Determining the recharge area of ground water can greatly enhance our understanding and management of land use, especially in mountainous urban areas such as Kathmandu. Analyzing the stable isotopic composition of precipitation, unconfined aquifers, and deep aquifers, two specific recharge areas were noticed, contrary to previous research indicating only one recharge area. The other focus of the study was to see the effect of elevation on the stable isotopes of precipitation. Precipitation samples were collected in nine different elevations around the Kathmandu basin. A multiple regression model showed that delta values in precipitation were correlated with elevation, latitude and time of year (R² = 0.41).