I have a problem of designing a salinity barrier on a river flowing through a large agricultural area, susceptible for flooding, to prevent saltwater intrusion to domestic water supply intakes. There is a controversy between the farmers and the water supply agencies regarding the size (total width, the number and opening sizes of gates, the sill & crest levels and the operation system of gates etc.) of the structure. I am seeking for the advice of experienced expertise regarding the criteria to be adopted in sizing the structure to prevent saltwater intrusion and safeguard the lands against flooding.