Process evaluation of an urban piped water supply infrastructure improvement programme in a cholera hotspot

Abstract

Large-scale investments in water supply infrastructure will be required to achieve Sustainable Development Goal (SDG) 6. Safely managed water services are also a central element of global strategies to prevent cholera and diarrhoeal diseases. However, evidence remains scarce on how to efficiently improve piped water services in the complex settings that bear high disease burdens and where infrastructure investments are most needed. We conducted a process evaluation of a large-scale water supply infrastructure improvement programme in the town of Uvira, an endemic cholera hotspot in South Kivu, Democratic Republic of the Congo. Considering three evaluation domains – context, implementation of the intervention, and population response –, we assessed the validity of the programme’s theory of change and its underlying assumptions. Information sources included documents related to construction works and to the programme implementation, operational and billing records from the water system operator, and household surveys, covering the period from 2014 until 2021.The programme did not achieve the expected improvements in the water supply service available to the population of Uvira during the evaluation period. Contextual challenges included major events such as extreme flooding in early 2020 and the Covid-19 pandemic. Issues related to the electricity supply and the rise of Lake Tanganyika emphasise the need for cross-sectoral approaches and consideration of climate change in the planning of water supply infrastructure. Implementation challenges underlined a need for capacity strengthening alongside infrastructure improvements. Population response elements revealed the importance of designing affordable interventions and of taking informal practices such as the sharing of household taps into account. The programme was a good example of early engagement with researchers. Pragmatic evaluation approaches combining relevant methods should be adopted for the generation of useful scientific evidence from complex programmes in order to inform and enhance the effectiveness of future infrastructure investments contributing to progress towards SDG6.

Improved water supply infrastructure to reduce acute diarrhoeal diseases and cholera in Uvira, Democratic Republic of the Congo: Results and lessons learned from a pragmatic trial

“…The estimated volume of water delivered remained under 20 L per capita per day during >95% of the observation period and showed a decreasing trend, as the number of connections to the network substantially increased (with the “accessibility” component of the index reaching 100% in four clusters) while production capacity remained limited (Fig B in S1 Fig ). Pumps operated 58% of the time on average and electricity supply deteriorated over time, leading to reduced hours of operation and more frequent service interruptions [ 16 ].…”

“…Concretely, in order to achieve public health and other benefits, programmes aiming to prevent diarrhoeal disease and cholera in urban settings through an improved piped water supply should: (i) design and invest in infrastructure solutions that can deliver a “safely managed” water service in the long term, resilient to a changing climate; and (ii) integrate sufficient technical and organisational support to water utilities to ensure an adequate system operation. In the Uvira context, where water service intermittence is closely linked to electricity supply issues, our results also call for enhanced cross-sectoral planning and coordination [ 16 ].…”

“…We designed a pragmatic stepped-wedge, cluster randomised trial (SW-CRT) to assess the impact of water supply infrastructure improvements on acute diarrhoeal diseases and cholera in Uvira, with concurrent process and economic evaluations [ 15 ]. This manuscript focuses on the epidemiological analysis of trial data; the process evaluation, including household survey results on domestic WASH practices, and the cost-of-illness study are described in detail elsewhere [ 16 , 17 ].…”

“…This led to a 6-week interruption in the water supply service and a sustained reduction in the production capacity of the water treatment plant–until the installation of a new water intake, commissioned in January 2024. A survey of 148 households suggested that a minority of the population (9%) were still using emergency water supply three months post-flooding, in July 2020 [ 16 , 25 ].…”

“…Towards the end of the infrastructure improvement programme, in a survey of 528 households conducted in September 2021, REGIDESO taps, either outside (42.6%) or in the compound (18.6%), and rivers (30.9%) were most commonly reported as main water sources [ 16 , 26 ], suggesting a slight increase (+9.2 percentage points) in the proportion of households using REGIDESO taps compared to the situation in 2016/17.…”