In India’s populous capital city Delhi, having about 23 million inhabitants
, the demand for water is greater than its supply. According to the city government’s water supply department, namely Delhi Jal Board (DJB), daily water demand
is about 1,150 million gallons per day (mgd), whereas 935 mgd of water is supplied. In the prevailing conditions, many residents of Delhi, particularly those living in informal areas, do not have adequate access to drinking water.
The river Yamuna passes through the eastern parts of Delhi, and water flowing in the Delhi segment of the river is obtained by the city government for treatment and distribution to citizens.
In this article, an attempt is made to describe the different sources from where water is being obtained by DJB for distribution to citizens. Although such information is useful for various purposes, such as for better planning and development of the water sector, it is not properly available in public domain. This article aims to fill the gap in knowledge.
Water bodies on land
Water available in water bodies on land is the most significant source of water for Delhi. This water, usually referred to as surface water, is available in rivers and canals in and around Delhi.
The river Yamuna passes through the eastern parts of Delhi, and water flowing in the Delhi segment of the river is obtained by the city government for treatment and distribution to citizens. The volume of water available in the river varies during the year. During the two to three months of the rainy season (July to September), the water level is high. However, the levels fall significantly during the summer months (April to June) due to high demand by several north Indian states, including Delhi, which utilise Yamuna river water (as per a water sharing agreement) to meet their needs.
It is also noted that the quality of Yamuna river water
is affected by discharge of untreated domestic and industrial wastewater, as well as disposal of garbage. These conditions are prominent particularly at the river front near Delhi’s Kalindi Kunj area.
The low levels of water in the Delhi segment of the Yamuna for most months in a year and the water’s inferior quality are important reasons for Delhi’s dependence on outside surface water sources.
Every year, before the beginning of the winter season, the canal is closed by the UP Irrigation Department for annual maintenance.
The first external source is the upper Ganga canal, which passes through the neighbouring state of Uttar Pradesh (UP). It was built to irrigate land. Some water is also utilised for meeting people’s drinking water needs. This canal originates from the river Ganga at Haridwar in the north Indian state of Uttarakhand and passes through western parts of UP. At Muradnagar in UP, the canal is closest to the eastern boundary of Delhi, where infrastructure has been laid for bringing canal water to Delhi. This water is treated and supplied to the south, east, and northeast areas of Delhi. Every year, before the beginning of the winter season, the canal is closed by the UP Irrigation Department for annual maintenance
(silt cleaning from the canal). The temporary closure disrupts water supply in Delhi.
The second external source lies to the north of Delhi in the neighbouring state of Haryana. This comprises two canals: Western Yamuna Canal (WYC) and Munak Canal (also known as carrier lined channel). WYC originates from the river Yamuna at the Hathnikund barrage in Yamuna Nagar district of Haryana, whereas Munak Canal is an offshoot of WYC that starts at Munak village in Karnal district of Haryana, northwest of Panipat city. Both these canals carry Yamuna river water in a southerly direction, and are important sources of water for Delhi. Munak Canal has several branches and the one terminating at Haiderpur in Delhi is known as the Delhi Sub-branch. In the past, there have been instances
of inadequate water supplied to Delhi by the Haryana government, as well as disposal of garbage in canal water by local communities. In 2016, supply from this canal was disrupted
due to damage caused to canal infrastructure by local protesters who demanded job quotas.
WYC originates from the river Yamuna at the Hathnikund barrage in Yamuna Nagar district of Haryana, whereas Munak Canal is an offshoot of WYC that starts at Munak village in Karnal district of Haryana, northwest of Panipat city.
The third external source is Bhakra storage
, which is situated in the northern mountainous state of Himachal Pradesh. From this storage, the waters of the Ravi and Beas rivers are supplied through a network of canals to several north Indian states/union territories, including Delhi. A link canal has been created to carry water from Bhakra Canal to WYC. After Bhakra storage water reaches Haryana through the canal system, the water is carried forward to Delhi via the WYC and Munak Canal.
Water below the ground
Within the administrative boundaries of Delhi, there isn’t much water available from various sources. The case of the Delhi segment of the Yamuna is described above. The other source is water available below the land surface, usually referred to as ground water. For extracting ground water, tube wells and ranney wells
have been installed by the city government in various parts of Delhi, such as in the Palla floodplain area
in north Delhi near the Yamuna river. Other areas in the city displaying better ground water levels are being explored for extraction of ground water.
The low ground water availability in Delhi is because of various reasons. First, Delhi is situated in a semi-arid region of the country that receives less rain, implying less recharge of ground water. Secondly, Delhi’s hydro-geological profile characterised by alluvial formation and quartzite rock influences ground water occurrence. Finally, over exploitation of ground water
has resulted in its depletion in many parts of the city. The other issue in this regard pertains to the inferior quality of ground water, observed from the presence of toxic metals
beyond permissible limits.
Water from rain
Some amount of water received from rainfall is also tapped. For this purpose, the government has a policy of installing rainwater harvesting (RWH) structures in all its premises/buildings. It has also been made mandatory for citizens to install RWH structures in their properties measuring 100 sq m and above.
For extracting ground water, tube wells and ranney wells have been installed by the city government in various parts of Delhi, such as in the Palla floodplain area in north Delhi near the Yamuna river.
The physical progress shows the establishment of RWH structures
in many government and private buildings, including housing societies, hospitals, schools, colleges, universities, international airport, etc. This method is helping in ground water recharge and use of stored rainwater for non-potable purposes, such as gardening, washing cars, etc. However, the full potential of RWH remains untapped
as many government and private property owners are yet to install the structures. The problem of non-functional structures
is also noted.
Water from used water
The city government has laid down the sewerage network and installed several treatment plants at various locations for reuse of used water, or wastewater/sewage. As per available data
, about 80 percent of the city’s population is covered by the sewerage network, and 70 percent of the wastewater generated is treated.
The treated wastewater is being supplied to the Central Public Works Department, New Delhi Municipal Council, Municipal Corporation of Delhi, and Horticulture Department for non-potable uses.
A review of sources of water for Delhi reveals that the city government relies on multiple external and internal sources to meet its water needs. External sources include the waters of the river Ganga in UP received through upper Ganga canal; river Yamuna in Haryana received through WYC and Munak Canal; and rivers Ravi and Beas in Himachal Pradesh for which the Haryana canals are the carrier system. Within Delhi, water sources are the Delhi segment of the river Yamuna, ground water, rainwater, and wastewater.
It is learnt that over 90 percent of the water is obtained from surface water sources situated in the states of Haryana, Uttar Pradesh, and Himachal Pradesh. Thus, Delhi relies heavily on external sources for meeting its water needs. Further, the city government is experiencing difficulties in maintaining desired ground water levels and its quality, treatment of wastewater, and rainwater harvesting. Early resolution of problems will help in ensuring better supply of water to the citizens.
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