No, river links and electric power grid is not similar.
We have national power grid networks to make sure that power plants in different regions can supply power over a large area. So if there is a local fault at some plant, the other plants can take up the slack.
That is exactly what linked river system will do. Flood waters in some areas will be diverted to regions with low water levels. Distribute waters of a large area and make more land fertile and cultivable. Develop fishing industry even in inland regions and kick start a water transport industry.
For rivers, diverting and affecting their natural courses and flows will have negative effects, especially on such a large scale. These rivers have been flowing in their natural form for thousands of years, and have supported civilizations during that time. It would be catastrophic to disrupt the natural form of these rivers.
Natural form of the river is changed every day. Sometimes in large demonstrable form or sometime in smaller changes that aggregate over time. The linked rivers will continue to support the same civilization but will also provide life line to other civilizations that is currently starved for water.
There are Negative effects and Positive effects to everything we do. That does not mean we stop doing anything. New waterways that will be build will also support the water ecology. More immortality water treatment plants will become necessary since we cannot divert sewage water into canals and feed that to the population.
If you want to store water for excess capacity, build dams or barrages. River Ganges, for example, is heavily polluted now. If you link it up to another river that is not as polluted, you risk upsetting the ecology of that river, not to mention that rivers have their own unique habitats/ecosystem. Some rivers are more saline than others, for example.
Dams serve a completely different purpose. Large ones are built to generate electricity. Check dams are built to check the flow.
Naturally there has to be guidelines for linking rivers. Pollution levels being one. That much is understood. Water salinity in the river waters do not vary greatly in India.
I think mankind should stay away from these kind of ambitious projects unless there is 100% certainty that there is no negative consequences.
Building smaller dams and tributaries might be one solution. But then dams themselves are controversial.
There will always be some Negative consequences, point is to take action when the positive consequence outweigh the negative.
As someone already has mentioned, these two are not similar. Please read the second post that I have made to this topic. Linking ganges to South India rever is not feasible since the canals or pipelines will have to cross bindha with an elevation of 500 meters on average which will cost enormous electricity. Secondly huge reservoirs need to be made to store surplus water in densely populated Northern states which is not possible.
It will also result in ecological disaster of great magnitude and existing flora and fona will be destroyed.
Better way is to link all south Indian rivers and make a full use of available water.
It is unlikely that linking Ganges to south India will be taken during the 1st Phase. First Phase will always be the low hanging fruit. Learnings from those will be used to chart the future.
Why are reservoirs required when they are not used now ? We are not talking about draining the river dry. Water levels in all linked rivers are regulated.
Some flora and fona will be destroyed and new flora and fona will develop in the linking canals and the linked rivers. The over all effect will be positive for the ecology.
Very interesting justification for water inter-link , we Chinese can maybe start with Bramaputra, this will regulate the water flow with the rest of our rivers
After our South-Noth water inter-link, we will take care of water resource in Tibet.
Yawn .......
First get the pollution levels in bejing down. ......then again don't. We really don't care either way.
if your people are happy with our plan then everything will be fine 
