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| https://en.wikipedia.org/wiki/Bisalpur_Dam#/media/File:Bisalpur_Dam.jpg |
A tremendous increase of human population has taken place
over the last century leading to a water crisis in both urban and rural
habitations. The present note addresses this issue. A special reference is made
to Jaipur city in Northwestern India but much of the note has value for cities
elsewhere too. We shall begin with some essential fundamentals about water and
then suggest immediate short-term and long-term solutions to the water crisis.
Fundamentals of Water Use
- Along with light and air, water is the basis for life. Poor water quality and inadequate availability of water severely compromises quality of life and living. Therefore, it must be the top most priority for any society and its government.
- There is no shortage of water on the planet for all life that dwells on it. What may however lack is its proper management and distribution.
- Those who talk of water conservation as a means of water management must note that water cannot be destroyed. Its use only changes its condition, form and location on the planet.
Sources of Water
Humans derive their water for use through surface (such as
rivers and lakes) and sub-soil water. With increasing population, pollution of
surface water has increased and depending upon where it is taken from, it may
require considerable treatment before becoming suitable for use. Sub- soil water
is usually purer and may require none or only minimal treatment for use. With advent of
solar technologies pumping of water has become an attractive and economical
option. An earlier note by the author had suggested that solar pumps do not
require battery storage and therefore are economical. Since that note in 2012 (see
here), this pumping method has become widespread, especially for agricultural
use.
It must be noted that just like surface water, sub-soil
water at any given location is not an unlimited supply. Drawing it excessively
from any location depletes it from that location. In order to make its supply
sustainable, there is a need to create surface ponds, streams and lakes to
collect rainwater or recycled water. It then seeps into the ground increasing
the water table. The slow process of filtration through ground purifies water.
On the other hand, if surface water is directly sent into the ground through
deep bores, a method that some modern harvesters promoted in past, it carries
with it surface pollution and ruins quality of sub-soil water. The proper way
to harvest rainwater is to collect it in surface ponds, lakes, streams and dams.
It is true that some surface collection is lost by evaporation but this is not
a total loss since much of it returns to land as rain.
Jaipur Crisis
Some years ago, in 2012, noting that Jaipur city, due to its
expansion, is facing a water crisis this author made suggestions (see
here) on similar lines as in the previous section. It seems as a result of
that the Rajasthan government launched a project to revive a defunct river
(Drvyavati) with the help of rain and recycled water as well as more projects
in rural areas spread across the state. The project is not yet complete. It
will help increase ground water level but it shall be insufficient for needs of
the city even after completion.
The second source of water in Jaipur is water brought in by
a pipeline from the distant dam of Bisalpur. The collection of this water
depends on the quantity of water collected in monsoons as well as declining
conditions of its catchments areas. During the monsoons of 2018 collection was
insufficient and Jaipur city is facing a water crisis. The city is trying to
alleviate the crisis by reviving old bore wells around the city. However this
is an incomplete solution. A better solution is proposed next
Short Term Solution to Jaipur Crisis
While the city of Jaipur is trying to overcome its water
shortage by digging new bore wells in the city to extract ground water, a simpler and far
more effective solution is to dig these bore wells near the Bisalpur Dam and
add that water to the existing pipeline to make up the deficit. Below a certain
level, the water of Bisalpur dam is muddy/turbid and not suitable for supply.
However, the ground water around the dam has a high water table and is of good
quality and is a far more sustainable source. The pipeline and pumps to convey
it to Jaipur already exist.
Usually it makes sense to pump out water from the ground nearest to the location where it is needed. However when a distant location has a far more abundant supply of ground water and the infrastructure already exists (pipeline and pumps) to convey it then it makes far more sense to draw the water from that distant location. It is also often the case that ground water away from urban locations is of a better quality.Because of its low level, Bisalpur dam is currently supplying water at a reduced rate to Jaipur city. The recommendation of this note, by adding ground water to the dam water, can not only restore previous level of supply but also exceed it. The proposal can be implemented rapidly within weeks, not necessarily months.
When extracting ground water from around the periphery of
lakes and dams, the most suitable points with the highest water tables are the
best selections.
Long-Term Solutions
The longer-term solutions to Jaipur water crisis as well as
any other city in a similar situation are two,
- Creating more lakes and reservoirs around the city to store rain water as well as treated recycled water, reviving old reservoirs such as Ramgarh near Jaipur with new channels to bring in water, and setting up bore wells adjacent to them to extract ground water for supply
- Increasing tree cover in city and increasing forests around the city in attempts to increase rainfall. Encouraging farmers to take up horticulture through subsidized assistance on a part of their farmlands also increases tree cover. A fenced or water moat bounded tree area is also excellent for free range poultry and cows as well as bee keeping while the moat serves blue water farming. Studies indicate (see here) that forests create their own rains.
- There is a plan (see here) to link a distant Brahmani river to Bisalpur but this plan is still some years away. In the meantime, the solutions as proposed in this note, if implemented may provide interim relief.
NOTE
A general note useful for all in any country of the world about urban water supply as FAQs (Frequently asked questions) can be found in this blog at:
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