When Water Apportionment Accord (WAA) was signed between provinces?

WAA stands for Water Apportionment Accor.
This agreement was about sharing of water of Indus River among provinces.
All provinces claimed for injustice of distribution of water of Indus River.
This agreement was signed between provinces on 16 March 1991,
This agreement basically consist of 14 condition.
According to WAA, Punjab Province can uses 37% water of Indus River. Sindh Province can uses 37% water of Indus River. KPK Province can uses 14% water of Indus River. Balochistan Province can uses 12% water of Indus River.