The regional council's investment arm, HBRIC Ltd, the company promoting the dam and the Ruataniwha Water Storage Scheme (RWSS), had a claim to 10 million cubic metres of tranche 2 groundwater but withdrew its application last October, leaving the eight remaining applications.
These applications were currently on hold, awaiting more details on the augmentation schemes, but in the meantime residents in the Central Hawke's Bay townships have said allowing such a water take could have severe environmental and social consequences.
This week signatures were still being gathered for a letter to the regional council, adding to about 70 collected so far, to be sent on Friday this week.
Resident Bill Stevenson said that the townships had struggled with a depleting drinking water supply since 2004 when big irrigators began accessing the water.
In 2012, five houses ran out of water and over the years many had had to modify their existing bores to go deeper to reach the diminishing groundwater.
"I've done a rough estimate and I would say the people of Ongaonga have spent about $100,000 since 2004 on ensuring they have water.
"Any further water take from the Ruataniwha Basin groundwater means that individuals will be unable to supply water to their households and as such they will be forced to seek consents to drill new or extend the depth of their existing bores in order to be able to draw water for drinking and domestic household use."
He said protecting the loss of groundwater recharge on shallow bores and limited surface water could be the most important step the regional council could take to meet the community needs for a reliable, sustainable, safe water supply.
In the letter to the council, the residents called on the council not to approve any additional takes of tranche 2 water until it could be sure such extraction would not be likely to have an adverse effect on the townships' wells.
"If access to shallow groundwater via existing bores and wells in Ongaonga and Tikokino cannot be protected then the Hawke's Bay Regional Council needs to make provision to provide a convenient and suitable alternative solution at the cost of commercial consent holders," the letter said.
An update on the issue was being provided to the council's environment and services committee today and in a report to that meeting group manager regulation Liz Lambert said all the consent applications under tranche 2 needed to demonstrate that any effects on the surface and groundwater resources were acceptable.
"HBRC's science suggests that the allocation is not sustainable, therefore the applications have been placed on hold until further information is provided by the consent applicants."
She said the applicants had engaged Aqualinc to do some modelling on the stream depleting effects and any surface water augmentation requirements.
This process would take two to three months, after which the council would decide on whether to publicly notify the consents, and it also had the option for a wider review of Plan Change 6.
