Given regulatory developments, it is imperative that water businesses implement effective customer engagement strategies. Among other options, Facebook offers enormous potential given the ability to connect with customers, involve customers in the co-creation of content, obtain real-time feedback on customer preferences and promote water conversation behaviours. This paper examines how effectively 20 large Australian and U.K. water businesses are using Facebook to engage customers. It also identifies how these firms can improve Facebook engagement by optimising posts type, timing, content, frequency and other factors. The total sample included more than 300,000 responses to nearly 17,000 posts between 2010 and 2017. Rapid growth in the utilisation of Facebook by water businesses was observed given the number of posts and customers engaging with this content. The results of the analysis of popular posts identified innovative ways some water businesses are using Facebook posts to promote the health benefits of tap water consumption, water conservation behaviours and responsible wastewater practices. Despite the trends, most firms still make less than one post per day and of those customers who have engaged, most have done with a single response. Further analysis revealed that few posts, and only a relatively small number of customer comments, pertained to water pricing matters. To promote engagement, water businesses must improve post regularity, the degree to which they moderate Facebook discussion, the utilisation of videos and photos, and further consider the underlying content of posts.