New Delhi, Aug. 12 -- The Supreme Court on Wednesday observed that the repeated extension of a law providing temporary protection to unauthorised colonies, slums and constructions in Delhi has contributed to "ad-hocism" in Delhi's governance and could undermine any action plan to remove encroachments from the Yamuna riverbed.

The court was hearing proceedings on the preparation of a comprehensive Yamuna Action Plan (YAP) for conservation of the river, which flows through Delhi and several other states. In May this year, the court had constituted a committee headed by the Union home secretary to prepare the plan.

A bench of justices Manoj Misra and Manmohan said the continued protection provided under the National Capital Territory of De...