Storage ponds a ‘ludicrous’ alternative to Dam

Claims about storage ponds being a viable alternative to the Waimea Community Dam are ludicrous, says Waimea Irrigators Limited (WIL) Chair Murray King.

“There are many reasons storage ponds won’t solve the region’s water problem, including insufficient capacity, ponds not addressing the minimum flow requirements on the Waimea River, and the lack of funding available for them.

“The idea is utterly ludicrous. A combined storage volume of 6 million cubic metres of water won’t meet the minimum flow requirements set out in the Tasman Resource Management Plan (TRMP) and provide adequate water for water users in dry periods. The minimum flows were established through an Environment Court process so the Council can give effect to the National Policy Statement for Freshwater Management.

“Replenishment of water in the storage ponds would only be possible during periods of high flow. Once the water was drawn from the ponds during a dry spell, there would be no more water available for replenishment until the next sizeable ‘fresh’ in the river, meaning that urban and rural water users would once again be facing severe water restrictions.”

Mr King challenges any suggestion that three ponds could be constructed for a total amount of $40 million. An Irrigation New Zealand spokesperson says the current build price in Canterbury for a 4m high storage pond is $8 per cubic metre of water, or $48 million for 6 million cubic metres. Due to the amount of dirt that has to be shifted and stringent dam safety requirements the price escalates quickly over 4m; an 8m high storage pond could be closer to $100 million to construct.

He says another key reason the storage ponds idea won’t work is that no one is stepping up to fund them like they are the Waimea Community Dam.

“The Dam has $59.12 million from non-Council funders. None of these will pay for storage ponds.”

This funding, from loan, grant or equity, is:

  • Crown Irrigation Investments Limited (CIIL) loan funding – $22.12 million to WIL
  • CIIL loan funding – $10.0 million to Council
  • Waimea Irrigators Ltd equity funding – $15.0 million
  • Ministry for the Environment grant funding – $7.0 million
  • Nelson City Council equity funding – $5.0 million

CIIL CEO Murray Gribben says it is wrong to suggest funding currently committed to the Waimea Community Dam would be available for other water storage options.

“The term sheet, the concessionary nature of the terms and the quantum of funding set out were based on the Waimea Community Dam as currently contemplated, including the level of economic and environmental benefits it is expected to generate. CIIL funding is not designed to support urban water needs.”

Without the Dam, larger irrigators will be forced to find other solutions, none of which solve the need for more water for urban residents, who will be on rations nine years out of 10 based on historic river flows.

Mr King says, “The bigger guys will look to put in their own storage ponds, which will mean instead of having a community solution, irrigators and the council will end up competing with one another for water.

“The cost to irrigators to construct on-farm storage will be more than four times what they are currently contributing to the Dam. If you add the consenting costs and the opportunity cost of the loss of productive land then the figures are even worse.

“Land owners with just a few hectares will be on their own basically, because they won’t have room for storage ponds. The situation for them is dire if their businesses rely on water. The loss of productivity on irrigators land will affect the whole district.”