Located on the peninsula between the Mekong and Nam Khan rivers, Luang Prabang is renowned for its cultural and religious heritage and its blend of Lao and colonial architecture. Tourism linked to this World Heritage status underpins many local businesses and is driving new investment in the city.

Ban Mano (Mano Village) lies within the heritage zone and contains a network of household and communal ponds. These ponds play important social and economic roles – particularly for women, children and older people – by supporting small-scale fish farming, vegetable production and household income. They also provide informal water treatment within the urban drainage system.

However, the ponds are under pressure. Siltation, invasive hyacinth, pollution from greywater and blackwater, encroaching development and upstream hydrological changes are degrading pond health. Some ponds are drying, others have been infilled and built over, and water quality is declining.

What the case study explored

RUCaS collaborated with GRET’s WISE II program, local wetland committees and authorities to co-design options that restore pond health while supporting livelihoods and protecting heritage values. The original study compared a conventional approach – relying largely on septic tanks and existing practices – with a hybrid scenario that introduces NbS to rejuvenate ponds, improve water quality, support productive uses and provide accessible public spaces designed with universal access principles.

As part of this work, RUCaS and partners developed a conceptual plan for Ban Mano that groups ponds into functional zones and identifies several NbS typologies, including constructed wetlands, floating gardens and household-scale greywater treatment systems.

What happened next

Household-scale greywater treatment pilot

One of these concepts was implemented as a household-scale greywater treatment pilot. Following extensive discussions with GRET, the Ban Mano wetland committee and the pond owner, a terraced sub-surface wetland and wicking bed system was selected and designed to treat household greywater before it enters a heritage pond. The system was sized and detailed to fit within a heritage pond frontage and to be built and maintained with locally available materials.

Prototype testing and construction support

To reduce risk and support local construction, a prototype of the greywater treatment system was built and tested at Monash University. This lab prototype was filmed to guide on-site construction, operation and maintenance, and supports training for GRET and the wetland committee.

Environmental monitoring across the heritage pond network

In parallel, an environmental monitoring program was rolled out across Ban Mano’s ponds, using low-cost sensors to track water quality, water levels and, in some locations, air quality and temperature. Workshops hosted with Souphanouvong University, GRET and other partners built local capacity to install, calibrate and interpret sensor data. This monitoring provides quantitative evidence on water quality and pond health, and helps local authorities and communities prioritise future investments across Luang Prabang’s heritage pond network.