Tales Behind the Tap - 2
Part 1 covered the design aspects of a water supply system. In this part, we take a look at losses and other issues with water supply systems.
Population growth is a fact, and so too is the increasing requirement of water as a result. Local resources have depleted or are no longer sufficient, and water is being increasingly drawn from more and more distant resources. Take the Narmada for example – it is now either the primary source or at least a major source of water for Bhopal, Indore, Vadodara and Ahmedabad – four of the top 20 Indian cities in terms of population (2011 census), in addition to a number of other cities and towns (Jabalpur and Ujjain are marked on the map). High expenditure is involved in extracting water from the Narmada in all these cities due to either topography or distance. Both Bhopal and Indore are located at a straight-line distance of around 60 km from the water extraction locations on the Narmada, with significant and sharp increase in elevation en route due to the hilly terrain just north of the river. These four cities previously used to get water from sources located much closer.
Instances of wasteful use of treated water include use of large amounts of running water for washing a car or the floor around the house, with the water sometimes into the streets. Such activities are often declared illegal during summer times by some urban authorities, and penalties will be charged if such wasteful usage is reported to the authorities.
Thus it is clear that there are several factors involved when it comes to the inefficiencies, losses and revenue generation in a water supply system. Illegal activities or negligent use by people also contribute to these. Judicious use of water, including
avoiding the illegal activities mentioned above, will help in curtailing at
least some part of these losses.
Population growth is a fact, and so too is the increasing requirement of water as a result. Local resources have depleted or are no longer sufficient, and water is being increasingly drawn from more and more distant resources. Take the Narmada for example – it is now either the primary source or at least a major source of water for Bhopal, Indore, Vadodara and Ahmedabad – four of the top 20 Indian cities in terms of population (2011 census), in addition to a number of other cities and towns (Jabalpur and Ujjain are marked on the map). High expenditure is involved in extracting water from the Narmada in all these cities due to either topography or distance. Both Bhopal and Indore are located at a straight-line distance of around 60 km from the water extraction locations on the Narmada, with significant and sharp increase in elevation en route due to the hilly terrain just north of the river. These four cities previously used to get water from sources located much closer.
Other examples of distant sources are
Bengaluru (river Cauvery which is over 60 km from the nearest point on the city
outskirts) and Hyderabad (Nagarjuna Sagar dam which is over 100 km away).
Costs, loss and misuse
The agency providing water is
typically a government-controlled agency. The costs involved in water supply
include factors such as initial one-time costs for setting up the infrastructure (laying and connecting pipes, constructing pump houses and storage tanks etc.), and recurring costs such as maintenance costs, cost of the
energy consumed by the pumps, employee salaries, cost of withdrawing raw water
etc. Electricity bills for water works can easily run into several crores of
rupees per year. Water bills are issued to recover all these costs.
Some percentage of the water is
separately marked for fire fighting use, supply to low-income end users etc.
and the income received from this water is less than the income received from
the remaining water supplied, or occasionally none at all. Water which is
supplied but does not generate any revenue is known as ‘non-revenue water’ or
NRW.
There are many cases where water consumption is not metered and the water bill does not depend on how much water was consumed. Even in case of metered connections, the rates for water are quite low. Consider Mumbai for example - the lowest rate is just above Rs. 5 for ONE THOUSAND LITRES - one thousand litres of water which is fit for drinking directly. It is a combination of a number of factors like inadequate metering infrastructure, low prices and widespread misuse and illegal activities which results in a major loss of revenue. In Bengaluru for example, almost half the water that was supplied was unaccounted for in 2016. The is not only a loss of water and revenue, but also wastage of the significant amounts of energy consumed in pumping the water and the chemicals/materials used for its treatment.
Losses occur due to leakages at
various points in the system, and due to activities such as illegal tappings
from pipes and direct installation of pumps on the line by individual
consumers. Whenever an illegal connection is made on a pipe, it makes it
possible for more water to flow through the system. This leads to a decrease in the pressure of the water at points further
downstream. In severe cases, the water may not be able to reach some areas of
the network due to low pressure. Directly installing a pump on the line with a
view to suck in more water causes low water pressure in the nearby connections
and deprives them of water; even though this activity is also illegal, there are frequent reports of municipal corporations seizing several such pumps
from numerous users.
(Source:https://www.thehindu.com/news/cities/Madurai/138-motor-pumpsets-seized-in-madurai-for-illegal-tapping-of-water/article17681614.ece)
Instances of wasteful use of treated water include use of large amounts of running water for washing a car or the floor around the house, with the water sometimes into the streets. Such activities are often declared illegal during summer times by some urban authorities, and penalties will be charged if such wasteful usage is reported to the authorities.
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