Kandy City is a UNESCO world heritage site. Being the second largest city in Sri Lanka and host to the annual Esala Perahara festival, it has a floating population two to three times its 120,000 permanent residents. Among the city's key landmarks is Kandy Lake, a culturally, environmentally, and economically significant ornamental lake. Nevertheless, inadequate urban development regulation has resulted in serious pollution of the lake. An integrated remedial measure was needed to improve the urban lake's water quality sustainably, for the Kandy community and their cultural heritage. A project was initiated by the University of Peradeniya (UOP), Sri Lanka, and the Nanyang Environment and Water Research Institute (NEWRI), Singapore. It started with modelling of Kandy Lake and community surveys, demonstrated implementation of wastewater management technologies (floating wetlands and an aerobic sequencing batch reactor (SBR)), and initiated community outreach with schools. The project also involved local authorities and government agencies in Kandy, and provided an informal cooperation platform. After project handover on July 10, 2014, further developments were observed in Kandy, including implementation of sewerage and centralised wastewater treatment, rehabilitation of Kandy Lake and the Mid-Canal, and integration of Kandy Lake into the city's development plan and regulations.