Many see the problems across Zambia’s capital Lusaka and are ready to act, but there is not a single entity that can address the various environmental challenges on its own. Isolated efforts risk having only limited effect on the complex water situation in Lusaka. The formation of the Lusaka Water Security Initiative (LuWSI) in 2016 resulted from the insight that the complexity of issues threatening Lusaka’s water security requires multi-stakeholder collective action. LuWSI is now recognised as a key driver of water security in the city, with a steadily increasing membership of currently over 30 partners.