NZ Historic Weather Events Catalogue
August 2002 Gisborne and Hawke's Bay Flooding
(
2002-08-06
)
20-50 year
Torrential rain in the Gisborne area resulted in severe damage and high repair costs.
Gisborne
Heavy Rain
at
Gisborne
Duration: 2 days - Torrential rain caused flooding in Gisborne on the 6th and 7th of August.
Some areas in Gisborne recorded 287 mm (28.7 cm) of rain in 24 hours.
Puninga Road received 405 mm (40.5 cm) of rain in 40 hours (which has return period of 100 years).
The rainfall station at the water supply for the Gisborne district recorded 355 mm (35.5 cm) of rain in 40 hours (which has return period of 80 years).
Flooding
There was surface flooding in Gisborne.
Roads and railway lines were closed. Flooding forced closure of State Highway 2 in several places on the night of the 6th. State Highway 2, between Wairoa and Gisborne, was closed in Matahora Gorge because of surface flooding. Between Te Karaka and Otoko, the highway was down to one lane, with water lapping over a bridge. A number of roads in Gisborne and Poverty Bay areas were also closed late on the afternoon of the 6th. Roads were open on the8th, but the main East Coast railway line was closed for several more days.
Schools around the East Coast closed on the 6th because of flooding and all rural schools around Gisborne closed early on the 5th to ensure buses could get children home.
There was flooding of rural homes.
Stock losses were large.
Homes were evacuated in rural areas.
Flooding and sedimentation was widespread.
Flood damage was described as "Worst than Bola".
Manutuke and the Waingake Valley just south of Gisborne city were especially hard hit.
A motorist had to be rescued from roof of his vehicle after trying to get through a closed, flooded road.
Wharekopae Road was closed.
Floodwaters of up to 30 cm were across one road
Floods caused more than $1,000,000 ($1,213,000 2010 dollars) in fencing damage alone.
Landslide
There were extensive landslides on the coastal hills of the Te Arai catchment and Muriwai.
Slips closed some roads.
Heavy Rain
at
Gisborne city
Gisborne recorded 75 mm (7.5 cm) of rain in 24 hours.
The region surrounding Gisborne received up to 390 mm (39.0 cm) of rain in 36 hours.
Flooding
Some schools in the city closed because of surface flooding.
Gisborne was isolated from Wairoa in the south to Opotiki in the north on morning of the 7th.
60 people in Ngatapa, Papatu, Opou, Manutuke and Taurua Valley areas were evacuated from their homes on the night of the 6th as a precautionary measure against isolation.
Gisborne escaped serious damage on the night of the 6th because of an outgoing tide at the time floodwaters were rising.
Floodwaters started going down around midnight on the 6th.
A couple of houses had water through the basements.
Landslide
The pastured areas of the Gisborne District with slopes over 30 degrees had severe slipping.
Heavy Rain
at
Gisborne Airport
Gisborne Airport recorded 101.8 mm (10.18 cm) of rain in 24 hours.
Heavy Rain
at
Hicks Bay
Hicks Bay recorded 73.6 mm (7.36 cm) of rain in 24 hours.
Flooding
at
Mangatuna
About five homes were evacuated at the small settlement of Mangatuna, near Uawa River.
Flooding
at
Te Karaka
Waipaoa River reached six metres at Te Karaka.
Flooding
at
Uawa River
Uawa River was up to 11 metres on the evening of the 6th.
Hawke's Bay
Heavy Rain
at
Hawke's Bay
There was heavy rainfall in Hawke's Bay on the 6th of August. The rainstorm hit the coast between Mahia and Gisborne.
Rainfall at Hawke's Bay Regional Council sites had a return period of between five and ten years.
Flooding
Roads and railway lines were closed.
Landslide
There were 28 slips and several washouts on the northern part of the main East Coast railway line between Eskdale and Wairoa and more at Kopuawhara.
Heavy Rain
at
Fairview homestead
Fairview station recorded 187 mm (18.7 cm) of rain in 40 hours.
