Water scarcity is a prime concern in many parts of India. Large amounts of rainwater drain into streams and rivers during the rainy season. Stormwater harvesting is one way to conserve water resources.
Shray Pathak from IIT Roorkee has been involved in geospatial technology-based water management. Recently, he collaborated with researchers from Spain and the United States to come up with a model to evaluate hotspots in Dehradun for stormwater harvesting.
Dehradun district has seventeen towns and more than 700 villages spread over an area covering more than 3000 square kilometres and gets more than 200 centimetres of rainfall per year. Shray Pathak and team took land use, soil and slope maps – all at a 30 metre resolution. Daily rainfall data from the Indian Meteorological Department was available at a resolution of 0.25°.
They used a geographic information system approach, overlaying the maps. Using principal component analysis, the researchers identified eight hotspots for stormwater harvesting, near urban areas that are thirsty for water during summer and winter.
But before initiating a project of collection, storage, treatment or purification of storm water for its eventual reuse, several social, economic and cultural aspects of water use need to be considered. After all, it is people who use the stored water.
So the scientists prepared a questionnaire which included all queries addressing issues related to social, cultural, political, habitat and environmental considerations. They connected the questionnaire to the geographic information system and presented it in a workshop where people with relevant expertise as well as many educated people filled up the questionnaire after assessing the information.
They took responses from all the stakeholders – public health functionaries, environmentalists … They had to consider ten different parameters: public health risk, impact on environment, construction risks, need for recreational activities, community acceptance, need for water reuse, effect on nearby places of cultural or religious heritage, condition of groundwater and effect on nearby habitats. The researchers used the Analytic Hierarchy Process where priorities are given weights to come to consensual decision making.
The web-based geographic information system used for developing the decision-making mechanism made sure that all factors that come in the way of constructing water harvesting structures have been considered before suggesting two sites where stormwater harvesting structures can be built.
According to the scientists, the framework is helpful for the stakeholders and water management professionals. The framework integrates collective planning mechanisms and the resulting planning process goes to the web, says R D Garg, IIT Roorkee.
The web-based platform to interact with civilians and to make informed decisions is a most democratic method, necessary for the successful implementation of such a project, says C S P Ojha, IIT Roorkee.
There is scope for using similar interactive platforms for decision-making in projects involving environmental, political, socioeconomic, religious or cultural issues.
Environ. Manage., 242: 351-361 (2019);