There is growing evidence that monsoon patterns are changing in the Himalayan region, which could potentially result in loss and damage for local farmers. To understand how farmers adapt to changes in water availability, we conducted a study in Punakha district, Bhutan, using qualitative and quantitative research tools. According to 91% of 273 respondents, water availability for rice irrigation has been decreasing over the last 20 years due to changing rainfall. Most of them have taken measures in response. They may, for example, invest in the maintenance of irrigation channels, develop or modify water-sharing mechanisms, or shift to crops that need less water than rice. Of these farmers, however, 88% indicate that their adaptation measures are insufficient. Moreover, they come with extra costs. We argue that these costs should not only be conceived in monetary terms, but also in terms of time investment, social-cohesion and livelihood security.