Cast iron siphons

Year proposed

  1858

Status

  Not implemented

Location description

  Gravel barrier at Taumutu

Description of option

  A series of cast iron syphons (approx 8 or 9 syphons) was proposed as an option to drain the lake.

Opening, closing, and lake level control description

  Continuous low flows and good opening & closing control but less than ideal lake level control (unless many used). Ends of pipes must always be submerged to operate.

Maximum discharge

  below 50 cumecs

Maintenance/Management description

  Width of shingle bank (+ need for ends to be continuously submerged)  requires long pipes - which need protection from waves & gravel.

Cost description

  "Pipes alone amount to double the price approximately of the land drained without allowing anything for timber foundations or casings" (Bray, 1875 in Harris, 1947).

Fish passage benefit rating

  Low

Potential running impacts or benefits