Nelson looks to the past to fix '$1m eyesore'
Debate has raged for years over what to do with the weed-infested Tahunanui Modellers Pond in Nelson that's closed due to poor water quality.
Its stagnant summer water has caused such a stink that it's been dubbed a "million-dollar eyesore".
Now, the local council is looking to the past in the hope of finally fixing the algae-plagued pond used by model boat enthusiasts.
Nelson City Council committed this year to spending $1.2 million on retaining and fixing the pond, but detailed costings saw estimates soar past $1.7m and staff recommended exploring other options before reaching a final decision.
An earlier-revoked estuarine option is back on the table after the sport and recreation committee voted on Thursday to put the pond-fix on hold.
*Modellers Pond fix swamped with more than $1.7m in costs
*Councillors cast doubt on $1.2m plan to fix Tahunanui Modellers Pond
*Modellers Pond fix a million-dollar question
*Time running out for pond cleanup
Council staff will spend four to five months developing a detailed business case and exploring a range of sub-options related to the estuarine option. These could range from it to grasslands through to developing a wetland.
Acting chief executive Alec Louverdis said the pond was a complex project because it had provided a vital stormwater function since 1998.
Tahunanui had experienced persistent and regular flooding before then, he said.
"The solutions we'd have come up with back then I think by and large... are the same [as today]," he said.
He said in 1998 several options were considered before the council at that time opted to direct stormwater to the Modellers Pond.
Council staff will now take another look at the other options, but with consideration of current environmental legislation and the Resource Management Act.
Once the detailed business case is complete, councillors will compare it with the $1.73m pond-fix and choose which option to take.
Louverdis said while they had not fully explored the estuarine option, they had already come across complications including varied tide levels.
"We've had many consultants and many advisors looking at this, and it's extremely complex."
To create an estuarine environment would involve a fully notified resource consent, which would involve public consultation.
"The environment we're dealing with now is very different than in 1998," Louverdis said.
A pump station dealing with Tahunanui stormwater would have to cope with "excessive" water flows during heavy rainfall events – an estimated 1.5 cubic metres per second, or as Louverdis put it, "the size of an old VW beetle coming towards you".
A resource consent for an estuarine environment would need to show how the council would mitigate that volume of water.
"Not only from an erosion point of view, but from an aesthetics point of view, and from a water quality point of view."
What councillors had to say
Discussion at previous meetings concentrated on the amenity value of the pond for recreation for Modellers Society members and families, and its position as an icon of Tahunanui.
However, on Thursday the conversation focused on its stormwater function.
Mayor Rachel Reese said some councillors, and members of the public, hadn't understood the issue was not about model boats.
While she didn't like the current amenity of the pond, she said it couldn't be dismissed or just filled in as it was "protecting the homes and businesses of Tahunanui" from flooding.
Cr Brian McGurk said the council had "gone down a rabbit hole" by exploring only the pond fix, instead of considering all options earlier.
The "nostalgic view" of some had hindered the estuarine option being looked at more fully 12 months earlier, he said.
Society of Modellers president Nigel Gibbs said he thought there would be hidden costs in an estuarine scenario.
"Obviously we don't want to see them do that, but I guess they've got to do due diligence and get some costings," Gibbs said.
He said around 50 families belonged to the Modellers Society, but the pond was open to anyone to use.
Gibbs said its weed-infested state meant it had been unusable for some time.
Pondering the options
Modify: Putting a concrete liner on the bottom of the pond, providing sea flushing and yearly maintenance. It would cost $1.73m, and would retain the function of the pond for Modellers Society.
Estuarine: The last estimate had a $690,000 price tag, with a 30 per cent margin of error either side. An updated calculation by staff reached between $1.1m and $1.3m. It could include a grass area or a wetland.
Do Nothing: Not an option due to stormwater. If the pond stays as is, it will need regular cleaning (up to $100,000 annually).