Ground-Breaking Science
Confirms Traditional Knowledge in
India
June 2007
The Wakal River originates in a remote mountainous region in the southern part of the State
of Rajasthan, India and is the source of the larger Sabarmati River Basin, which has the
lowest per capita water availability of all river basins in India. The Wakal River Basin has a
tropical monsoon climate with a mere average annual rainfall of 650 mm occurring almost
entirely during a 3-4 months period from late June-September. Due to the extreme
seasonal variability of rainfall, there are no perennial rivers in the State. In light of its
sparse surface water supplies, Rajasthan relies on groundwater for 90% of its drinking
water supply and 60% of its water for irrigation. This heavy dependence on groundwater,
coupled with changing climate and growing levels of water consumption, is leading to
increasing seasonal variability and steady declines in groundwater levels, posing a problem
of access to reliable water supplies for many of Rajasthan’s rural inhabitants.
In recent decades, rainwater harvesting (RWH) has been promoted as a solution to the
overexploitation of the Rajasthan’s groundwater resources. Rainwater harvesting is defined
as the collection and storage of rainwater in surface or sub-surface reservoirs as a means to
reduce the amount of water lost to storm runoff and evaporation. Archeological evidence
reveals that indigenous civilizations in India have utilized RWH activities to sustain
agriculture and general water supply for the past 2,000 years. An important objective of
many RWH techniques is to artificially recharge groundwater. Artificial recharge is a process
of augmenting a groundwater reservoir at a rate that exceeds natural conditions of
replenishment.
In light of increased pressure on the groundwater resources, a resurgence of traditional
RWH activities in India has occurred in recent decades, with Rajasthan acting as a cradle of
this rural water management revival. Significant investments have been made to promote
RWH activities among government, non-government, and private sectors, with a major
focus on the artificial recharge potential of RWH. Despite the movement of recent RWH
efforts in Rajasthan, many RWH structures are built without a clear understanding of their
impact on local groundwater. This knowledge gap is the result of a lack of systematic
investigations of these traditional water management techniques. With GLOWS support, FIU
master’s student John Stiefel worked with a team of Indian and U.S. scientists to investigate
the effectiveness of RWH structures for groundwater recharge in the Wakal River Basin.
Over the course of his master’s degree, John designed and carried out a detailed physical
and geochemical investigation to determine the impact of RWH structures on localized
groundwater supplies in the basin. This study focused on quantifying the proportion of
artificially recharged groundwater in nearby rural wells, as well as examining potential
effects of artificial recharge on the groundwater quality in these wells.
The results of this study give valuable insight into the artificial recharge potential of RWH in
the Wakal River Basin. It was determined that many of the wells located in the study area
received additional groundwater as a result of artificial recharge from the RWH structures.
Furthermore, it was revealed that the groundwater quality in these wells was improved with
respect to many important drinking water quality parameters, compared to wells that were
unaffected by RWH structures. The results of this study provide a quantitative description of
the impact of artificial recharge induced by RWH on water supply in rural wells of the Wakal
River Basin, India. This knowledge adds important understanding to current water
management practices and can be used to guide future water management planning in the
basin.