Kahikatea trees in a Hawke's Bay reserve are "dead and dying" from a lack of water, while water is being wasted by irrigators nearby, Forest and Bird says.
Central Hawke's Bay Forest and Bird co-chairman Clint Deckard says the shallow-rooted trees of Inglis Bush reserve are suffering in dry soils because groundwater levels in the area are low as a result of "over-allocation to agriculture".
Deckard said an irrigator was recently spotted spraying and "wasting thousands of litres of water" on a local road.
"It is very disappointing to see ancient trees dying whilst a nearby irrigator is wasting water," Deckard said.
Gerald Wilson owns the farm where the wastage occurred and says he is devastated at the incident.
"We lease that land out to squash farmers ... and they get spraying contractors in to move and set up the system," Wilson said.
"Someone has obviously come in and set the system up wrong and not taken any notice of where it would spray."
Wilson says he's disappointed to have been linked with tree deaths by Forest and Bird and has a proud history of being conservative with his farm's water use.
"I run this farm very water consciously and everyone knows how hard it's been for us down here and we're not going to waste water like that," Wilson said.
"I'm on the local water usage group and play a big part in how we manage our water systems."
Deckard said low groundwater levels below the reserve have been a long-standing problem. He claimed Hawke's Bay Regional Council had not dealt with the challenge despite warnings more than 20 years ago by the Department of Conservation.
A Landcare report in 1996 recommended DoC apply for consent to take 10 litres per second from the Tukituki River for the reserve to compensate for the failure of springs due to "agricultural extraction".
The report also stated that the reserve "should be regarded as having as much right to water as any other land use or user. At present, increased agricultural use is already seen to be prejudicing the reserve, as manifest in the failure of the seepage springs".
HBRC scientist at the time Dr David Dravid is quoted in the report as saying "the reason for the loss is almost certainly associated with water extraction for agriculture, coupled with the interconnection of aquifer lenses by new deep bores".
Deckard said if the HBRC submitted to pressure from a small group of users to take deep "Tranche 2" groundwater or follow through with a proposal to revoke a recent increase in the minimum flows for the Tukituki River, the kahikatea would have no chance of survival.
"We risk losing this forest and all the wildlife that relies on it. The bush and the river are not healthy under the current regime and cannot wait any longer. This forest deserves the water just as much as any other irrigators," Deckard said.
A HBRC spokesman said the Tranche 2 water, which is a groundwater removal plan, had not been put in place yet for it to be used.
"The Tranche 2 water has not been allocated and the trees are dying in advance of that so the regional council is keen to understand why they are dying now and also whether the Tranche 2 water would have any further effect on this."