The natural landscape of Mahidol University, Salaya is a floodplain area as it is located on former rice fields and water lily ponds. Back in 1974 (B.E. 2517), after the land was owned by the university, the surface water system was proceeded. The first and the second university master plans, 1974 and 1997, have laid out the main canal system, a large canal both around and inside the university. Minor water drainage systems were connectively, comprehensively and effectively installed throughout the campus.
University campus development has greatly altered the canal system, especially wastewater management. Large drainage system was installed near the petanque court, while more ditches were dug on the south of the commercial area in order to connect them with the main system, resulting in systematic and connective water flow. Main, former ditches were dredged for better drainage and reduce water spoilage, while there were newly installed drainage systems, and building of pumping sub-station near the Faculty of Engineering area to alleviate flood during rainy season. University’s center of wastewater treatment system was built to gather and treat wastewater before releasing it out to public canals, reducing wastewater in canals and creating nice environment.