and their influence on
growth rates estimated. This work underpinned much research on irrigation
water resources in England and Wales for the next two decades.
Weatherhead and Knox integrated this research into a (then) novel
GIS-based methodology, combining abstraction records, government cropping
censuses, irrigation surveys, spatial soils and agroclimatic data, with a
crop water-balance model (developed by Hess). This allowed the modelling
of spatial variations in irrigation water requirements. This was initially
completed for potatoes  and then developed for other nationally
important irrigated commodity crops.
By combining historical records with this novel mapping methodology,
Cranfield researchers identified the underlying spatial trends in areas
being irrigated, the depths of irrigation water applied and volumetric
water use, and predicted future changes in irrigation demand under
contrasting socio-economic scenarios . This research fed directly into
the Environment Agency's (EA) future water resource planning at catchment,
regional and national levels.
By combining these spatial analyses with biophysical and econometric
models on the effect of water stress on crop yield and price variation
with crop quality, the researchers identified the financial costs and
benefits of irrigation, the value of water for agriculture, the spatial
financial impacts of water shortages and abstraction restrictions on
irrigated production, and the economic and societal impacts on the wider
rural economy .
Subsequently, Cranfield researchers incorporated climate change into
their demand forecasts and quantified the potential impacts on crop
productivity (yield) , water use and the viability of rainfed cropping
. This allowed them to advise regulators and the agricultural industry
on the likely impacts and range of adaptation options available in
high-value commodity agriculture.
The research also allowed them to identify irrigation water demand
"hotspots" to support the formation of farmer-led water abstractor groups
and assist the regional development agencies (EEDA, EMDA, SEEDA) in
adopting a strategic approach for targeting grant aid (RDPE) funding for
investment in reservoir infrastructure in water-stressed catchments.
| Key staff
||Water engineering, water resources,
technology, climate change
| Dr JW Knox
||Agricultural systems, water resources,
|Dr TM Hess
||Modelling; hydrology; ecosystem
services; sustainability assessment
References to the research
1. Weatherhead, E K, Place, A J, Morris, J and Burton, M (1993). Demand
for irrigation water. R&D Report 14. National Rivers Authority,
2. Knox, J.W., Weatherhead, E.K. and Bradley R.I. (1996) Mapping the
spatial distribution of volumetric irrigation water requirements for
maincrop potatoes in England and Wales. Agricultural Water Management
31(1-2): 1-15. doi: 10.1016/0378-3774(96)01238-3.
3. Weatherhead, E.K. and Knox, J.W. (2000). Predicting and mapping the
future demand for irrigation water in England and Wales. Agricultural
Water Management 43(2): 203-218. doi: 10.1016/S0378-3774(99)00058-X.
4. Knox, J.W., Morris J, Weatherhead, E.K. and Turner A.P. (2000).
Mapping the financial benefits of sprinkler irrigation and potential
financial impact of restrictions on abstraction: a case study in Anglian
Region. Journal of Environmental Management 58(1): 45-59. doi:
5. Daccache, A., Knox, J.W., Weatherhead, E.K., and Stalham, M.A. (2011).
Impacts of climate change on irrigated potato production in a humid
climate. Agricultural and Forest Meteorology 151(12): 1641-1653.
6. Daccache, A., Keay, C., Jones, R.J.A., Weatherhead, E.K, Stalham,
M.A., and Knox, J.W (2012). Climate change and land suitability for potato
production in England and Wales: impacts and adaptation. Journal of
Agricultural Science 150: 161-177. doi: 10.1017/S0021859611000839.
Details of the impact
Cranfield's research has supported government reforms of the abstraction
licensing system and informed regulation and water management strategies
during periods of drought, helping minimise financial impacts on
agricultural abstractors and economic impacts to the rural economy. It has
underpinned improvements in on-farm water management and efficiency. It
has enabled farmers, processors and retailers to understand the
water-related risks in the fresh produce supply chain. It has also
informed farmers and government on the value of water for farming, and
supported investment in on-farm water storage, and other adaptations to
The research has been undertaken in close collaboration with key
government agencies and departments (MAFF, DETR, Defra, EA, SEPA and
Natural England), and the UK agricultural levy boards. Non-governmental
collaborators included organisations representing the farming industry
such as the National Farmers Union and the UK Irrigation Association,
retailers including Marks & Spencer and Sainsbury's, and environmental
stakeholders such as the Royal Society for the Protection of Birds and
WWF-UK. This broad engagement ensured that the research was suitable for
both informing policy development and supporting the rapidly changing food
and farming sector.
Water Resources Management and Regulation
In the UK, especially eastern England, water for agricultural irrigation
is a critical component of high-value crop production; a major contributor
to the rural economy. More than 1000 farming businesses depend on water to
supply premium quality produce to food manufacturers and retailers,
providing over 30% of potatoes and 25% of all fruit and vegetables
produced in the UK. Together the agri-food industry employs over 50,000
people and contributes some £3 billion annually to the economy of eastern
Cranfield's research has provided the framework for regional and national
actions to improve UK agricultural water management. Our researchers
forecast irrigation water demand for the Environment Agency's water
resource strategies in 2000 and 2008 , and for Defra in 2002 (in the
Climate Change and Demand for Water Revisited study)  and in 2013 (in
support of Defra abstraction reform). They have informed sector-specific
water strategies for the agri-food and horticultural industry (HDC) 
and regional development programmes for agriculture (EEDA).
