The eel population in Masterton's Homebush sewerage ponds will have a bit of a push to their new home when the multi-million dollar upgrade is complete - at a cost of up to $35,000.
Masterton District Council officers have recommended a number of options to help the estimated 85,000 eels transfer to the new ponds, according to a report to be discussed at the policy and finance committee meeting today.
This includes installing an eel ladder, or coarse matting, and a connecting pipe between the ponds, and a fall-back option of trapping and transferring the eels, potentially to an entirely new location if the new ponds are an unsuitable environment.
The costs range from estimates of $12,000 to $35,000.
Assets and operations manager David Hopman said it was a joint initiative between local iwi Ngati Kahungunu ki Wairarapa and Rangitane o Wairarapa and council.
"Council recognised that the eel population within the ponds needed to be managed during the upgrade," he said.
"Iwi are also concerned about the tuna [eels], recognising that they are a significant population, contributing through reproduction to the greater population of eels within New Zealand."
Mr Hopman said the eels have found their own way into the ponds and their position on the top of the food chain indicates the eco-system that makes up the treatment process is working well.
Kahungunu is looking into the Ministry of Environment's Fresh Start for Fresh Water Fund to contribute to some of the more expensive ideas if necessary.
Mr Hopman will work through the funding application process with iwi and believes funding can be secured if required. He said experience from previous treatment pond decommissionings has shown that eels find their own way into new environments when the food supply reduces.
Mr Hopman said the inflows will be diverted to the new ponds in April and the work to install the pipeline will start soon after.
The new ponds will take approximately four to six weeks to fill, and once filled, the transfer pipeline will be commissioned and water will flow from the new to the old pipelines and create the scent trail.
The recommendations will go to councillors at the meeting this afternoon.