Fairview station recorded 172 mm (17.2 cm) of rain in 24 hours (which has a return period of five years).
Fairview station recorded 124 mm (12.4 cm) of rain in 12 hours (which has a return period of 10 years).
Pukeorapa station recorded 200 mm (20.0 cm) of rain in 40 hours.
Heavy Rain
at
Kopuawhara Stream
In the Gisborne District, which includes the upper Kopuawhara Catchment, 24 hour rainfall totals of over 350 mm (35.0 cm) was recorded (which has a return period of 100 years).
Kopuawhara station recorded 155 mm (15.5 cm) of rain in 40 hours.
Kopuawhara station recorded 142 mm (14.2 cm) of rain in 24 hours (which has a return period of eight years).
Kopuawhara station recorded 95 mm (9.5 cm) of rain in 12 hours (which has a return period of five years).
The derived rainfall for the Kopuawhara catchment was 35.2 mm (35.2 cm )of rain in 36 hours.
The derived rainfall for the Kopuawhara catchment was 339 mm (33.9 cm) of rain in 24 hours.
The derived rainfall for the Kopuawhara catchment was 258 mm (25.8 cm) of rain in 12 hours.
The derived rainfall for the Kopuawhara catchment was 163 mm (16.3 cm) of rain in six hours.
The derived rainfall for the Kopuawhara catchment was 70 mm (7.0 cm) of rain in two hours.
The derived rainfall for the Kopuawhara catchment was 35 mm (3.5 cm) of rain in one hour.
Rainfall records and analysis indicate that the heaviest rainfalls occurred around midnight on the 6th.
Intense rainfall in the upper Kopuawhara Catchment travelled down the valley. Flooding caused considerable damage in the final five kilometres of valley and low lying isthmus at Mahia Peninsula. Kopuawhara Stream overtopped it banks in numerous locations along the lower five kilometres of the valley.
Flooding
There were large amounts of silt and debris deposits. Silt deposition was estimated over 90 percent of the valley floor in the scheme upstream of Mahanga Road. Below Mahanga Road silt covered 55 percent of the scheme.
Banks collapsed in many places due to rapid draw-down.
The flood was assessed to be a 20-50 year event.
Landowners suffered from stock losses, pasture loss and damaged fences.
Pump stations were flooded and road and rail access was affected.
The estimated cost to clear the fallen trees obstructing waterways was $1000 ($1200 2010 dollars).
The estimated cost to repair severe bank erosion threatening existing stopbanks below Mahanga Road was $6600 ($8000 2010 dollars).
The estimated cost to repair severe bank erosion threatening existing stopbanks above Mahanga Road was $6000 ($7300 2010 dollars).
The estimated cost to repair bank erosion due to rapid draw-down was $30,000 ($36,400 2010 dollars).
Landslide
There was significant damage with a range of slip sizes.
Heavy Rain
at
Mahia Peninsula
Mahia Peninsula recorded 88.8 mm (8.88 cm) of rain in 24 hours.
Heavy Rain
at
Napier Airport
Napier Airport recorded 57.6 mm (5.76 cm) of rain in 24 hours.
Heavy Rain
at
Pukeorapa homstead
Pukeorapa station recorded 176 mm (17.6 cm) of rain in 24 hours (which has a return period of five years).
Pukeorapa station recorded 121 mm (12.1 cm) of rain in 12 hours (which has a return period of five years).
References
- Hawke's Bay Regional Council, Kopuawhara Flood Report August 5th-8th 2002, Craig Goodier
- Meteorological Society of New Zealand (Inc.) Newsletter 90, September 2002.
- www.metservice, notable weather events.govt.nz
- Headline: Gisborne flood relief announced.
- www.nzherald.co.nz, Source: NZPA, 23 August 2007.
- Headline: Flood alert on East Coast.
- www.nzherald.co.nz, Source: NZPA, 7 August 2007.
- Headline: Outgoing tide saves Gisborne from serious flooding.
- www.nzherald.co.nz, Source: NZPA, 7 August 2007.
- Headline: Sun shines as Gisborne begins flood clean-up.
