Drilling down at Uawa

Credit: Murry Cave/Gisborne District Council. Caption: Bore drilling in the Ūawa Hikuwai Catchment — Tolaga Bay Flats — is complete, with four of the 11 bores established permanently.

Scientific bore drilling in Ūawa is complete, the result of a historic aquifer agreement made last year.

In December, a memorandum of understanding was signed between Te Aitanga ā Hauiti and the Gisborne District Council, creating a partnership for the testing and measuring of underground water in the Ūawa Hikuwai Catchment — the Tolaga Bay Flats.

The agreement meant that in partnership with mana whenua, the council could drill groundwater monitoring bores to analyse both the quantity and quality of aquifers in the area.

Eleven exploratory pilot bores were drilled on the flats between March 2020 and October 2021, with four established as permanent groundwater monitoring sites.

The other seven were decommissioned because of high gas levels and the presence of salt water.

On Thursday, Gisborne District Council environmental science and monitoring manager Tom Porter told councillors the work was important for allowing the community to know the state of their water going forward.

“We went in and did some scientific bore drilling in Ūawa where we didn't have any information on the aquifers,” Mr Porter said.

“I feel we truly did it in partnership with the local community.”

Part of the reason for the project — which came in under budget at $208,790 according to the last financial update in June — was to fulfil the council's obligation under the National Policy Statement for Freshwater Management.

Before the project, the council had no groundwater monitoring bores in the catchment.

The bores would allow the council and local community to monitor whether salinity was increasing due to sea level rise caused by climate change, the report presented to council said.

Also presenting at Thursday's meeting was Te Aitanga ā Hauiti mana kaitieki representative Anne McGuire, who provided a history of the sites.

The mana kaitieki group is affiliated to the iwi, and has been dealing with resource management issues in Ūawa for 30 years.

It is made up of representatives from seven marae.

Sites discussed included Paroa Rd (the long village), which McGuire said was once a māra kai (food garden).

“It became important because the people who lived in that pa were the gardeners. They fed the students at the whare wānanga.”

Across from the Paroa site was Mangatuna, which had been bought back in the past five years, McGuire said.

“That site, among other sites, we lost around 1874 with the New Zealand Settlement Company. Gradually, we're getting them back.”

Another site, Wharekaka, was a sore point because of how its history had been locked up.

Following World War 2, it was gifted for rehab farming, but none of the tīpuna who fought were balloted to those farms, McGuire said.

It was now a dairy farm.

At Waipurupuru, salination levels were “right up” — an interesting finding considering the area had been used for food gardens between the 1400s and 1800s when salination didn't come so far inland, Mrs McGuire said.

Other areas tested included Sandy Lane, the golf course, Lockwoods, and Thompsons Paddock.

The hydrogeological report recommended no further drilling should be undertaken in search of non-saline groundwater across the Ūawa Hikuwai Catchment unless robust research indicated it would be successful in finding a prospective aquifer.