the cleansing, widening, deepening, covering or otherwise improving of existing waters;

the dredging and maintenance of channels;

the cutting of new drains where required;

the abstraction from any source of any water necessary to the purposes of navigation;

the construction of locks, dams, culverts, overflow culverts, pumping stations, aqueducts or viaducts;

the raising and repairing of existing embankments, and the construction of new embankments;

the sinking of pumping sumps;

the construction and repairing of sluices or valves;

the removal and disposal of old spoil banks;

the construction of hydro-electric power stations in connection with any pumping station or pumping sump.