A very large sinkhole has opened up in Auckland's New Lynn after a week of extremely heavy rainfall dumped by a powerful storm centered over the Tasman Sea. The structure of this storm was similar to a tropical cyclone, NIWA said and shared some of the most impressive rainfall records they saw over the past couple of days.
The sinkhole has opened near a major intersection in Auckland's New Lynn, leaving neighboring buildings teetering near the edge. A part of the footpath crumbled away, leaving a sheer drop underground.
The hole is located between the Bike Barn and Club Fia Fia and is as wide as a street. The police have set up caution tape and cordoned off the area.
Officials are still investigating the exact cause and waiting for the water level to drop before further investigations could be carried out safely.
Sinkhole opens in New Lynn, Auckland after heavy rains on March 12, 2017. Credit: @NZGrazie/Twitter
The Tasman Tempest, as the storm was named by NIWA meteorologists, has produced more rain within 5 days that it typically falls for the whole month and caused widespread flooding.
NIWA meteorologist Ben Noll said the storm strengthened off the east coast of Australia a week ago and churned very slowly to the northwest of the North Island over the Tasman Sea for days on end. Warmer than average sea surface temperatures east of Australia contributed to the storm’s strength and duration. In fact, the structure of the Tasman Tempest was similar to a tropical cyclone, he said.
Here are some of the Tasman Tempest's most impressive records, as reported by NIWA:
- Whangamata received 260 mm (10.23 inches) of rain in 24 hours from Tuesday into Wednesday. That was 156% of the normal March rainfall in one day.
- From Tuesday, March 7 to Sunday, March 12, Whangamata recorded 475 mm (18.70 inches) of rainfall, the highest total at any one location from the Tasman Tempest. This was 112% of the normal rainfall for the entire autumn season.
- According to NIWA’s High Intensity Rainfall System, the 225 mm (8.85 inches) that fell in 12 hours on Tuesday night-Wednesday in Upper Hunua exceeded a 1 in 100 year event.
- Between 03:00 and 04:00 NZDT on Saturday, March 11, Kaitaia had its wettest March hour on record (44.6 mm / 1.75 inches ) since hourly records began in 1962.
- Auckland (Mangere) tied its wettest March hour on record with 27.6 mm (1.08 inches) between 17:00 and 18:00 on Friday since hourly records began in 1965.
- Between 09:00 on Friday, March 10 and 09:00 Saturday, March 11, Auckland (Mangere) recorded its wettest March day on record (100 mm / 3.93 inches) since 1959. This was also the 3rd wettest autumn day on record in Auckland (Mangere).
- Hamilton observed its 4th wettest March day on record (since 1907) on the 10th with 77 mm (3.03 inches).
- Kaitaia had its 2nd wettest March day on record (since 1948) on the 10th with 104 mm (4.09 inches).
- With all the rain, Kaitaia is already on track for a top-4 wettest March on record with 216 mm (8.50 inches) since the beginning of the month (267% of the March normal).
- Paraparaumu recorded its 2nd wettest March day on record (since 1951) on the 11th with 74 mm (2.91 inches).
- In the Auckland suburb of New Lynn, it is estimated that 60 mm (2.36 inches) fell in two hours on Sunday afternoon, causing flash flooding. The return frequency on such a rainfall is approximately 1 in 30 years.
- Kumeu recorded 41.4 mm (1.62 inches) of rain in one hour on Sunday, March 12, which is a 1 in 20 year event according to NIWA’s High Intensity Rainfall System.
- Whangaparaoa is on track for its wettest or 2nd wettest March on record since 1948. 226 mm (8.90 inches) have fallen since the 1st of the month, which is 317% of the March normal and 84% of the entire autumn normal.
Featured image: Sinkhole opens in New Lynn, Auckland after heavy rains on March 12, 2017. Credit: @NZGrazie/Twitter