Franklin can water its way to greater prosperity
Auckland Regional Council hydrogeologists have great news for vegetable growers around the Pukekohe township and hill,
recommending a doubling of water available from the Pukekohe volcanic aquifer (a natural underground reservoir) in new
draft ARC water allocation guidelines.
ARC hydrogeologist Zeljko Viljevac has found that more than double the amount of groundwater previously available can
now be sustainably allocated from the Pukekohe volcanic aquifer. This is great news for growers as water demand has
increased since the 1980s and water from the aquifer was fully allocated under previous guidelines.
“Our improved scientific understanding of the way that the Pukekohe and Kaawa aquifers function means more water will be
available and Franklin’s potential for food production is enhanced,” said ARC councillor representing Franklin, Dianne
Glenn.
“Our current guidelines for water allocation were intentionally conservative, based on information we had available. The
ARC has analysed exactly how the aquifers are being replenished and how much groundwater can be made available to local
users,” said Cr Glenn.
“If we had over-allocated these resources, water levels could have dropped and affected people’s access to water and
their livelihoods. We are aiming to ensure that water allocation in Franklin is sustainably managed to provide long-term
certainty for water users,” said Cr Glenn.
Most of Franklin’s water supplies, for municipal use and horticulture, is taken from two underground aquifers. The Kaawa
aquifer covers an extensive area, from Karaka to the Waikato River. Overlying it are the volcanic rock aquifers of
Glenbrook, Pukekohe and Bombay.
Information collected on water levels and water use over the last 15 years, funded in part by resource consent holders’
annual charges, has provided the base information for this work. This has enabled ARC to revise management guidelines
for the water resources. The major finding is that the Kaawa aquifer is recharged with rainwater mainly through the
volcanic cones like Pukekohe hill. Each volcanic cone is a porous pathway for water to get down into the lower aquifer.
Water Resources Scientist Greg Murphy says now that the ARC understands more about the Pukekohe Volcanic Aquifer, it has
been divided it into smaller more precise management units. “We needed to know how the Kaawa aquifer was recharged, to
make sure it is getting enough water,” said Mr Murphy.
“We have also found that the aquifers are sensitive to climate variation, so we need to continue to keep an eye on water
levels, especially now that we are looking to allocate more water.
“It’s more important than ever for water users to meter and report back to the ARC how much they’re using,” added Mr
Murphy.
The ARC’s Environmental Management Committee received the Kaawa Aquifer report on 26 November, and asked staff to
consult with the community on the draft management guidelines.
ARC staff will be approaching representatives of the water users, Franklin District Council, Environment Waikato,
tangata whenua and other interested parties to explain the findings and ask for feedback and input into the new
management guidelines. A newsletter explaining the results of this work will also be sent to all resource consent
holders.
The aquifers cross the regional council boundaries into the Waikato region and ARC is keen to fully involve Environment
Waikato in the future management of the aquifers.
The aquifers of Franklin District are important for both the regional and national economies. The area produces one
quarter of the nation’s vegetables, including a large portion that is exported. Irrigation for these crops is supplied
from both groundwater and streams. Most of the streams in the area, the Hingaia, Ngakoroa, Whangapouri, Whangamaire,
Mauku and Waitangi streams, derive most of their flow from groundwater.
“Now we know more about the water sources, Franklin can move forward with confidence,” said Cr Glenn.
To register your interest in getting more information, phone Enviroline on 0800 80 60 40.