Century-old watercourse drying up

FAILED: The Ruamahanga River at Te Ore Ore can no longer easily feed a water race that supplies farms and lifestyle blocks. PHOTO/FILE

Degradation of the Ruamahanga River appears to have sounded the death knell for the Te Ore Ore Water Race which has been supplying farms with stock water for 100 years.

The water race is the smallest of three controlled systems in Wairarapa, the others being Taratahi and Moroa, and is due to be shut down by Masterton District Council on June 1 ending supply to the two dairy farms, two sheep and beef farms and 16 lifestyle blocks that feed from it.

Behind the decision is gradual degradation of the river bed, which has seen a drop of about 1.5m to 2m in the stretch between Double Bridges and Wardell's Bridge.

The intake for the gravity-fed water race, which is in Black Rock Rd and not too far from Te Ore Ore Marae, is now well above the water channel.

Up until now the water race has been maintained by repetitive and expensive channel work to ensure the flow remains near the intake structure.

Leading up to the planned closure, the council called a public meeting last Monday and called for submissions, which will close on March 16.

Most affected by the closure will be the dairy farmers who use water from the race for both irrigation and stock water. They pay 80 per cent of rates levied on the system and use - according to the council - 10 times more water than other users.

Greater Wellington Regional Council believes it may be possible to transfer water-take consents for the water race to property owners for irrigation.

In 2013 the district council commissioned Eastern Consulting to report on the water race. It produced four options. Apart from closing the race down, these were: constructing a pump station, relocating the intake 300m further up the river or building a weir across the Ruamahanga.

Installing a pump station would cost between $250,000 and $400,000 and require a power supply at the intake site.

Moving the intake could cost up to $600,000 and would be opposed by the regional council over concern for integrity of the river bank during floods.

Building a weir would also get the thumbs down from the regional council as it would restrict the passage of fish and interfere with recreational river uses.

District council assets and operations manager David Hopman has acknowledged that aside from providing stock water, the Te Ore Ore Water Race drains farmland, helping to minimise flooding on nearby properties.

With the closure of the water race, a drainage scheme would have to be set up and a proposal to use the closed race as a channel had been discussed at a meeting in mid December.

Mr Hopman said several issues needed to be clarified if the closed race was used as a drainage channel. The most important was the need for an agreement with property owners to set up a scheme and for the costs and maintenance to be "agreed and apportioned."

Eastern Consulting had warned that without a scheme in place, partial or complete filling in or abandonment of the closed race would lead to stormwater problems after heavy or prolonged rain.