May_2010_Tasman-Nelson_Flooding May 2010 Tasman-Nelson Flooding 2010-05-14 Moderate There were thunderstorms across New Zealand and a tornado in Taranaki which caused some damage. Tasman-Nelson was hit with heavy rain which caused flooding in the Tapawera area. 22 households were evacuated. Thunderstorms, heavy rain and fooding affected New Zealand from the 14th to the 16th of May 2010. MetService SEVERE THUNDERSTORM WATCH was issued at 04:52 pm Friday 14 May 2010 for Northland, Auckland, Great Barrier Island, Coromandel Peninsula, Waikato and Bay of Plenty. A very unstable airmass lay over the upper North Island. MetService SEVERE WEATHER WARNING was issued at 19:23 pm 14-May-2010: Heavy rain and thunderstorms at times through the weekend for Bay of Plenty, Mt Taranaki, Nelson and northern parts of Marlborough. A large complex low over the Tasman Sea contains several bands of heavy showers and thunderstorms. MetService SEVERE THUNDERSTORM WATCH was issued at 05:01 am Saturday 15 May 2010 for Northland, Auckland, Great Barrier Island, Coromandel Peninsula, Waikato, Bay of Plenty, Rotorua and Gisborne. A very unstable airmass lay over the upper North Island. MetService SEVERE THUNDERSTORM WATCH was issued at 05:50 am Saturday 15 May 2010 for Northland, Auckland, Great Barrier Island, Coromandel Peninsula, Waikato, Bay of Plenty, Rotorua and Gisborne. The thunderstorms are expected to affect mostly northeastern coasts, and some may be SEVERE. These thunderstorms have the potential to produce brief heavy rain, hail of 15-20mm+ diameter, and there is a risk of a damaging tornado, particularly between the eastern Northland coast and northern Coromandel Peninsula. MetService SEVERE WEATHER WARNING was issued at 07:48 am 15-May-2010: Heavy rain and thunderstorms at times through the weekend for Bay of Plenty, the far north of Gisborne, Mt Taranaki, Nelson and northern parts of Marlborough. A large complex low over the Tasman Sea contains several bands of heavy showers and thunderstorms. MetService SEVERE THUNDERSTORM WATCH was issued at 12:20 pm Saturday 15 May 2010 for Waitomo, Taumarunui and Taranaki. An active trough is expected to move across Taranaki and coastal Waitomo this afternoon and early evening. Thunderstorms are expected with this trough, with a possibly of SEVERE storms. MetService SEVERE THUNDERSTORM WATCH was issued at 04:20 pm Saturday 15 May 2010 for Bay of Plenty, Rotorua and Gisborne. A band of heavy rain and squally thunderstorms is moving eastwards over Bay of Plenty this afternoon and evening. MetService SEVERE WEATHER WARNING was issued at 20:43 pm 15-May-2010: Heavy rain and thunderstorms at times through the weekend for Bay of Plenty, the far north of Gisborne, Mt Taranaki, Nelson and northern parts of Marlborough. A large complex low over the Tasman Sea contains several bands of heavy showers and thunderstorms. These convective rainbands are expected to spiral around the low and sweep onto the North Island and upper South Island. MetService SEVERE WEATHER WARNING was issued at 08:37 am 16-May-2010: Further heavy showers and thunderstorms at times today for Bay of Plenty, the far north of Gisborne, Mt Taranaki, Nelson and northern parts of Marlborough. A large complex low is slow-moving west of Nelson. Further bands of heavy showers and thunderstorms circulating around the low are expected to cross northern and central New Zealand today. MetService SEVERE WEATHER WARNING was issued at 20:51 pm 16-May-2010: Heavy rain easing overnight. A large complex low centred west of Buller is expected to weaken and move away to the northwest overnight and Monday morning. The heavy rain that has affected a number of areas is expected to ease overnight. MetService SEVERE WEATHER WARNING was issued at 07:58 am 17-May-2010: Heavy rain has eased. The heavy rain affecting parts of Bay of Plenty, the far north of Gisborne,Nelson and Marlborough has now eased and