The Direction requires Opuha Water Limited to maintain a minimum flow of 3.5 cubic metres per second in the Opihi River (at the Saleyards) when the lake is above 375 metres.
The lake level is currently around 378.9 metres. The Opuha Environmental Flow Release Advisory Group, comprising representatives from district councils, farmers, Opuha Water Limited, river users and tangata whenua, agreed to drop the release from 4.5 to 3.5 cubic metres for a 14-day period to enable minimum water release from the Opuha Dam in order to build up water storage. There are no irrigation restrictions in this Direction.
Environment Canterbury has authority under Section 329 of the Resource Management Act 1991 to notify the Water Shortage Direction.