National Hydrology Project

Groundwater mapping for better resource management

The Government of India is radically changing the utilisation and monitoring of available freshwater resources. The intention is to reduce groundwater exploitation and optimise freshwater utilisation through a nationwide 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 freshwater resources on a real-time basis. However, most of these projects failed to achieve the desired results due to the lack of nationwide coverage.

The recently launched National Hydrology Project (NHP) is a significant departure from the past and aims to facilitate prudent water management as well as ensure sustainable consumption of groundwater across the country. The project has been approved at a time when the country is reeling under a severe water crisis. India faced three droughts between 2000 and 2012 and is currently suffering another due to scanty rainfall. Reportedly, India is the largest consumer of groundwater in the world and consumes about 61 per cent more than its annual replenishable quantity.

Hydrology Project Phases I and II

The initial attempt by the government to establish a comprehensive database for the hydrological system was made with the Hydrology Project Phase I (HP I), implemented during 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. In total, 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 both surface water and groundwater. Advanced software such as a surface water data entry system, a hydrological modelling system (HYMOS), a water information system for data on-line management of surface water, groundwater data entry software, and a groundwater estimation and management system were deployed to create a comprehensive database.

HP II (launched in 2005 and completed in 2014) was implemented in 13 states and had objectives similar to HP I. A unique feature of HP II, though, was a notable shift from manual data collection to real-time data analysis. However, these 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 by the Central Ground Water Board (CGWB) and the state groundwater and drinking water supply departments on a regular basis under HP I and II, the information collected was not sufficient for comprehensive groundwater management.

Under the National Project on Aquifer Management, aquifers were identified and mapped 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 aim of the project 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 sub-surface information, 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, as well as vulnerability to groundwater quantity and quality.

Next, all the aquifers up to a 200 metre depth in hard rocks and up to 300 metres in sedimentary areas were mapped and the aquifer geometry was redefined to a scale of 1:50,000 and 1:10,000 respectively. A series of studies were conducted in the pilot areas to prepare an inventory of major aquifers in the regions. The authorities also examined the nature and period of water consumption from these aquifers. Further, the hydrostatic heads of 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 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 field-level data collection, digital maps depicting the groundwater level were prepared in collaboration with the National Remote Sensing Centre using the information compiled by them. 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 so derived is essential for delineating areas of potential and non-potential aquifer zones and for the 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, 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 initiative – National Hydrology Project, 2016

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

The project was approved by the centre 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 as a loan (Rs 18.4 billion), 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 as well as monitoring reservoir operations and the groundwater position. It also aims at facilitating integrated water resource management through the collation and management of hydro-meteorological data on a real-time basis.

Further, the NHP seeks to build the capacity of state and central organisations to undertake  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 final aim of the project is to help in water resource assessment through scientific data collection and to prioritise water allocation and use.

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

Conclusion

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

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 managing  the use of water resources optimally. 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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