Sustainment and sustainability of the delegated management model of urban water service delivery: an implementation and effectiveness evaluation

Utility/small-scale service provider partnerships are a pro-poor water service delivery mechanism that also reduce non-revenue water and generate employment. Since 2006, a water utility in Kisumu (Kenya) has operated such a partnership programme, the Delegated Management Model (DMM). Implementation science explicitly examines how setting and individuals’ experiences influence public health programme adaptation, but few studies have applied implementation science to water service delivery. This study aimed to assess how contextual changes and evolving actor relationships have influenced DMM programme adaptation, ongoing effectiveness, and long-term sustainment and sustainability. A mixed methods study combined focus group discussions with programmatic document and utility record analysis. The latter captured tariffs, water production, and non-revenue water between DMM inception and 2022. Ten focus group discussions were held with 99 participants, comprising small-scale water providers, kiosk operators, and households in DMM and non-DMM areas. Discussions examined DMM’s evolution, transferability, and scalability. Participants reported recent reductions in DMM small-scale provider profit margins and higher domestic consumer prices after a long period of implementation process stability. DMM delivered most of its original objectives, expanding service coverage and accounting for 6.2% of Kisumu’s connections in 2008, but 18.1% of connections by 2021. However, utility adoption of additional innovations alongside DMM (e.g. district metering) reduced non-revenue water from 67% in 2006 to 25% in 2021. Given these contextual changes but also DMM’s continued delivery of its objectives, we recommend continued DMM investment but also exploring diversification of small-scale providers’ services, such as developing their expertise to deliver wastewater alongside water services.