Bihar Chief Minister Nitish Kumar will launch the Har Ghar Gangajal project in Rajgir and Gaya over Sunday and Monday, a unique and ambitious initiative to provide Ganga water on tap in parched areas of the state that do not lie along the course of the river.
The scheme will harvest the excess water in the Ganga during the monsoon flooding season, to be treated, stored, and piped to Rajgir, Gaya, and Bodhgaya, regions that have for long depended on tankers of drinking water from adjoining districts to see them through the hot, dry season.
Har Ghar Gangajal is part of the Bihar government’s Jal, Jeevan, Hariyali scheme. In the Rs 4,000-crore first phase of the project — which has been completed and will be launched by the Chief Minister — giant pumps will lift Ganga water from Hathidah near Mokama and supply it to about 7.5 lakh homes in the state’s main tourism destinations of Rajgir, Bodhgaya, and Gaya.
The water will be stored in reservoirs in Rajgir and Gaya before being channelled to three treatment-and-purification plants, from where it will be supplied to the public. The water will travel more than 150 km through pipes from Hathidah, and will use a network of existing, renovated, and new connections to reach every beneficiary household.
According to estimates made by the government, the scheme will provide every individual beneficiary with 135 litres — about two large buckets — of Ganga water every day for drinking and domestic use. The scheme is currently limited to the urban areas of Rajgir, Gaya, and Bodhgaya. During the second phase of the project, which is expected to be launched some time next year, Ganga water will be taken to Nawada.
The area around Rajgir (in Nalanda district), which was the nucleus of the ancient kingdom of Magadh and is associated with the founders of both Buddhism and Jainism, is rocky and water-deficient. Over the years, unplanned and indiscriminate use of groundwater has depleted subterranean reservoirs, lowered the water table, and affected the quality of the water in Gaya and Rajgir.
The bulk of the urban water supply continues to be through tube wells. A study by the Bihar Public Health Engineering Department (PHED) showed the average groundwater level in Gaya district had plunged from 30.30 feet in July 2021 to 41.50 feet in July 2022. Data from the Central Ground Water Board’s Year Book for Bihar show the water table in Gaya and Rajgir fell by between 2 and 4 metres between 2014-15 and 2020-21.
Handpumps have been going dry at many places in the region. The district administrations of Nalanda and Gaya have been arranging for water tankers to supply drinking water in the town areas as the scarcity becomes acute in the summer. This is a short-term and insufficient measure, and there is an urgent need to shift to a more sustainable and reliable source of water.
The government expects the Har Ghar Gangajal scheme to also help alleviate distress from the annual flooding of the banks of the Ganga. Over the years, heavy silting in the riverbed — affecting especially Mokama, Hathidah, Barh, and Lakhisarai — and the release of water from dams upstream in Nepal have resulted in the Ganga spilling over even when the monsoon rainfall over Bihar has not been exceptionally heavy. It is expected that the diversion of Ganga water during the monsoon season will help to reduce the impact of flooding along the banks of the river.
The government has assured that the water for the scheme would be lifted only during the four months of the monsoon when the Ganga has excess water; therefore, the diversion will not lead to depletion of the river, disturbance in its natural flow, or potential changes in its course. The government plans to build 13 more reservoirs in Gaya and Rajgir to store diverted floodwaters in the coming years.
The project has been described as a “lift-store-tame-treat-supply” system. Hyderabad-based Megha Engineering & Infrastructures Limited (MEIL) has been working on the project since 2019, employing about 2,200 people and high-end technology. A 447-metre approach channel has been constructed in Hathidah on the right bank of the Ganga near the Rajendra Bridge, through which water is taken to an intake-well-cum-pumphouse, which is powered by a dedicated electricity substation with a 7500 KVA transformer, and two smaller 250 KVA transformers. State-of-the-art online filters have been installed near the intake well to ensure silt-free water enters the pump and pipeline, and there is no erosion in the riverbed.
The 151-km pipeline network will use a railway overbridge and four bridges. A water treatment plant with a capacity of 186.5 million litres per day (MLD) at Manpur in Gaya will supply to Gaya and Bodh Gaya. The three storage reservoirs are at Tetar, Rajgir, and Gaya with live capacities of 18.633 million cubic metres (MCM), 9.915 MCM, and 0.938 MCM respectively. Besides Manpur, a smaller water treatment plant of capacity 24 MLD has been built in Rajgir.