"The hole is well cordoned off by fencing, but if you were to fall into it you could seriously injure yourself."
Last week more than 300 homes were flooded with waist-deep water after a huge rain storm.
The torrential rain, including 65mm in just one hour, also covered backyards with raw sewage.
Some residents said it took just 15 minutes to flood their homes and turn streets into rivers as so much rain fells so quickly.
This weekend is shaping up to be mainly fine around the country - a welcome relief after last week's deluge and downpours.
A small ridge would bring rain, first to the south of the South Island tonight before travelling north towards the East Coast of the North Island.
However the front would weaken as it moved, meaning it would only bring light, patchy showers to most areas, said MetService meteorologist Philippa Murdoch.
"We've got fairly settled weather with a ridge over the country."
The forecast would be welcome relief to those caught in last weekend's downpour, which saw a month's worth of rain fall in one day across Auckland and Coromandel.
The week of wet weather caused havoc in parts of the North Island, with flooding in the Coromandel getting so bad last Saturday the army had to be called in to help evacuate a festival.
The waterlogged peninsula was set to get a reprieve however, with "just a few little light showers up in the north today" clearing out to make way for a dry weekend.
Early cloud is forecast for Auckland tomorrow but the rest of the weekend should be fine and it was the same story in most other places around the country.
"By the end of Sunday it looks like most of the country has cleared," Murdoch said.
"Mostly fine, just a few cloudy areas."
Showers and a southerly were in store for Wellington on Saturday but again the rain would be light and clearing over the weekend, Murdoch said.
Today's forecast
•Whangarei: Cloudy periods, chance shower. Southeasterlies. 22C
•Auckland: A fine day with light winds and sea breezes. 24C
•Hamilton: A fine day. Light winds. 24C
•Tauranga: A fine day, light winds and sea breezes. 22C
•Wellington: Mainly fine, some evening cloud. Northerlies strengthening. 20C
•Christchurch: Fine. Northerly turns westerly afternoon. 28C