the warnings are now lifted. More than a month's rain fell in 12 hours in the upper South Island. The province was struck by wet and windy weather from the 14th to the 16th May 2010. The heavy rain caused surface flooding around the region but there were no reports of serious damage. Wet conditions caused cars to slide from roads. -39.051214 174.06972 New Plymouth recorded 71 mm (7.1 cm) of rain in 48 hours to 2pm on the 16th. The New Plymouth Fire Brigade was called to Starbucks at 9am on the 16th after water got in to the roof and caused part of the ceiling to collapse. -39.115805 173.953382 A Taranaki woman, Melva Benton, had to cling to a farm gate as a tornado hurtled towards her near Oakura on the night of the 14th. The twister had come from nearby Plymouth Road where it dropped a tree and demolished a hayshed. The tornado flatted a large pine shelter belt on the Benton farm, took the roof off a wood shed and destroyed a tractor shed. Mrs Benton suffered a bruised back. Before the twister appeared there was heavy rain, thunder and lightning in the area. -39.321582 174.105391 Dawson Falls recorded 186 mm (18.6 cm) of rain in 48 hours to 2pm on the 16th. -39.269979 174.085413 North Egmont recorded 166 mm (16.6 cm) of rain in 48 hours to 2pm on the 16th. The weather came from a low-pressure system in the Tasman Sea, which had curved slowly to the east then southeast towards Farewell Spit on the evening of the 14th. Stormy weather caused power cuts in Motueka and Moutere on the night of the 14th. 300 kilometres of road was affeced by the heavy rain. Sherry River Road was closed near the top end due to flooding at a culvert and washing out. There was a lot of damage to roads, bridges and culverts in the Waimea catchment. The Kaiteriteri loop and Riwaka Valley had minor slips. -41.268476 173.297338 Nelson's drought was ended with a overnight of the 14th with a cloudbust which dumped close to the combined March and April rainfall in one day. Nelson recorded 58 mm (5.8 cm) of rain in 24 hours to 9am on the 15th. Nelson recorded 40 mm (4.0 cm) of rain in 21 hours from 9am on the 14th to 6am on the 15th. Nelson recorded 23 mm (2.3 cm) of rain in 45 minutes overnight of the 14th. -41.338974 173.165031 Richmond recorded 40 mm (4.0 cm) of rain in 24 hours to 9am on the 15th. -40.854005 172.800335 Takaka recorded 18.5 mm (1.85 cm) of rain in 24 hours to 9am on the 15th. -41.10406 173.020407 Motueka recorded only 5 mm (0.5 cm) of rain in 24 hours to 8:45am on the 15th. -41.31689 173.2333 Stock took the brunt of the heavy rain. The floor of the New World supermarket in Neale Ave was flooded with a couple of centimetres of water at 9pm on the 14th. A property in Bledisloe Ave had minor flooding in the garage. Power was cut to nearly 1000 Stoke consumers at 1am on the 15th and restored three hours later. -40.513247 172.846751 Farewell Spit recorded 30 mm (3.0 cm) of rain between 6am and 8am on the 15th. -41.385310 172.823799 Tapawera recorded 100 mm (10.0 cm) of rain in 12 hours until 1pm on the 16th. Between 10 and 20 households were left isolated by the flooding in Tapawera, south-west of Nelson. They remained isolated for up to three days. Residents of 22 homes were evacuated (13 by helicopter). Roads were washed out by mud and logs. A family living on the Motueka River near Tapawera had a flash-flood go through their house and were rescued by helicopter. A family woke to find the stream by their home on Tapawera Baton Road a torrent of muddy water and logs. The water quickly surrounded their home. Dovedale residents were urged to conserve water for 24 hours following the flood as debris affected the intake to their water scheme. Civil Defence set up an emergency station at the Tapawera rugby club rooms. One house was destroyed. Rivers broke their banks. Tapawera Baton Road was blocked between Twin Bridges. There was surface flooding on sections of the Tapawera Road. A farm