NEW DELHI, April 9 (Xinhua) -- Indian Supreme Court Monday reprimanded Prime Minister Narendra Modi's government for ignoring its order on framing a scheme for sharing water of a key river between two neighboring southern states, ordering its implementation without delay.

The water of Cauvery river has been a bone of contention between the neighboring states of Tamil Nadu and Karnataka for decades and now the issue has become politically volatile ahead of assembly elections in Karnataka next month.

"The central government knows what the scheme means," the top court said.

The court's direction came in the wake of Tamil Nadu filing a contempt petition against Prime Minister Modi's government for "willfully disobeying" its order on sharing water of Cauvery.

Tamil Nadu's petition said the central government failed to frame the scheme on Cauvery issue within the stipulated six weeks that ended on March 29, as directed by the court.

The crucial Cauvery river originates in the southern state of Karnataka and flows through neighboring Tamil Nadu before joining the Bay of Bengal. And both states have argued that they need the water for millions of farmers in the region.

In 2007, after decades of dispute over sharing of the river waters, the Cauvery Water Disputes Tribunal ruled that Tamil Nadu state would get 419 billion cubic feet of water a year, while Karnataka would get only 270 billion.

But in February this year, the Supreme Court curtailed Tamil Nadu's share of the river water but compensated it by allowing the extraction of 10 billion cubic feet ground water from the Cauvery basin. The court also ordered the central government to form a scheme to implement the water sharing.