From innovation to action: how Safeswim can inspire the UK's water management

Holly Foreman, the manager of Auckland Council’s Safeswim programme, explores how this World Health Organization-recognised and award-winning initiative is pioneering the management of bathing waters and public health risks. She highlights its role in enhancing institutional accountability and bolstering public trust.

With growing awareness of wastewater discharges to rivers, lakes, and beaches in the UK, important questions are being asked about the prevalence and acceptability of microbial contamination in those waterways and the public health risks it poses to recreational users.

While much attention has been given to overflows from combined sewer systems, microbial contamination also occurs from a range of other natural and human sources, including treated wastewater discharges, septic tank systems, farming, and natural reservoirs such as sediments, marshes, and wild animals (Krupska et. al. 2024, Newson 2024, RAE 2024). In addition to the risks of falling ill after swimming in contaminated waters, there are also concerns about the longer-term public health impacts of exposure to antimicrobial resistant bacteria (EAC 2022, RAE 2024).

The UK Government and the water industry have announced plans to reduce pollution and improve the health of waterways and the natural environment more broadly (DEFRA 2023a and 2023b, Water UK 2024). However, large-scale changes to physical infrastructure systems take time to plan and deliver and government policies can take time to bear fruit. Indeed, the Office for Environmental Protection (OEP) concluded in January 2024 that the government was “largely off track” in meeting its ambitions, targets and commitments for water (OEP 2024). Even if all goes according to plan, the timeframes over which the benefits of these interventions will be realised are relatively long, i.e., 2035 to 2050.

In the meantime, the pollution of the rivers, lakes, and beaches, and the public health risk to recreational users of those waters, continues. How, then, can the public health risk of bathing in the UK’s recreational waters be effectively managed in the interim?

This article highlights the example of Safeswim (safeswim.org.nz), which is a New Zealand programme managing public health risks to recreational water users. Safeswim enables people to make risk-informed decisions on when and where to swim by providing access to real-time, accurate, science-based information on both current and forecast water quality, swimming conditions, and safety hazards for popular coastal and freshwater swimming locations. The programme currently serves the Auckland and Northland regions of New Zealand.

In 2017, Auckland Council realised that its existing compliance monitoring regime, based on similar sampling protocols as those used in the UK, was not fit for purpose and deliberately sought a ‘beyond compliance’ solution for recreational water quality health risk monitoring.

This article provides a brief summary of Safeswim’s evolution and the benefits that the programme has delivered. It then makes the case that a similar approach could benefit the management of bathing waters in the UK.

Auckland and the evolution of Safeswim

Auckland, Aotearoa New Zealand, is a region for beach lovers, blessed with over 200 beaches across three harbours and over 3,200km of coastline (This is around 70% more coastline than Devon and Cornwall put together, see Figure 1 below).
Going to the beach and engaging in water-based recreation – such as swimming, surfing, sailing, or paddleboarding – is an essential part of summer life in the City of Sails. Around 5.1 million people live in New Zealand, with approximately 1.7 million living in Tāmaki Makaurau, as Auckland is known in te reo Māori (the indigenous language of New Zealand).

Figure 1. Key stats and monitored bathing sites in the Auckland region of New Zealand compared to Cornwall and Devon in the United Kingdom.

While the water quality at Auckland’s beaches is generally compliant with swimming guidelines, pollution from stormwater and wastewater networks, and other sources, does sometimes make the water quality unfit for swimming.

Prior to 2017, Auckland Council had assessed water quality at beaches in the Auckland region of New Zealand for over 20 years, primarily using a weekly sampling approach consistent with New Zealand’s guidelines for recreational water quality monitoring (MfE 2003), which reflect the Guidelines for safe recreational water environments published by the World Health Organisation (WHO 2003). The results of the monitoring programme – a long-term monitoring grade similar to the UK beach classification and, when applicable, a short-term surveillance alert condition – were reported on the Council’s website in an unengaging and hard to understand way.

However, monitoring that relies on weekly (or even less frequent) sampling of bathing waters has a number of now well-recognised limitations (Milne et, al. 2017, Neale et. al. 2018, Krupska et. al. 2024). Those limitations mean that short-term pollution events will almost never be detected by sampling and long-term bathing water classifications will never reflect the true public health risk of bathing waters.

Recognising these limitations, Auckland Council was concerned that Safeswim could not provide timely (i.e., advance) warning of the public health risk of bathing and was contributing to a false sense of security about the quality of Auckland’s recreational waters (Neale et. al. 2018). There was also potential for confusion arising from how monitoring results were reported, with the possibility of having a ‘red’ (‘unacceptable risk’) surveillance grade reported alongside a ‘good’ (‘low risk’) long-term grade or vice versa (Milne et. al. 2017).

After demonstrating that predictive modelling substantially outperformed the traditional monitoring approach, Auckland Council subsequently committed to moving Safeswim to a predictive modelling-based approach and implementing proactive communication of public health risk forecasts through a redesigned Google Maps-based public interface (Neale et. al. 2018).

In the absence of regulatory mandate, Auckland Council led a ‘coalition of the willing’ to build the new programme. While Auckland Council provides funding and resources to manage programme delivery, expertise, information, and support is provided by other institutional partners, including Watercare Services Ltd (the water company that supplies water and wastewater services to the Auckland Region), Surf Life Saving New Zealand, Te Whatu Ora Health New Zealand, and Northland Regional Council (which joined the programme in 2022 to provide coverage of bathing waters in the Northland region of New Zealand). Oversight of the science and communication of public health risk is provided by an independent panel which includes New Zealand and international subject matter experts in water quality, public health and microbiology.

Safeswim’s water quality predictions are produced using a range of modelling techniques that differ in sophistication, functionality and information needs to provide the best possible information for each location. Auckland Council has invested in continuously improving the sophistication and robustness of the models each year, through frequent validation and re-calibration exercise. The Safeswim models use the results of water quality sampling and their relationships with environmental factors to predict water quality in real time, calibrated to each individual beach. This means that beaches next to each other may show a different status because water quality is influenced by factors specific to each beach, including tide, wind, wave, and solar radiation conditions, the flow of currents and location of channels, and the nature of discharges to the beach, including natural streams and discharges from stormwater and wastewater networks.

Auckland Council continues to collect water quality samples. In fact, the programme now undertakes more sampling than before, including ongoing routine sampling for model validation and calibration and targeted sampling to support the investigation and monitoring of pollution sources and to demonstrate the outcomes of infrastructure improvements. Through the partnership with Watercare Services Ltd, real-time monitoring information for 55 discharge points from Auckland’s wastewater network have been integrated into the Safeswim system. Alarms at monitored engineered overflow points or pump stations (next to the beach) trigger an automatic override of the models to indicate a wastewater overflow.