For UK Water and Sewerage Companies (WaSCs), the capacity to innovate capital investment processes, and consequently performance outcomes is fundamental as they seek to deliberately change infrastructure to improve the sustainability of service delivery within a comparatively regulated framework. Innovation is viewed here as being either incremental or radical changes to the products (services) and processes (ways of delivering services) which are typical to the organisation (WaSCs). Product and process innovations may involve changes to some or all of technologies, organisational structure and processes, behaviour and culture, and knowledge and skills within the organisation and its supply chain. This paper sets out to provide an understanding of the factors which both enable and constrain the development and adoption of infrastructure investment process innovations in the context of water utilities concerned with water and sewerage service delivery. The paper documents the process and results from an inductive research programme of participatory action research undertaken within a large, privately owned UK WaSC to facilitate infrastructure investment process innovation. Employee narratives during the innovation process from initiation to adoption decision-making were characterised and analysed. The findings suggest that the development and adoption of asset investment process innovations tends to be skewed in favour of opportunities which align with (i) UK and European Union legislative and regulatory drivers; (ii) WaSC mission policy and goals; (iii) innovation cost advantages over a prescribed period of time; (iv) perceived risks to service provision associated with the introduction of the innovation, and; (v) the extent to which the organisational processes and cultures which act to increase the absorptive capacity of the WaSC to the proposed innovation are already functioning.