Lower Wairarapa Valley flood control and land reclamation scheme

Engineering Work (eg road, bridge, sawmill, dam)

One of New Zealand’s largest flood control and land reclamation developments. Work on this scheme was carried out between 1964 and 1984.

It involved  reorganising a major river system in an intricate manner and the primary contract attracted world-wide attention. The floodgate at Kumenga, on the Raumahanga River, needed special foundation design owing to its location on recent marine deposits.

One unique feature was the large amount of land which was reclaimed for agricultural and pastoral use. The increase in agricultural production has been significant. Special provisions were also made for the enhancement of wildlife in the latter stage of the construction period.

Principal designer: Wairarapa Catchment Board
Major contractors: Costain Blankvoort (UK) Dredging Co Ltd (river widening and stopbanking) Downer & Co Ltd (floodgate barrage)

Heritage recognition
IPENZ “Engineering to 1990” project
This item of New Zealand’s engineering heritage was recognised as part of the IPENZ “Engineering to 1990” project which the Institution organised to help celebrate the country’s sesquicentenary in 1990. A plaque was unveiled to mark the significance of this flood control system as part of the development of the nation.


No Attachments

East West Access Road, Kumenga, Lower Wairarapa Valley


Access Info
The overall scheme and sluice gate structure can be viewed at all times from the road. East West Access Road crosses over the sluice gates.

Nature of Engineering
Infrastructure (incl. Road, water, ports), Natural Hazard Protection

Lat: -41.314507 Long: 175.193535