This council publicly notified the Water Plan on 28 February 1998. Following submissions, hearings and appeals, ORC made the plan operative on 1 January 2004. The tables below list changes to the plan since then.
| Key Event | Date Notified | Date Decision Released | Date Operative |
| Regional Plan: Water for Otago (the Water Plan) | 28 February 1998 | 7 July 2000 | 1 January 2004 |
| Waitaki Catchment Water Allocation Regional Plan (This information is from ECan) |
19 February 2005 | 30 September 2005 | 3 July 2006 |
| Key Event | Date Notified | Date Decision Released |
Date Operative |
| Amendment 1 (NPS Freshwater Management) | 24 June 2011 | 24 June 2011 | 1 July 2011 |
| Amendment 2 (NES Plantation Forestry) to the Regional Plan: Water | 30 June 2018 | 30 June 2018 | 1 July 2018 |
| Key Event | Date Notified | Date Decision Released |
Date Operative |
| Plan Change 1A | 17 Aug 2005 | 01 Apr 2006 | 01 Aug 2006 |
| Plan Change 1B (Minimum Flows) | 20 Dec 2008 | 31 Oct 2009 | 01 Mar 2010 |
| Plan Change 1C (Water Allocation and Use) | 20 Dec 2008 | 10 Apr 2010 | 01 Mar 2012 |
| Plan Change 2 (Regionally Significant Wetlands) | 02 Jul 2011 | 12 May 2012 | 01 Oct 2013 |
| Plan Change 3A (Minimum Flow for Taieri River at Tiroiti) | 26 Jun 2010 | 11 Dec 2010 | 01 May 2011 |
| Plan Change 3B (Pomahaka Catchment minimum flow) | 16 Aug 2014 | 14 Feb 2015 | 01 Jun 2015 |
| Plan Change 3C (Waiwera Catchment minimum flow) | 13 Dec 2014 | 08 Aug 2015 | 01 Mar 2016 |
| Plan Change 4A (Groundwater and North Otago Volcanic Aquifer) | 18 Sep 2010 | 24 Sep 2011 | 01 Mar 2012 |
| Plan Change 4B (Groundwater allocation) | 17 May 2014 | 13 Dec 2014 | 01 Sep 2015 |
| Plan Change 4C (Groundwater management: Cromwell Terrace Aquifer) | 16 Aug 2014 | 13 Dec 2014 | 01 Sep 2015 |
| Plan Change 5A (Lindis: Integrated water management) | 08 Aug 2015 | 13 Aug 2016 | 05 Mar 2022 |
| Plan Change 6A (Water Quality) | 31 Mar 2012 | 20 Apr 2013 | 01 May 2014 |
| Plan Change 6A Archive | 31 Mar 2012 | 20 Apr 2013 | 01 May 2014 |
| Plan Change 7 (Water Permits) to the Regional Plan: Water | 18 Mar 2020 | 17 Nov 2021 | 05 Mar 2022 |
| Plan Change 8 (Omnibus Plan Change) | 06 Jul 2020 | 31 Jan 2022 and 21 Apr 2022 (for primary sector provisions) |
4 Jun 2022 (partially operative; primary sector provisions) |
| 14 Jun 2022 | 3 September 2022(fully operative) |