The Bhutanese Leading the way.
Despite concerns over waterlogging and sewage overflow during the monsoon season in Thimphu, the Thimphu Thromde has claimed that the city’s drainage systems function well under normal conditions and that comprehensive upgrades are on the way.
Lyonpo Chandra Bahadur Gurung reading out a reply by Thimphu Thromde said that while problems surface mainly during heavy rainfall in vulnerable zones such as Olakha and Zilukha, the situation is under control. He said, “The drainage works perform well in normal conditions. The Ministry of Infrastructure and Transport and Thimphu Thromde are working together to ensure sustainable solutions through the upcoming projects.”
The upcoming works are being implemented under the Enhancing the Climate Resilience of Urban Landscapes and Communities in Thimphu-Paro region of Bhutan (ECRUL Project), which will roll out in phases from 2025 to 2028. The initial phase, set to begin in mid-2025, focuses on the redevelopment of Primary Drain II in the old city areas of Motithang, Changangkha, and the city core. With Nu 16.2 million (mn) allocated, the works will include 2.6 kilometers of covered drains, improvements to catch pits, installation of waste traps, and the introduction of nature-based solutions like rain gardens and retention ponds.
The project will then expand in 2026 to cover Upper and Lower Chubachu as well as the stretch between Chang Khorlo (RICB Colony) and Kaja Throm, with combined investments of over Nu 50 mn. By 2027, all secondary drains across the city will be redeveloped at a cost of Nu 102.4 mn, followed by household connection drains in 2028 with a budget of Nu 51.8 mn.
Sewerage expansion is also being planned alongside the drainage upgrades. Thimphu Thromde has already completed Nu 17.9 mn worth of network connection and expansion works in the fiscal year 2024–25. Additional connections are scheduled for 2025–26, while the broader citywide sewerage proposals are integrated into the Thimphu Structure Plan (TSP) 2023–47, for which MoIT is the lead agency.
Officials from MoIT, Thimphu Thromde, and the Department of Human Settlement are currently assessing the city’s most vulnerable areas to prioritize urgent action. They stressed that these collaborative efforts are not only designed to solve short-term blockages and overflows but also to build a long-term, climate-resilient drainage system for Thimphu’s growing population.
While Thimphu waits for these upgrades, open raw sewers along roads remain a significant public hazard. During the monsoon, schoolchildren are forced to walk along roads filled with raw sewage and open sewer manholes, putting them at serious risk of injury or even fatalities, and exposure to disease.
Health experts warn that exposure to raw sewage can spread waterborne diseases such as cholera, hepatitis, and gastroenteritis. The stench and contamination also make surrounding areas unhygienic, affecting residents’ quality of life.
Environmental impacts are equally concerning. Raw sewage flowing into rivers and streams harms aquatic life, disrupts ecosystems, and contaminates water sources used for irrigation and washing.
Authorities note that the situation is worsened by careless practices, including building owners directly connecting their drains to sewer lines. Such connections overwhelm the system, increase the likelihood of overflow, and exacerbate contamination risks.