Our research forms the basis of the procedure used by the Environment
Agency  and the Scottish Environment Protection Agency (SEPA)  to
assess abstraction licence applications; in particular; what constitutes
`reasonable' water allocation for an irrigated farm.
By combining this research with microbiological studies, our work has
informed the development of guidelines for the horticultural industry
where there are public health risks associated with using low quality
river water for irrigation of crops eaten raw .
Internationally, Cranfield research has been applied in key studies for
the European Commission, including assessments of water saving in
agriculture and underpinned the EC's development of a "Blueprint to
Safeguard Europe's Water Resources" .
Climate change impacts and adaptation
We have advised governments and industry clients on adaptation policy in
both the UK and internationally by combining crop growth and irrigation
models. This has provided underpinning data for the UK Foresight study on
Land Use Futures  and to examine the impacts on changes in land
suitability for non-irrigated crops, which directly affects irrigation
demand. A booklet summarising the climate impacts and adaptation options
for the UK potato industry  based on our work was disseminated to over
3000 farming businesses by the AHDB levy board (PCL). This research led to
Knox being appointed Agriculture Sector champion in the government's first
Climate Change Risk Assessment (CCRA).
Improving on-farm water efficiency
The regional development agencies (EEDA, EMDA, SEEDA) have used
Cranfield's research on the economics of reservoir investment and benefits
of irrigation to assess grant applications for investment in farm
reservoirs. Information booklets summarising our research outputs on
improving irrigation efficiency, switching technology, coping with
droughts and reservoir investment have been disseminated by the water
regulator (EA) to over 5000 abstractors in England and Wales, as well as
farming businesses, regulatory agencies, government (Defra) and other
Cranfield's approach has been widely commended by both the water
regulator and farming community. The impacts of our integrated programme
of irrigation research, and strong commitment to knowledge transfer into
the food and farming industry, have been recognised internationally. In
2010, Weatherhead and Knox received the WATSAVE Annual Award "for
outstanding contribution to water savings and water conservation in
agriculture, thereby enhancing the beneficial and sustainable use of this
precious resource" from the International Commission on Irrigation and
Drainage (ICID) .
Sources to corroborate the impact
- EA (2009). Water Resources in England and Wales - current
state and future pressures. Bristol, England. http://preview.tinyurl.com/eawaterres2008
- Downing, T., Butterfield, R., Edmonds, B., Knox, J.W., Moss, S.,
Piper, B., and Weatherhead, E K. (2003). CCDeW: Climate change and
demand for water revisited. Final Research Report to DEFRA. Stockholm
Environment Institute, Oxford Office, Oxford.
- Knox, J.W., Kay, M.G., Weatherhead, E.K., Burgess, C., Rodriguez-Diaz,
J.A. (2009) Development of a water strategy for horticulture. Project CP
64 Final Report, Horticultural Development Company, Stoneleigh. http://www.hdc.org.uk/project/hdc-development-water-strategy-horticulture
- Rees, B., Cessford, F., Connelly, R., Cowan, J., Bowell, R.,
Weatherhead, E.K., Knox, J.W., Twite, C.L., and Morris, J. (2003).
Optimum use of water for industry and agriculture; Phase III Best
practice manual. R&D Technical report W6-056/TR2. Environment
- SEPA (2013) Supporting Guidance (WAT-SG-70) Sector-specific Guidance:
Agriculture. Scottish Environmental Protection Agency, Stirling. http://preview.tinyurl.com/WATSG70
- Knox, J.W., Daccache, A., Tyrrel, S.F. and Weatherhead, E.K. (2011). A
geospatial approach to assessing microbiological water quality risks
associated with irrigation abstraction. Water and Environment
Journal 25(2) 282-289. doi: 10.1111/j.1747-6593.2010.00227.x
- Farmer, A., Dworak,T., Bogaert, S., Berglund, M., Zamparutti, T.,
Interwies, E., Strosser, P., Stanley, K., Schmidt, G., Cools, J.,
Hernández, G., Vandenbroucke, D., Cherrier, V., Newman, S. (2012)
Service contract to support the impact assessment of the Blueprint to
Safeguard Europe's Waters: Assessment of policy options for the
blueprint. Final Report.
- Weatherhead, E.K., and Howden, N.J.K (2009). The relationship between
land use and surface water resources in the UK. Evidence Review 5 for
Foresight Land Use Futures Project 2010. http://www.bis.gov.uk/foresight/our-work/projects/published-projects/land-use-futures/reports-and-publications.
- Knox, J.W., Daccache, A., Weatherhead, E.K., Stalham, M (2011).
Climate change and potatoes. An information booklet produced for PCL
(AHDB), Cranfield University. http://www.potato.org.uk/publications/climate-change-and-potatoes
- ICID Awards http://www.icid.org/awards.html#tech