A Decentralized Wastewater Treatment System (DEWATS) was built by CURE over the Kuchpura drain using participatory planning processes, in association with the London Metropolitan University and Water Trust, UK. Kuchpura is a peri-urban, low-income settlement of Agra. It is edged by the Kuchpura storm water drain that carried untreated black water from Kuchpura and other upstream settlements to the river Yamuna. The DEWATS used a natural treatment system using gravity flows and bioremediation to process the black water and bring down the BOD levels. It has 5 chambers" a filter chamber to filter debris, a septic tank for primary treatment, a baffle filter reactor for secondary treatment, a reed bed system for the tertiary treatment process and an underground sump for storage. The DEWATS treated 50 kl of dirty water daily, before discharging into the river. Residents reused some of the treated water for construction, non-drinking uses and urban agriculture - the latter nudging a shift from sewage-based to clean water farming. The DEWATS, a first of its kind in Agra and Uttar Pradesh, demonstrated a replicable model of ecological slum development. It resulted in significant health improvements. Land values rose in Kuchpura and people invested in housing renewal. The DEWATS was recognized as a Best Practice by the MoHUA. It also provided the model for the development of the Taj East Drain Improvement Plan.