The union said if the water systems were not managed carefully, a situation could develop where parts of the province could run the risk of floods.
According to information from the department of water affairs on 11 March, 1 450m³ of water/second flowed into the Vaal Dam, while the outflow was 940m³.
According to Johan van Rensburg, Agri Northern Cape general manager, the Bloemhof Dam was 81% full and would be 100% full within the next couple of days. The inflow into this dam stood at 700m³, 400m³ was being released.
Van Rensburg said the lower Vaal area around Douglas could only handle 800m³ beore the rivier burst its banks.
The Gariep Dam was 93% full on 11 March and the Van der Kloof Dam was 100% full. Outflow was 200m³ each.
Representatives of Agri Northern Cape suggested the outflow of the Bloemhof Dam be increased to 700m³ and the outflow of the Van der Kloof be increased to at least 600m³.
Van Rensburg said it was important that inflow projections be used to determine the optimal outflow to prevent possible flooding.