Map rejig gives Auckland's biggest dam to Waikato

The Mangatawhiri dam has only half the storage capacity of the Mangatangi dam. Photo / Kenny Rodger

Auckland's largest water storage dam and two regional parks would be transferred to the Waikato District Council if one of the recommendations of the Royal Commission on Auckland Governance is accepted.

In its report, the commission supports calls from people in Kaiaua on the Firth and recommends a boundary carve-up of the Hunua Ranges that transfers Kaiaua from Auckland to the Waikato District Council's region.

But the change also makes the Mangatangi dam and the Whakatiwai and Waharau regional parks part of Waikato.

The Waikato area includes an important kokako recovery bird programme.

The Mangatangi dam has a storage capacity of 35.3 million cubic metres of water, twice the size of Auckland's next biggest dam, the Mangatawhiri dam, also in the Hunua Ranges.

Waharau Regional Park is the eastern gateway to the Hunua Ranges. Whakatiwai is a small and undeveloped regional park with a series of gravel ridges that are unique to Auckland and are internationally significant.

In its report, the commission accepted the validity of Kaiaua residents' submissions that the Hunua Ranges separated them from Auckland and they looked to the south for shopping and education.

"The fact that two regional parks will be outside the Auckland Council area is not seen by the commission as presenting practical difficulties," the report said.

The commission's reasoning has not impressed Auckland Regional Council chairman Mike Lee, who has expressed concerns about the loss of the dam and parks in a letter to Local Government Minister Rodney Hide.

ARC parks and heritage committee chairwoman Sandra Coney said yesterday there was no logic to severing part of Auckland's essential water infrastructure and passing the ARC's experience managing regional parks to a council with no experience.

"It's a completely unnecessary complication," she said.

"It just looks like a line was drawn on a map without realising the complications it would cause."

Sandra Coney said Aucklanders' investment and recreational use of the water catchment and regional park facilities in the Hunua Ranges outweighed community of interest arguments from Kaiaua residents.

Waikato District Mayor Peter Harris was surprised the council had picked up Kaiaua and missed out on the towns of Tuakau, Pokeno and Mercer, which were brought into the new Auckland Council.

The district wanted the southern boundary drawn at the Bombay Hills, instead of aligning with the Waikato River, he said.

Waitakere Mayor Bob Harvey has also written to Mr Hide raising concerns about the royal commission's report.

He and Mr Lee agree on the need for a strong new regional body, but have serious reservations about local democracy.

Mr Harvey said: "If the proposed reforms of local government fail to deliver outcomes at the local level, Auckland will go backwards."

Mr Lee said the royal commission's proposal was too complex and in practical terms would be very difficult to implement in time for the October 2010 local body elections.