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Water
Requirement and Sources of Water in Delhi
Delhi is experiencing increasing pressure to meet demand for
its water resources. Growing urbanization, improvements in living
standards, exploding population are just some of the contributing
factors. The population of Delhi is expected to cross 15 million by
the end of 2002. The city, at the moment, requires 3,324 million liters
of water a day (MLD) while what it gets stands closer to 2,034 MLD.
Average water consumption in Delhi is estimated at being 240 liters
per capita per day (lpcd), the highest in the country. The large-scale
extraction of groundwater is a result of this widening gap between
the demand and supply of water. And still worse, serious doubts are
also being raised about both the quality and quantity of groundwater.
Physiography
The Union Territory of Delhi consists of flat and level plains interrupted
by cluster of sand dunes and a long continuous chain of rocky ridges.
The sand dunes are of varying dimensions and in general trend northeast
- southwest. The crests of the dunes generally lie between 6 and 15
metres above the surrounding plains. They are more or less fixed in
this area and support vegetation. It appears that they are of longitudinal
type and are oriented parallel to the prevailing wind directions.
Drainage
The Yamuna river flowing in a southerly direction in the eastern part
of the Union Territory of Delhi is the only perennial river in the
area. Eastern and western Yamuna canals and Agra canal are the three
major canals which originate from the Jamuna river with Bawana, Rajpur
and Lampur distributaries. Auchandi, Budhanpur, Sultanpur Mundka,
Mongolpur, Nahari, Dhansa and Surkhpur are some of important minors.
The Agra canal originates from Okhla, about 12 km. South of Delhi.
Delhi receives its water from
3 sources:
A. Surface Water:86% of Delhi's total water supply comes from surface water, namely the
Yamuna River, which equals 4.6% of this resource through interstate
agreements.
B. Sub-surface water: Ranney wells and tubewells.
This source, which is met through rainfall (approx. 611.8 mm in 27
rainy days), and unutilized rainwater runoff, is 193 MCM (million
cubic meters).
C. Graduated Resources: It is estimated at 292 MCM, however current withdrawal equals 312 MCM.
Salinity and over exploitation has contributed to depletion and drastically
effected the availability of water in different parts of the city.
However, according to a report released by the Central Ground Water
Board (GCWB), Delhi's ground-water level has gone down by about eight
meters in the last 20 years at the rate of about a foot a year.
Apart from groundwater, Delhi
gets its water from the Ganga Canal, the western Yamuna canal, the
Bhakra canal and the Yamuna.
Delhi’s water and wastewater
management is controlled by the Delhi Jal Board (DJB), which has signed
the contract with Suez Degremont. With the demand-supply gap projections
for water set to increase in the next ten years, DJB have identified
new raw water sources including Tehri, Renukal, Kishau Lahawar dams.
Plans also center on the construction of new and existing sewage treatment
plants (STPs), which will enable an increase in treatment capacity.
Rainwater harvesting is another option that DJB is considering.
Even though Delhi is one of the first Indian cities to have
paid attention to city planning with the first master development
plan of 1962, the infrastructure for public utilities is proving to
be inadequate, especially under the burden of growing population.
Delhi has total area of 1486 sq kms out of which fully developed
urban areas is 525 sq kms. With over 14 million inhabitants, the city
is bursting at its seams. Population of Delhi is expected to reach
17.5 million by the end of the 10th Five year plan. Situated
on the banks of the river Yamuna, the city is mainly supplied by surface
water from the Yamuna, Ravi beas water ( Bhakra storage) and the Ganga
water. The water availability from surface water sources, viz. Yamuna,
Ganga and Bhakra systems is approximately 1150 MCM ( million cubic
metre), and of this 60
% is available from Yamuna river.Total groundwater availability is
of the order of 290 MCM per year. Delhi receives a total average rainfall
of around 600 mm per year, of which 80 % is received in three months
( July – September).
Water Source
With the present population, the current potable water requirement
is Delhi is 828 Million Gallons per day ( MGD) ; expected to rise
to 1050 MGD by end of the 10th Five year plan. The Delhi
Jal Board is presently supplying about 660 MGD of potable water from
its existing installations (which includes 81 MG ground water).
Water
resources of Delhi Jal Board
|
S.No
|
Source |
Quanitity(MGD) |
|
1
|
Yamuna |
210 |
|
2
|
Ganga |
100 |
|
3
|
Bhakrastorage
Sub total(surface water) |
240
550 |
|
4
|
Ranney
wells/ Tube wells |
81 |
|
5
|
Total |
631 |
Source: Economic survey of Delhi, 2001-02.
The source available
is not sufficient to meet the demand and as such there is a shortfall
of 168 MGD per day of water.
As per the “Economic Agenda for Delhi
– a proposed Blueprint”, prepared by the Confederation of Indian
Industry in association with the Rajiv Gandhi Foundation, using
the DJB norms on water supply, there will be a huge supply gap by
the year 2011. The demand is expected to be 1600 million gallons
a day (MGD) versus a proposed treatment capacity of 990 MGD. Owing
to this situation of escalating population without a commensurate
increase in the availability of raw water, the ground water in Delhi
has been over exploited. This has disturbed the hydrological balance
leading to decline in the productivity of wells, increasing pumping
costs and more energy requirement.
The groundwater table is Delhi has depleted to 20 –30 metres in
various areas across the city. Compared to a level of 30 – 40 feet
at the time of Independence, the water table has dropped to 350
feet at certain places. It is said to be falling at 10 feet per
year on an average. Groundwater levels have depleted by 2 – 6m in
Alipur and Kanjhwla blocks, 10m ins the Najafgarh block, and about
20 m in Mehrauli block.
The quality of underground water is also deteriorating and in several
places it has been found to tbe unfit for human consumption.
Almost 46 % of the population still does not have access to piped
carriage systems. In addition there is the issue of unequal supply
– 29 liters per capita per day ( lpcd) of water supply in some areas,
compared to 509 lpcd in cantonment area.
The problems are compounded by an inadequate
sewer system and blocked drains.
But there is a disparity in the cost
of production and operations of water supply and water tariffs being
charged. Currently only 35 % of the cost of proper operation, maintenance
and upkeep of the water supply and sewerage system are collected
through water tariffs.
The revenue collected is hardly
able to meet the cost of electricity bill and other requirement
of chemicals like chlorine etc. The cost recovery is only 60 % of
the production cost of water . Rest 40 % is Non- Revenue water.
A
recent report reveals that people in Mehrauli and Narela receive
only 29 and 31 liters per person per day respectively, those in
the Cantonment Board get 509 liters and Lutyen's Delhi 462 liters,
The Karol Bagh zone receives 337 liters per person per day. It is
also estimated that unless the depleted water table in Mehrauli
is maintained or replenished, Mehrauli will experience desertification
within the next ten years.
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