Development of a prototype rainwater harvesting decision support tool to reduce water and climate-related risks in UK agriculture and horticulture

The drought in 2022 highlighted the severe limitations on farmers and growers having access to reliable water supplies to support high-value irrigated crop production. The protected horticulture sector is particularly vulnerable to water shortages given that all the crop water requirements must be met from irrigation. Rainwater harvesting (RWH) provides an important alternative for alleviating water scarcity for soft fruit businesses whilst also providing flood control bene?ts. While many soft fruit businesses are interested in developing RWH systems on-farm to reduce their dependence on public mains water supplies, and/or direct abstraction, they lack the necessary tools and knowledge to support more informed decision-making and risk management under conditions of increasing water scarcity and climate uncertainty.

The aim of this two-year feasibility project is to therefore develop a prototype web-based tool that will support farm businesses and those engaged in the agricultural and horticultural sectors to better understand the hydrological suitability, technical feasibility, and economic viability for installing rainwater harvesting systems and associated storage to reduce on-farm water and climate risks to production. In this project, the prototype will be developed for the soft fruit sector to assess business benefits (productivity) and scope for reducing environmental impacts (reduced direct abstraction and mains water use) and increased resilience (reduced exposure to water restrictions). Our future ambition is then to up-scale and expand the approach to other agricultural (livestock, poultry) and horticultural (HNS and ornamentals) sub-sectors to maximise impact and industry benefits.

The tool will provide critical farm business support for calculating the most effective RWH system for their circumstances, taking into account local climate as well as farm information on cropped areas, crop mixes, building infrastructure, water sources and available storage. The RWH tool will also assist those farmers with existing RWH installations to evaluate the relative performance of their systems and to identify measures to improve rainwater self-sufficiency; enable farmers that do not have RWH systems to evaluate potential resource benefits, including design and management options, and mains water saving costs; and assist others involved in design of RWH systems for new developments to make informed decisions regarding the trade-offs between RWH performance and water storage capacity to recommend systems that are best suited to the local farm circumstances.