Flooding Issues in Maiti Ghar Area Caused by Engineering Flaws and Encroachment in Water Flow Zones
A technical review reveals that flooding during the monsoon season in the Maiti Ghar area is primarily due to engineering errors, sewer encroachment, and the destruction of natural water absorption zones. Narrowing of sewer pipes leads to blocked water flow and bottlenecking on roads, while reverse flow in the Tuku Cha river contributes to flooding. The report recommends long-term solutions, including constructing large underground water storage tanks and redesigning sewer capacities.
Kathmandu, July 24 – A study has identified the main causes of flooding in the Maiti Ghar Mandala area during the rainy season as technical faults in surrounding infrastructure, encroachment into water flow areas, and loss of natural water absorption zones. Following flooding after the onset of heavy rain, on July 19, an inspection team led by Sunita Dangol, Acting Chief of Kathmandu Metropolitan City, along with heads and representatives of development partners and service management agencies, conducted an on-site review. Dangol instructed officials to submit a technical report based on their findings.
In compliance with the acting chief’s directive, a committee was formed under the coordination of Ram Bahadur K.C., Deputy Secretary and Head of the Response Branch at the National Disaster Risk Reduction and Management Authority. The team included senior Kathmandu municipal engineer Jeevan Regmi, Department of Roads engineer Purushottam Bhandari, and Manager Ujwal Shrestha from Kathmandu Valley Water Supply Limited.
The report highlights serious engineering errors in the sewerage system of the Maiti Ghar Mandala area. The main inlet pipe measures 90 centimeters in diameter but narrows down to 60 centimeters in the lower section. The pressure from water entering through the upper, wider pipe cannot be handled by the narrower lower pipe, resulting in a bottleneck and water accumulation on the streets. Additionally, when the surface level of the Tuku Cha river rises, sewer water should flow into the river; however, backflow occurs toward residential areas and roads, exacerbating flooding in Maiti Ghar.
The report also identifies physical infrastructure, environmental factors, and urban development as contributing reasons for the problem. Previously, open spaces around Maiti Ghar square served as natural water catchment areas that facilitated underground absorption of rainwater. However, construction of large buildings such as the Kathmandu District Police Office and the Government Attorney’s Office in these areas has covered them with concrete, disrupting these natural absorption processes. This has led to excessive surface water runoff, which concentrates in the Maiti Ghar square, the technical team concluded.
Encroachment has also played a significant role in the flooding problem. During the inspection, it was found that some private and government structures have been built inside sewer channels, obstructing regular cleaning efforts. The presence of plastic waste, bottles, stones, and gravel blocking sewer pipes has led to restricted water flow. To address this, Acting Chief Dangol has instructed local administration and partner agencies to remove all such obstructions promptly.
The report suggests both immediate and long-term measures. In the short term, it calls for clearing obstructions from sewer outlets, raising the height of manholes, and prioritizing regular cleaning. For long-term solutions, it recommends constructing a large underground water storage tank on public land in the Maiti Ghar area or within the old Ministry of Health premises. This tank would temporarily store excess rainwater before gradual drainage.
Additional recommendations include installing non-return valves at the outlet of the Tuku Cha river to prevent backflow, conducting comprehensive GIS mapping of the entire valley’s sewer network, and redesigning the sewer capacity based on the Maiti Ghar catchment area. The report also emphasizes the necessity of improved coordination among road, water supply, sewage, and electricity agencies to end repetitive digging and construction, calling for the development of an integrated infrastructure management system.
