Mechanical options refer to methods used to mechanically open the Kaitorete Barrier to allow the Lake to drain to the sea. These opening options are linked to a specific opening trigger Lake level. Mechanical opening have been the prefered option of opening the lake.
- prior to 1868: local Maori were know to have let the lake out to protect the Pa at Taumutu by using various escavation methods
- 1868 to 1904, 1925-1931: use of horse drawn scoops
- 1931: Ellesmere Drainage Board purchased power scoops
- 1947: North Canterbury Catchment Board took responsibility using bulldozers and draglines.
- Currently: Environment Canterbury is responsible for the opening using hydraulic excavators