Water mismanagement in India causes great havoc. In many areas that receive abundant monsoonal rainfall, adequate water for domestic uses in other seasons is not available. At the same time, the intense urbanization in the country presents an opportunity for landscape architects and urban designers to actively address water security. This study discusses water use as a determining metric for undisturbed sites, or 'greenfield' developments, that have an abundance of water during the monsoons and water scarcity in other seasons. The article uses projective design for a greenfield city-Naya Raipur-in central India, to argue for rainfall metrics to calculate population density and water harvesting bylaws, in order to meet all per capita domestic water requirements. The proposed use of a mandatory per capita water harvesting area is an easily applicable solution for water scarcity, which can provide autonomy to households for water management and control the density of a city based on the availability of water in the region.