The 1969 MAA
In 1948, Alberta Saskatchewan, Manitoba and Canada signed the Prairie Provinces Water Board Agreement. This Agreement established a Board to recommend the best use of interprovincial waters, and to recommend allocations between provinces. After some twenty years, changes in regional water management philosophies resulted in a need to modify the role of the Board, Consequently, the four governments entered into the Master Agreement on Apportionment on October 30, 1969. This Agreement provided an apportionment formula for eastward flowing interprovincial streams, gave recognition to the problem of water quality, and reconstituted the Prairie Provinces Water Board. The Agreement continues forever unless all the Signatory Parties formally change the Agreement.
The Master Agreement on Apportionment contains an introduction and five schedules. These Schedules are:
- Master Agreement on Apportionment - The main body of the Agreement
- Schedule A - An apportionment agreement between Alberta and Saskatchewan.
- Schedule B - An apportionment agreement between Saskatchewan and Manitoba.
- Schedule C - the Prairie Provinces Water Board Agreement describing the composition, functions and duties of the Board.
- Schedule D - A listing of Orders-in-Council for allocations of interprovincial waters made before 1969.
- Schedule E - A Water Quality Agreement describing the role of the PPWB in interprovincial water quality management and establishing PPWB Water Quality Objectives for 12 interprovincial river reaches. This Schedule became part of the Master Agreement in 1992. Interprovincial Water Quality Objectives were updated in 2015 and in 2021.
The Master Agreement on Apportionment has been amended in 1984, 1992 and 1999. The three amending Agreements are:
- Amending Agreement to the Master Agreement on Apportionment and to the First Agreement (1984).
- Amending Agreement to the Master Agreement on Apportionment and to Schedule C (1992).
- Amending Agreement to the Master Agreement on Apportionment and to Schedules A, B and C thereto (1999).