Rivers

Narmada valley is facing yet another crisis beyond the gigantic dams, which has arisen due to the huge canal network of the Indira Sagar and Omkareshwar canals. The canals of these two dams are not yet fully planned, yet certain estimates, which are not yet final by the Narmada Valley Development Authority show that not less than 10,000 hectares of agricultural land is to be acquired, but a larger acquisition is yet to come up in numerous villages, where even a basic socio-economic survey of the affected land and families is yet to be undertaken.

In the light of the recent major floods in river Yamuna, the enclosed article that deals with the question and futility of man made structures like dams and embankments to control floods may be found useful.

But it is unfortunate that even this otherwise very insightful article does not reflect anywhere on the fact that the floods in monsoon months are natural events and should be acknowledged and planned for accordingly.

There is a need to better understand the phenomenon of floods and not to treat them as some kind of natural calamity requiring artificial man made safeguards.

It may be noted that Dr D K Mishra who has studied the floods in river Kosi for decades has been making these points for many years now. It is necessary to heed to people like him if we do not wish to invite more trouble in future.

This link on the CAG website provides the details of an international conference that was held on 15-16 March 2010, in the backdrop of the environmental audit proposed by the the Comptroller and Auditor General (CAG) of India, for management and conservation of the environment .

The purpose of this conference was to deliberate on the causes of pollution, action taken by governments and civil society to address this and environmental, management and legal interventions needed to put lakes, rivers and ground water on the path of sustainability.

More than 20 experts on water and water pollution issues were invited to share their views as panelists during the conference. Apart from these distinguished panelists, the heads of supreme audit institutions from countries like Austria, Maldives, Bangladesh and Bhutan were also present to share their experiences regarding audit of water pollution in their countries.

Dr G.D. Agrawal’s tapasya, his third fast-unto-death, has finally achieved the desired result.  Since 2008, Dr Agrawal has been trying to persuade the Government of Uttarakhand and the Government of India that R. (Bhagirathi) Ganga must be allowed to flow in its natural state in the uppermost reach between Gangotri and Uttarkashi.  The two governments had plans to construct three new large hydropower projects in this stretch.  Dr Agrawal’s fasts have led to the scrapping of all the three projects.

The quantity and seasonality of water flow in a river may greatly change from its normal condition between a major storage and downstream, thus paving the way for drastic changes in the riverine ecosystem. ‘Environmental flow’ refers to the amount of water considered sufficient for protecting the structure and function of an ecosystem and its dependent species.

The paper goes on to describe the case of river Bhadra, which is the site of a dam that has significantly altered the natural flow of the river and describes the study that aimed at conducting the environment flow analysis of the river.

This document published by IWMI and CGIAR describes the details of the Polavaram project, which has been planned by the state of Andhra Pradesh as a multi-purpose project:

• to provide irrigation benefits to the upland areas
• to provide a water supply to the industries in Visakhapatnam city, including the Steel Plant, for the generation of hydropower
• for the development of navigation and recreation facilities.

The project envisages the construction of an earth-cum-rock filled dam that is 1,600 m long across the Godavari River at Polavaram, and about 42 km upstream of the Godavari Barrage at Dowlaiswaram.

The paper highlights the case of recent projects that have been planned on the river Cooum in Chennai.

This report deals with the social conflicts emerging out of the encroachments owing to the change in course of the Ganga upstream and downstream of the Farakka barrage. The barrage was built with the intention of diverting water into the Hugli river with a view to flush the sediment load into the deeper part of the estuary and revive the navigational status of Kolkata port. During the last three decades of its operation, the silt-management in the barrage was given scant or no attention. The sediment movement in the tidal estuary of Hugli is a function of a complex fluvial system that can hardly be governed by inducing 40000 cusec of water.

The study deals with flood plain mapping in a part of Yamuna basin between Gangoh and New Delhi. A flood is a markedly high stage of flow in a river and may inundate adjoining lands, which is called the floodplain of a river. So, floodplain is land inundated by a flood of given frequency. Alternately it is also defined as flat land between valley walls.

The report deals with Geographical Information Systems (GIS) based rainfall-runoff modeling using Topography Model (TOPMODEL) for the Hemavathy catchment of Cauvery basin in Western Ghats of Karnataka. The TOPMODEL is a variable contribution area model in which the predominant factors determining the formation of runoff are represented by the topography of the basin and a negative exponential law linking the transmissivity of the soil with the vertical distance from the ground level.