The proposal is to increase production capacity by constructing a levee across Useless Inlet near the northern limit of the mining lease which is about 7 km from Clough's Bar.

The levee would be constructed of earthen materials taken from two quarries on either side of Useless Inlet and would have an engineering design similar to that of other breakwaters, such as at Hillary's Marina, with a relatively impermeable core of sandy material and an outer covering of rock.

There would be two tidal flap-gates that allow seawater to enter on flood tides but prevent its escape on ebb tides.