Groundwater, found beneath the Earth’s surface, is stored in tiny spaces within soil, sand, and rock formations known as aquifers. It originates from rain and other surface water that seeps down through the soil, filling these underground spaces. Groundwater is a critical resource, contributing to drinking water supply, agriculture, and river flow during dry periods.
Protecting groundwater from contamination is essential, as polluted groundwater is difficult and costly to clean. Proper management and monitoring are vital to ensure this valuable resource remains safe and sustainable for future use. Groundwater resources are often not visible, making them vulnerable. Pabitra et al. (2024) reported that groundwater resources in the Himalayas including Bhutan face challenges from climate change, increased variability in rainfall patterns, overuse, and poor management. These factors lead to depletion, affecting water availability for communities and agriculture, and exacerbating water scarcity issues.
In Bhutan, groundwater could be increasingly threatened by various pollutants from agrochemicals, leachates from dumpsites, and chemicals from stormwater runoff. Additionally, hydrocarbon contaminants from automotive workshops (e.g. Olakha workshops) and toxic chemicals from industries like dry-cleaning services pose significant risks. The potential impact of hormones and synthetic chemicals from pharmaceuticals on groundwater also currently remains largely unknown. Agencies responsible for water management in Bhutan currently have limited scope for such management due to other priority issues.
A brief review of the scientific literature and professional experiences of a group of water researchers from Bhutan revealed few scientific investigations on groundwater management in Bhutan. The Asian Development Bank (ADB) in 2016, while assisting the Royal Government of Bhutan in formulating plans for a water-secure future, mentioned that “Groundwater and reservoirs contribute to the country’s overall water resource. Although groundwater resources are believed to be limited in the rugged mountain areas of Bhutan, the wider and flatter valleys of Paro, Punakha, Thimphu, Wangdue, and areas bordering the plains of India may have significant groundwater reserves.” Such observations clearly show limited scientific evidence for the formulation of groundwater management policy for Bhutan.
A group of Bhutanese researchers (Thanpa et al., 2022) conducted a study on the groundwater potential of the Phuentsholing area. They identified high groundwater potential zones in Damdhara, Kabraytar Valley, and Toorsa. According to the researchers, the validation of groundwater at these sites was supported by the existence of spring water and rich vegetation even during dry seasons. Geological formations like lineaments and perennial streams were reported as positive indicators of groundwater at those study sites. The research findings indicated that Phuentsholing Thromde has an opportunity to extract groundwater from these high-potential areas to meet the increasing demand for drinking water. However, recommendations on the use of groundwater as a source of potable water need to consider water quality, as groundwater treatment is often not cost-effective. The main takeaway from this study is whether similar studies can be replicated across the country, starting with areas that could potentially hold groundwater, such as the southern foothills, including Gelephu Mindfulness City (GMC).
Thapa et al. (2022) also reported significant environmental challenges regarding groundwater resources in the Phuentsholing area: “There are 11 bore wells at the YDF site, out of which two have stopped yielding. The drilling of bore wells was carried out without any scientific studies, and details about the bore wells were missing.” Bore drilling and development are costly, and the lack of geo-technical data on bore development leaves a significant gap in informing the management of the bore and water quality in the long run.
The Bhutan Water Policy (2007) mentions, “Alternative sources like groundwater and rainwater harvesting shall be explored in areas with water shortage.” The policy indicates that groundwater is a separate entity from other water resources, while in reality groundwater resources are interlinked with other water resources. A recent study by Tshewang et al. (2025) further provides evidence of linkage between all water resources using isotopic analysis in Yude Ri and Dungju Ri catchments in eastern Bhutan, where shallow groundwater was reported to contribute to spring flow. The research results also show that spring flow in the catchment is strongly sensitive to any changes in precipitation and precipitation patterns in the future.
Groundwater variability is evident given the diverse ecological and geophysical characteristics across Bhutan. However, currently, there is insufficient data to make informed decisions. For example, the underground linkage between the ponds, dams, and rivers in the GMC landscape needs to be ascertained for sustainable management of the water resources in a critical project area for Bhutan. Increased groundwater infiltration due to forests in Bhutan may benefit neighbouring countries through the extraction of groundwater across international borders. On the other hand, over-extraction of groundwater in Phuentsholing and GMC could ‘pull’ contaminants from groundwater across the border. Therefore, as a group of water professionals, we propose the following step-wise options for groundwater resources management within the scope of financial and human resources of the water management agencies and local governments.
Revisiting Policy Framework Develop comprehensive guidelines for groundwater management. The policy should address groundwater and surface water as an interlinked system, rather than treating them as separate entities. The policy framework needs to provide overall legal requirements to manage water resources effectively, based on accurate and up-to-date scientific data.
Groundwater Mapping and Legal Protection of Recharge Areas
Prioritise creating detailed maps of groundwater resources to identify potential vulnerabilities and inform targeted interventions. A centrally located database showing bore locations and a repository of all bore details is essential. Requiring a permit for drilling and the submission of drilling data should be mandatory for bore development and management. This permit should also stipulate quarterly or annual water level gauging and water quality testing based on the risk at the location. Furthermore, recharge areas for public drinking water supply should be legally designated and protected from contamination.
Build Evidence Strategically
Gather site-specific hydrogeological data to better understand aquifer characteristics and the feasibility of natural attenuation processes. Long-term trends in water quality and groundwater levels are essential for making informed decisions. Start with tier 1 resource assessment tools and tier 1 risk assessment tools, then build on them to improve accuracy and reliability. For example, lead water agencies could begin with studies like Thapa et al. (2024), where Seismic Refraction Tomography (SRT) and Geographic Information System (GIS) were used to delineate potential groundwater zones. Such an approach could help identify and map groundwater resources and highlight critical areas needing protection. Currently, the potential distribution of groundwater resources across Bhutan is largely unknown. For example, Thongley (2023) found that only less than two percent of the study area in Chang Gewog, Thimphu, had very high groundwater potential. Therefore, establishing preliminary resource mapping is a crucial first step.
Geotechnical Data Repository and Groundwater Monitoring Network
Establish a centralized repository for geo-technical data to inform drilling decisions and prevent groundwater pollution. Implement a robust groundwater monitoring network, similar to the surface water monitoring system, to track contaminant levels and evaluate remediation efforts. Explore avenues to integrate this with existing environmental data collection. For example, install sensors in bores at each weather station or gather all water-related properties at national forest inventory sampling sites across the country.
Prioritising Risk Areas
Identify key activities and industries contributing to groundwater contamination, including landfills, gas stations, dry cleaning services, automotive workshops, and industrial sites. National agencies should provide overall standard requirements for reporting and investigations, including the use of a Conceptual Site Model (CSM). A CSM is an essential tool in environmental management, offering a comprehensive written and visual representation of the potential linkages between contaminated sites and the environmental receptors they may impact. It identifies the types and sources of contaminants, outlines the pathways through which these contaminants can travel, and assesses the risks posed to human health and the environment. By highlighting critical areas that need attention, a CSM informs the development of effective remediation strategies. Additionally, it serves as a valuable communication tool among stakeholders, ensuring a clear understanding of site conditions and associated risks.
The article is published based observations by a group of water researchers from Bhutan (www.waterresearchbhutan.org)