Groundwater Mapping

Government initiatives for better resource management

The government is radically changing the way it utilises and monitors the available freshwater resources. The intention is to reduce groundwater exploitation and optimise freshwater utilisation through the introduction of a countrywide water quantity and quality measuring system.

In the past, the government has implemented a number of projects such as the Hydrology Project Phases I and II, and the National Project on Aquifer Management to monitor the available freshwater resources on a real-time basis. However, the majority of these projects failed to achieve the desired results due to the lack of countrywide coverage.

The recently launched National Hydrology Project (NHP) is a significant departure from the past and aims to ensure prudent water management and sustainable consumption of groundwater. This is a significant move at a time when the country is reeling under a severe water crisis. India has faced three droughts between 2000 and 2012, and is reportedly the largest consumer of groundwater in the world, consuming about 61 per cent of its annual replenishable quantity of water.

Hydrology Projects I and II

The initial attempts of the government to establish a comprehensive database for the hydrological system was made with the Hydrology Project Phase I (HP I), implemented during the period 1995-2003. Under this project, a hydrological information system was developed in nine states – Andhra Pradesh, Chhattisgarh, Gujarat, Karnataka, Kerala, Madhya Pradesh, Maharashtra, Odisha and Tamil Nadu. About 916 river gauge stations, 7,889 observation wells and 436 hydro-meteorological stations were established for collecting data on the qualitative and quantitative aspects of surface water and groundwater. A number of advanced software solutions were deployed to create a comprehensive database. These included the surface water data entry system, hydrological modelling system, water information system for data online management of surface water, groundwater data entry software, and groundwater estimation and management system.

HP II was launched in 2005 and completed in 2014. It was implemented in 13 states with similar objectives. A unique feature of HP II was a notable shift from manual data collection to real-time data analysis. However, the projects focused more on real-time monitoring of floods than on groundwater management.

National project on aquifer management

In 2012, the central government launched the National Project on Aquifer Management, a dedicated groundwater mapping project, to monitor the quality and quantity of groundwater resources on a real-time basis. Although groundwater mapping was being carried out under HP I and HP II by the Central Ground Water Board (CGWB) and state groundwater and drinking water supply departments on a regular basis, the information collected was not sufficient for comprehensive groundwater management. Subsequently, the National Project on Aquifer Management was launched with the aim of identifying and mapping aquifers at the micro level.

This project was launched on a pilot basis in six cities – Patna (Bihar), Duasa and Jaisalmer (Rajasthan), Nagpur (Maharashtra), Tumkur (Karnataka) and Cuddalore (Tamil Nadu). The target was to quantify the available groundwater resources, analyse the existing consumption, determine future demand and make institutional arrangements for participatory management. The data collected by various agencies was compiled and analysed for identifying gaps, particularly in subsurface information and aquifer geometry parameters, draught, water level and water quality. For this purpose, the CGWB created a comprehensive database of the six pilot areas with information on hydrology, geomorphology, geology, hydrogeology, borehole drilling, geophysical findings, hydrochemistry, groundwater use and contamination, and vulnerability to groundwater quantity and quality.

Next, all aquifers up to 200 metre depth in hard rocks and up to 300 metre in sedimentary areas were mapped and the aquifer geometry was redefined to the scale of 1:50,000 and 1:10,000. A series of studies were conducted in the pilot areas to prepare an inventory of the major aquifers in the regions. The authorities also studied the nature and period for which water from these aquifers was consumed. Further, the hydrostatic heads of the major aquifers were studied on a monthly basis through shallow dug well monitoring stations, piezometers, etc. The wells were fitted with pressure transducers to record changes in the pressure heads of the piezometers on a continuous basis. The variations in the phreatic and piezometric heads were analysed to understand the groundwater flow pattern along and across the aquifer units.

Post the collection of field-level data, digital maps depicting the groundwater level were prepared in collaboration with the information compiled by the National Remote Sensing Centre. For this purpose, three different groundwater mapping techniques – airborne, ground based and logging of borewells – were deployed.  The information obtained from the study was integrated with the results of geophysical and hydrochemical studies. The information derived is essential for delineating areas of potential and non-potential aquifer zones and comprehensive modelling of the entire aquifer system.

In the pilot locations, the project has aided the authorities in identifying areas suitable for artificial recharge, potential aquifers and freshwater aquifers, and studying the present and future demand as well as forecasting the future groundwater conditions. Furthermore, the project has assisted in identifying unknown contamination sources and mapping fractured aquifers, among others.

Recent initiatives – NHP, 2016

NHP aims at setting up a comprehensive system for reliable water resources data acquisition, storage, collation and management. It covers the entire country as opposed to the previous hydrology projects (Phases I and II), which covered only 13 states.

The project was approved by the central government in April 2016, with a total outlay of Rs 36.79 billion. Of the total outlay, Rs 36.4 billion has been earmarked for the NHP, while Rs 397 million has been set aside for setting up an independent organisation, the National Water Information Centre (NWIC), under the aegis of the Ministry of Water Resources, River Development and Ganga Rejuvenation. The World Bank will provide about 50 per cent of the total project cost, that is, Rs 18.4 billion, as a loan while the remaining amount will come in the form of central budgetary assistance.

Apart from building a comprehensive hydrological database, the project will facilitate water resource management and ensure equitable use of water through real-time flood forecasting and monitoring of reservoir operations and groundwater position. It also aims to facilitate integrated water resource management through the collation and management of hydrometeorological data on a real-time basis. Also, the NHP seeks to build the capacity of state and central organisations for enhanced water resource management. This will be enabled through the deployment of information systems and the adoption of state-of-the-art technologies like remote sensing. The overall aim of the project is to help in water resource assessment through scientific data collection and prioritise water allocation and use.

The successful implementation of the project is expected to result in better data storage, analysis and dissemination through the NWIC. The lead time in flood forecasting is expected to be increased from one day to at least three days. Further, the project will help in the accurate assessment of surface and groundwater resources in a river basin. It will also assist the authorities in the allocation and prioritisation of fast-depleting water resources.

Conclusion

Although a number of initiatives are being taken to solve the water crisis, India requires a long-term solution for water resource management. These projects, through real-time monitoring of water resources will, in the future, equip the authorities to take remedial measures.

Going forward, the availability of information will equip urban local bodies to educate domestic, industrial and commercial consumers on the state of freshwater resources. It will also help them in planning, developing and ensuring the optimum use of these resources. That said, the impact of the project will depend on the government’s ability to effectively use the data collected for managing water crises in the future.

 

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