A city is not isolated from the river basin it is located in. It has to interact, understand and manage its water demand in the context of this basin.
The city of Bangalore, for example, is only partially located in the Cauvery basin as it discovered when the Cauvery river water tribunal was deciding on the allocation of waters to various demands in the entire basin.
When water allocation had to be made between States, the primary demands listed were for agriculture, domestic needs and industrial demand. These are often competing demands even within States.
Direct impact
What are the direct consequences of not engaging with a river basin and its demands? Rivers can dry up and sources become no longer reliable. The Arkavathi, for example, has dried up primarily because land use has changed in the upstream areas of the river and agriculture has consumed surface and groundwater at unit levels which no longer permit water to emerge in rivers either as surface flows or as groundwater base flows.
Managing the forests and agriculture as well as groundwater therefore becomes crucial for a city.
Waste-water flows from the city too go to the basin inevitably, impacting the quality of river water and groundwater quality. The Vrishbhavathi, for instance, is a perennial sewage flow messing up the lakes and reservoirs built on it as well as the river itself, causing countless harm to the farmers depending on the river for livelihood as well as impacting the food and vegetables produced for the city. The Musi in Hyderabad is another classic example as is the Cooum in Chennai.
The seriousness
So, what happens when basin planning is not done? When unplanned and unregulated, competing demands from agriculture, industry and the city cause conflicts between farmers and several others.
When the reservoir on the rivers feeding water to cities also has to release water into the canals for irrigation, tension mounts and the certainty of receiving water comes into doubt for all consumers.
Contamination
Food crops and vegetables coming into the city can become contaminated with the sewage from the city itself. Industrial production may need to stop and factories close for want of water. Energy generation from thermal and hydro power units will slow down as the water runs out.
It is time the city thinks beyond itself and learns to engage with its catchment and its basin to plan and manage water better. That would be water wisdom.
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