Elevated Lock with Sluice gate
Taumutu, Harts Creek
Description of option
An elevated lock and sluice gate near the current opening site was proposed to reduce the amount of mechanical work required by the machinery, and to enable an opening to be created in a shorter time. Langbein proposed closing off the small arm of Lake Ellesmere at Taumutu - diverting Harts Creek into this part of the lake. This inflow could be supplemented by pumping water from the lake proper if required. This smaller lake would be managed by the control of sluice gates which would be opened into a channel leading into the pilot cut and out to the opening.
Opening, closing, and lake level control description
Could significantly reduce machinery hours per opening and hence decrease costs. The final cut can be made using the water from the lock to open the lake in bad weather, and once open, help maintain an opening in less ideal circumstances.
above 300 cumecs
Seepage of water through shingle bank may make it impossible to raise water in lock sufficiently.
A large diversion such as this would be uneconomic.
Fish passage benefit rating
Potential running impacts or benefits
Environmentally & culturally incompatible.