Dravida Munnetra Kazhagam (DMK) working president MK Stalin was detained on Sunday amid a protest against the Centre over the constitution of a Cauvery Management Board (CMB).
Earlier in the day, DMK announced to observe a shutdown across Tamil Nadu on April 5 to press for their demand of formation of the CMB.
The DMK even sought support from the ruling All India Anna Dravida Munnetra Kazhagam (AIADMK) for the protest.
The six-week time frame directed by the Supreme Court to set up the CMB ended on March 26, after which the state government stated that they would re-approach the apex court.
The Supreme Court had on February 16 pronounced its verdict on the vexed dispute between Tamil Nadu and Karnataka.
The apex court directed Karnataka to release 177.25 thousand million cubic feet (tmcft) of water to Tamil Nadu. This reduced Tamil Nadu's share of Cauvery water by 14.75 tmcft from the 192 tmcft allocated by a tribunal in 2007.