Rivers, rainfall and risk: monitoring and managing water quality in the UK under a changing climate

Healthy rivers are a powerful ally in mitigating the effects of climate change; they can protect communities from flood and drought events, and bolster ecosystem and biodiversity resilience (The Rivers Trust, 2024). However, our surface waters (rivers, lakes, estuaries and coastal waters) have historically been used as disposal routes for human, agricultural and industrial wastes, harming water quality. Many of our rivers have also been straightened, had weirs, flow gauging and other infrastructure introduced to facilitate agriculture and to protect against flooding. All of these alterations can degrade habitats, affect fish passage and reduce biodiversity. Consequently, the state of many of our surface waters in England is far from healthy, with only 14% of rivers, 14% of lakes, 19% of estuaries and 46% of coastal waters currently classified as being in ‘good ecological status’ (EA, 2024). What ‘good ecological status’ means is that there has been only a ‘slight change from the natural state as a result of human impact’, whereas ‘moderate’ or ‘poor’ status implies that a moderate or major change has occurred as a result of human impact. This article sets out to explore some of the reasons why water pollution incidents occur and importantly identifies what needs to be done to protect water quality in the UK in the face of climate change. This involved: (i) outlining potential sources of water pollution; (ii) highlighting the effect that rainfall can have on water quality and health; and (iii) concludes by introducing some of the novel water quality monitoring tools and approaches needed to meet this challenge.