Posts Tagged ‘catchment management’


Requiem for our rivers

March 10, 2008

This is a column I have in The Hindu. It appears every Saturday in the supplement called Property Plus. This is last weeks article.


Requiem for our rivers S. VISHWANATH

Price of development: Copious flows in the Arkavathi is a thing of the past. This is a requiem for the Arkavathi and most of our peninsular rivers. The Arkavathi is a tributary of the Cauvery. Rising in the Nandi Hills to the north of Bangalore it passes through most of Bangalore Rural district and joins the Cauvery at Sangama in Kanakapura district. It flows for 190 kilometres and in hydrological parlance is called a second order stream, meaning it is a tributary of the Cauvery which joins the sea. The Cauvery is a first order stream flowing into the sea, its major tributaries are second order streams and the Vrishbhavathi which joins the Arkavathi is a third order stream. The catchment area from where the water collects in the river is more than 4000 square kilometres. Yet the Arkavathi is dead and barely flows during heavy rains. Why is that so? This is a sorry tale of the death of a river.When Bangalore first ran out of water from within its boundaries in 1894 it was decided that a reservoir at Arkavathi would need to be built to ensure that enough water was available to the city. The Hessarghatta reservoir, about 24 km from the city, was built on the Arkavathi and continued to supply water till about 1934 when the second reservoir on the Arkavathi called the Thippagondanahalli or the Chamaraja Sagara Reservoir was constructed to bring in more water for the increasing thirst of Bangalore.

Both reservoirs were built on the Arkavathi for The Gazetteer of Bangalore Rural says the Arkavathi “is not exactly a seasonal stream, in the summer months it presents the usual aspect of a sandy bed with a small current of water flowing at one side.” In short it was a perennial river. Large tanks such as the Madhure and the Dodballapur ere also constructed on the river and would usually fill up. The town of Dodballapur depended on the Arkavathi for its drinking water requirement as did the town of Ramanagara.

Groundwater was available at 1 to 3 metres below ground level in the Arkavathi basin. Wells ranging from 2 to 10 metres in diameter and depths of between 3 to 12 metres provided up to 60,000 litres of water per day. In summer, well water would fall at best to 4 metres. Wells provided drinking water for all villages as well as agricultural water for irrigation. More than 30,000 wells were present in the Arkavathi basin. This was the situation till the 1980s.

Pressure What killed the Arkavathi? A combination of the natural phenomena of drought and pressure on the catchment of the river. From 1980 to 1987, six out of the eight years were drought years with below normal rainfall. Wells dried up and were replaced by deep tubewells and borewells. Over-pumping resulted in a steep fall in the water table with most wells drying up and a competitive deeper drilling of borewells resulting in depths of nearly 300 metres being reached. With the fall in the groundwater table there was no base flow into the river. It first dried up in summer but then was unable to flow in the rainy season except for a few days. The tanks and the channels leading to the tanks were encroached upon or mismanaged and the links of surface water flows to the river stopped. All the tanks dried up and the Hessarghatta was abandoned as a reliable source of water to the city. The same fate awaits the Thippagondanahalli in a few years when it too will cease to be a reliable source for storage. The Nagarakere or the Dodballapur tank was long since given up as a source and the drinking water situation there is perilous with most water coming from private tankers. Villages struggle for drinking water in the basin especially in summer as borewells go dry.

The change of land use to predominantly agricultural activities resulted in the levelling of land and the construction of field bunds. Ploughing of land was a natural corollary to farming activities. Runoff from the land became zero. Sand mining and granite quarrying disrupted rivers badly and added to the problem.

Then came the industries with their huge water demand. The apparel park set up in Dodballapur in the Arkavathi basin will need water from the Cauvery and so will the international airport in the Dakshina Pinakini basin. The second order streams are dead and the first order Cauvery is the only reliable source. The question is for how long?

What does it mean for property? In the absence of any river basin- level institution even at the second order stream level, who will be responsible for the planning of the rivers and waters both above the ground and below the ground? Who will plan, invest and manage the waters of our rivers and who will be held accountable for failures?

With the coming up of the international airport a property boom is on in Dodballapur. Land prices have skyrocketed and housing colonies, resorts, restaurants and apartments are seeking to locate themselves there. But where is the water for this development?

Unless we create the right institutions at the right river basin level and arm them with the ability to plan and act on the plan, water shortages will be the order of the day and will hinder livelihoods and economic growth. Agencies such as the Bangalore Water Supply and Sewerage Board are woefully inadequate to manage sources and to provide water for all.

This is true of ALL our second order streams and it is a matter of time that climate change hits us and starts affecting first order rivers.

Water wisdom lies in recognising problems at the scales at which they occur and taking remedial action at that scale legally, institutionally and financially so that the problems are overcome.

Economic development and poverty reduction will be hit unless ecological resources are taken care of and that is the responsibility of ALL of us as citizens of the country. Recognise the river basin you are in and take action to revive it.

Water wisdom is leaving things better for the future generations than what we inherited.