Yellow water lily eradicated in Hawke’s Bay

Hawke’s Bay Regional Council staff surveying Horseshoe Lake in CHB for any remaining yellow water lily.

After 30 years of work, Hawke’s Bay Regional Council has eradicated the invasive pest plant yellow water lily from Hawke’s Bay.

Hawke’s Bay Regional Council biosecurity biodiversity advisor Darin Underhill said a final check of known locations in early January confirmed all traces were gone.

”We started control of yellow water lily in the 90s, so the plant had been around for many years. We started with Horseshoe Lake in Central Hawke’s Bay, half of which was covered in yellow water lilies at the time.

“I sprayed the last piece on this lake in 2009, around 19 years later. I found more growth on a dam nearby, and it was another seven years before that was gone. The last known location was discovered in 2019 and was eradicated two years later in 2021.

The yellow water lily has been eradicated from all known Hawke’s Bay locations, after 30 years of work.

”It’s been a mammoth effort by different teams during the last 30 or so years, and we’re pleased our checks since 2021 have proven the plant has not grown back in any locations.

”This is a huge win for our region as yellow water lily has a negative impact on water and wildlife wherever it grows. It’s dense, spreads quickly, and the large leaves cover water surfaces, blocking sunlight for other plants while changing the habitat for other organisms.

“Yellow water lily can easily choke out any healthy lake, pond, or stream.”

All previously infested areas will be monitored every three years to ensure there is no new growth.

If anyone believes they have found a yellow water lily, contact the Hawke’s Bay Regional Council biosecurity team on (06) 835 9200 or visit hbrc.govt.nz and search #pesthub.