Rainwater harvesting on animal farms as a response to the increasing water deficit in agriculture

In the context of growing water scarity in agriculture the harvesting of rainwater from livestock buildings could be seen as a new opportunity. Based on the National Agricultural Census (2020), rainfall data (1991-2020) and the opportunity and investment costs related to the installation purchase, a prognostic analysis was conducted. The analysis revealed the immense potential of farms for rainwater collection. In Poland there are 201,980 cowsheds, 65,088 pigsties and 96,435 poultry houses, representing a total area of 8,820 ha, which allows additionally to retain over 41 million m3 of water per year. This amount will cover only 15% of the livestock total water demand. It should be noted that the average economic efficiency (EF) value for the entire country was 81.6%, and the differences in the analyzed animal groups reached a moderate level (CV=14.7%±0.1 depending on the groups). The unit price of tap water was the main determinant of the highest EF of investment in rainwater harvesting (RWH) in particular voivodeships.