How Rain Water Harvesting can stem Hyderabad’s water crisis
Mayank Ale writes: There is an acute shortage of water in Hyderabad. Today Hyderabad receives water from 4 rivers – Musi, Krishna, Godavari and Manjeera. With 2 of the 4 rivers, Manjeera and Musi, drying up due to over usage, the city is facing acute water shortage and are getting water from farther and farther away.
Water Situation in Hyderabad Today
There is an acute shortage of water in Hyderabad. Today Hyderabad receives water from 4 rivers – Musi, Krishna, Godavari and Manjeera. With 2 of the 4 rivers, Manjeera and Musi, drying up due to over usage we are facing acute water shortage and are getting water from farther and farther away to quench people’s thirst.
Today Hyderabad receives ALL its water either from the distant rivers, or from deep tube wells or from tankers bringing water from outside Hyderabad. In case of a power and petrol crisis, Hyderabad has NO water. The city therefore, will be dead!
Almost every drop of water we use in Hyderabad has an input of energy – either as electricity or petrol/diesel. Most electricity for Hyderabad comes from coal. Thus all the water we use has an embodied energy input from fossil fuels. So when you leave a tap running unnecessarily, you are not only wasting precious water, but also precious fossil fuels and adding to CO2 emissions and adding to global warming.
It is not that Hyderabad is very poor in rainfall. It receives normally 800 mm of rain fall every year. But any heavy shower, exceeding 50 mm, creates a huge problem for the city. There are puddles and water logging in every low lying area of the city. Storm drains run full and accidents occur. Old houses fall down. However what receives maximum attention from the media is traffic jams.
So what is the Water Problem?
Let us see how the problem got created historically.
Human settlements historically have been established near rivers/lakes/areas where water availability was not an issue. The prime principle on which these settlements were established was that people would go to where water is.
A hundred years ago people in Hyderabad got water either from local water tanks also known as Kunta or from community wells known as Baoli. Some people had their own wells. These wells were shallow wells having a depth around 50 feet or so. Those who lived next to the river Musi, used the river.
Then Musi was dammed and two huge tanks/lakes were created – Osman Sagar and Himayat Sagar – to supply piped water to the city. Slowly people began to depend on local authorities for water. Still the majority of population depended on traditional sources.
Things changed in a big way after 1970s. On one hand the city was growing rapidly and on the other deep tube wells were introduced. Over a period of time, people abandoned shallow wells, tanks were closed and buildings came up.
Today the whole system upon which this tank system was built is being destroyed. Tanks are occupied for construction purposed, water is contaminated mainly due to sewage dispersal, discharge of industrial effluents and industrial waste and the whole tank system is endangered. Over usage of ground water and unregulated deep bore wells is resulting in rapid ground water depletion.
What happened to Rain?
In the past the rain used to fall on the ground. Part of the rain fall used be absorbed by the ground, often covered by grass and a few shrubs or trees. Rest of the water would flow out in small rivulets. Small rivulets would join each other and become bigger and bigger as they flow down due to gravity and become nallas. These nallas would either end up in tanks or in the river. There are several stages in which this process occurs. Usually the seventh stage is the last destination – tank or the river. The nalla is the fourth stage.
Now with all these building activities, the grounds on which they are built are flattened and cemented. That is, the first three stages lose their natural gravity flow. It is this water that creates puddles, water logging, clogs the storm drains and creates havoc with old buildings. Again it is this water that causes the traffic jams and makes the day for newspapers and TV channels. It creates a desperate situation. Nothing can be done about it expect to wait it out. (1)
So what is to be done?
When we talk about rain water harvesting, it is this water that we are talking about. Rain water harvesting is thus a desperate measure to met a desperate situation. It is not a long term solution. However it has the added advantage that it gives a short term relief both to the city’s problems – that of water shortage on one hand and that of tackling excess water during rains.
For the long term we have to assume a situation where there will not be petrol for tankers and electricity to pump water from rivers or from deep tube well. Yes in some cases roof top solar panel can provide electricity to pump water from deep tube well. But even for that to happen there should be water there!
So we have to go back to a situation when these cheap sources of power were not available. We have to understand that there will not be this metro city. The city will be divided in some 100 autonomous small towns. Some of the existing outlying high rise building conglomerates may turn ghost towns as they don’t have any local water.
A long term solution implies reviving the local river Musi, reviving the 500 tanks in the city and reviving shallow wells – both the community wells as well those in individual homes. All these require big mobilization of human and material resources and political will, all of which is lacking at present.
Rain water harvesting by individuals both at home level and at community level is a short term solution that will lead to a long term solution also. It will not only give immediate relief, it will also create awareness of the water problem as a whole and hopefully it will empower larger mobilization of resources to implement long term solutions.
(1) This section is based on a talk given by Anant Maringanti on May 15, 2016 during a Rain Water Harvesting Workshop at La Makaan, Hyderabad.
Frontier
Jun 5, 2016
Mayank Ale may be contacted at mayank.ale@gmail.com