<p>Sicily served as a nexus of connectivity in the ancient Mediterranean, with new ideas and technologies – especially concerning water – emerging from collaboration and competition between multiple communities. An area of ongoing investigation is understanding how mortar technology developed on the island, and what factors influenced its dissemination. To address these questions, the waterproof linings of nine water features from the neighbouring sites of Selinunte (ancient Selinous) and Agrigento (ancient Akragas) were collected. Both sites originated as Greek colonies, but experienced episodes of Punic and Roman hegemony, facilitating the emergence of complex hydraulic networks inspired by multiple socio-technological influences. To investigate the effect of these different communities, 22 mortar specimens that dated from the mid-6th century BCE to the 1st century CE were studied using archaeological and instrumental techniques that included microscopic, digital image and elemental analyses, as well as a novel application of µX-Ray Fluorescence Microscopy (µXFM). Using the multiple data sets produced by these different analyses, this study established a preliminary chronology of waterproof lining technology at Selinunte and Agrigento. It also contextualised evidence of technological change within the broader history of ancient Sicily to demonstrate that growing interconnectivity facilitated the development and transmission of complex hydraulic technologies in the ancient Central Mediterranean.</p>