Understanding the dynamics of high and low spring flow: a key to managing the water resources in a small urbanized hillslope of Lesser Himalaya, India

Water scarcity is becoming a major problem in High Mountain Basins of Indian Himalaya. Access to fresh water becomes a core concern for every dweller in the summer season all across the Indian Himalayan Region. This paper presents an assessment of two low yielding perennial springs in one of the urban center located in the very steep mountain slopes of Lesser Himalaya. Spring hydrographs were analyzed to investigate the variability and availability of spring flow in three seasons. Dynamic spring flow volume in storage and time at which the flow may cease were also assessed, as they play a crucial role for planning short-term measures. The linear model using the exponential decay equation is found to be sufficiently accurate to model the recession characteristics of spring outflow from the hardrock aquifers for winter season, as the main contribution comes from baseflow with delayed interflow, which is slow diffuse flow in nature. The present study examines the findings from 1 year of spring outflow and rainfall when deficient monsoonal rainfall (moderate drought) is recorded in major parts of the country. The data can play a significant role in estimating dependable minimum water availability from the spring outflow and planning for appropriate capacity of low to medium storage structure for conserving the excess water which goes unutilized even during the high scarcity period. The analysis of duration curve suggests, more focus should be given for conserving the surplus water available during the monsoon through appropriate storage structures, which can be used during the leanest month.