at West Bank Road at Wangapeka had thousands of logs crashing down the hills behind their place. The wall of logs wiped out three sheds, a car, two power generation systems and their chickens and turkeys. Another farm lost their water tanks and fences and would need a digger to clear the piles of log debris from the back of their house on Tapawera Baton Road. Big, heavy logs were left lying across farm properties, fences were down and flooded homes were carpeted in muddy silt. Flooding threatened power poles beside Tapawera Baton Road and eight properties lost power on the 16th but it was restored before 9pm. Mud slides brought down logs with them, some of which had taken out sheds, vehicles, fences and one had flowed through a house. Residents blamed forestry practices that left harvested logs and debris on the ground that could be washed away in heavy rain and floods then form dams which bursts sending an avalanche of logs downstream. It was the third time in 21 years that it had happened. Baton Valley Road was closed early on the 16th due to a slip but was reopened at 4pm. -41.10406 173.020407 Nelson Bays Police and Civil Defence were asking people not to attempt to travel through the Motueka Valley. Peach Island in Motueka was surrounded by water when the Motueka River spilles onto its secondary flow channel along West Bank Road before rejoining the main river at Kayak Corner. A Motueka resident Avrill Nicoll said she had only ever seen the Motueka River this high once before in her five years living by the river. Motueka Valley Highway had a manned road closure at Woodstock turnoff through to Tapawera and there were many sites where water and debris had gone across the road. The road was still passable on one lane. Motueka Highway was blocked by a slip at McLeans Reserve, 30 km from Lower Motueka Valley. Motueka West bank had several minor slips. -41.28189 172.76109 It was the fourth largest flood on record for the Baton River which received between 13 mm and 17 mm (1.3-1.7 cm) of rain in a 15 minute period. -41.3167 172.7833 There was 122 mm (12.2 cm) of rain in the Wangapeka River on the 16th. There were reports of logs entering the Wangapeka River which will travel down the Motueka River. River users, such as kayakers, were advised to keep out of the river. -40.940021 172.81314 Lindsays Bridge alarm was activated mid afternoon on the 16th, however waters started to recede quickly after this point. -40.879202 172.791362 Lightning cut power to 58 properties in the Kotinga area on the afternoon of the 14th. Two household were without power until the 15th. A small tornado blew a shed roof through power lines supplying electricity to a farm. Media Release from Nelson Tasman Civil Defence Group, 16 May 2010. Tapawera Flooding: Number 1 Reference Media Release from Nelson Tasman Civil Defence Group, 16 May 2010. Tapawera Flooding: Number 2 Reference Media Release from Nelson Tasman Civil Defence Group, 16 May 2010. Tapawera Flooding: Number 3 Reference Media Release from Nelson Tasman Civil Defence Group, 16 May 2010. Tapawera Flooding: Number 4 Reference Media Release from Nelson Tasman Civil Defence Group, 17 May 2010. Tapawera Flooding: Number 5 Reference MetService Email Lists Reference Headline: Dry spell's dramatic end. Reference www.stuff.co.nz, 15 May 2010, 12:30pm. Headline: Floods isolate families in Nelson. Reference www.stuff.co.nz, 16 May 2010, 6:30pm. Headline: Log avalanche as flood hits. Reference www.stuff.co.nz, 17 May 2010, 1:00pm. Headline: Residents airlifted from flooded homes. Reference www.stuff.co.nz, 17 May 2010, 5:00am. Headline: Woman clings on for her life as tornado hits. Reference www.stuff.co.nz, 17 May 2010, 5:00am. Headline: Downpour 'trashes' properties. Reference www.stuff.co.nz, Source: The Nelson Mail, 17 May 2010, 1:00pm. Headline: Tornado cuts power. Reference www.stuff.co.nz, Source: The Nelson Mail, 17 May 2010, 1:00pm.