The global warming and subsequent climate change has seriously threatened the glaciers of the Hindukush Karakoram Himalaya (HKH) region. These glaciers provide water to more than 60% people of the 11 countries, including Pakistan. The capital city of Pakistan has witnessed unprecedented urbanisation, population increase, development of new townships and associated economic activities. These challenges, together with climate change, have created severe pressure on the water resources of the city. In this mixed mode research, including questionnaire survey of 20 questions was distributed among the residents of the city online through Google Form. The questions were related to the expected impact of climate change on the availability of water, measures for conservation of water etc. About 205 residents from various parts of the city with different demographic backgrounds responded. This was followed by Focus Group Discussions (FDGs) of the experts and the major challenges to the urban water security of Islamabad with special reference to climate change have been assessed. The research has revealed that the water resources of the city are highly unsustainable. The residents have high concerns about the availability and quality of water. The results have shown that there is a number of governance issues in water distribution systems of the city. There are no organized water conservation strategies employed by City Government. The lack of institutional and policy framework has further complicated the situation. Residents seem willing for metering of water for its conservation. Recommendations have been made to municipal authorities for rational water resource management of the city.