- www.nzherald.co.nz, Source: NZPA, 8 August 2007.
August 2002 Gisborne and Hawke's Bay Flooding
(
2002-08-06
)
20-50 year
Torrential rain in the Gisborne area resulted in severe damage and high repair costs.
Gisborne
Heavy Rain
at
Gisborne
Duration: 2 days - Torrential rain caused flooding in Gisborne on the 6th and 7th of August.
Some areas in Gisborne recorded 287 mm (28.7 cm) of rain in 24 hours.
Puninga Road received 405 mm (40.5 cm) of rain in 40 hours (which has return period of 100 years).
The rainfall station at the water supply for the Gisborne district recorded 355 mm (35.5 cm) of rain in 40 hours (which has return period of 80 years).
Flooding
There was surface flooding in Gisborne.
Roads and railway lines were closed. Flooding forced closure of State Highway 2 in several places on the night of the 6th. State Highway 2, between Wairoa and Gisborne, was closed in Matahora Gorge because of surface flooding. Between Te Karaka and Otoko, the highway was down to one lane, with water lapping over a bridge. A number of roads in Gisborne and Poverty Bay areas were also closed late on the afternoon of the 6th. Roads were open on the8th, but the main East Coast railway line was closed for several more days.
Schools around the East Coast closed on the 6th because of flooding and all rural schools around Gisborne closed early on the 5th to ensure buses could get children home.
There was flooding of rural homes.
Stock losses were large.
Homes were evacuated in rural areas.
Flooding and sedimentation was widespread.
Flood damage was described as "Worst than Bola".
Manutuke and the Waingake Valley just south of Gisborne city were especially hard hit.
A motorist had to be rescued from roof of his vehicle after trying to get through a closed, flooded road.
Wharekopae Road was closed.
Floodwaters of up to 30 cm were across one road
Floods caused more than $1,000,000 ($1,213,000 2010 dollars) in fencing damage alone.
Landslide
There were extensive landslides on the coastal hills of the Te Arai catchment and Muriwai.
Slips closed some roads.
Heavy Rain
at
Gisborne city
Gisborne recorded 75 mm (7.5 cm) of rain in 24 hours.
The region surrounding Gisborne received up to 390 mm (39.0 cm) of rain in 36 hours.
Flooding
Some schools in the city closed because of surface flooding.
Gisborne was isolated from Wairoa in the south to Opotiki in the north on morning of the 7th.
60 people in Ngatapa, Papatu, Opou, Manutuke and Taurua Valley areas were evacuated from their homes on the night of the 6th as a precautionary measure against isolation.
Gisborne escaped serious damage on the night of the 6th because of an outgoing tide at the time floodwaters were rising.
Floodwaters started going down around midnight on the 6th.
A couple of houses had water through the basements.
Landslide
The pastured areas of the Gisborne District with slopes over 30 degrees had severe slipping.
Heavy Rain
at
Gisborne Airport
Gisborne Airport recorded 101.8 mm (10.18 cm) of rain in 24 hours.
Heavy Rain
at
Hicks Bay
Hicks Bay recorded 73.6 mm (7.36 cm) of rain in 24 hours.
Flooding
at
Mangatuna
About five homes were evacuated at the small settlement of Mangatuna, near Uawa River.
Flooding
at
Te Karaka
Waipaoa River reached six metres at Te Karaka.
Flooding
at
Uawa River
Uawa River was up to 11 metres on the evening of the 6th.
Hawke's Bay
Heavy Rain
at
Hawke's Bay
There was heavy rainfall in Hawke's Bay on the 6th of August. The rainstorm hit the coast between Mahia and Gisborne.
Rainfall at Hawke's Bay Regional Council sites had a return period of between five and ten years.
Flooding
Roads and railway lines were closed.
Landslide
There were 28 slips and several washouts on the northern part of the main East Coast railway line between Eskdale and Wairoa and more at Kopuawhara.
Heavy Rain
at
Fairview homestead
Fairview station recorded 187 mm (18.7 cm) of rain in 40 hours.
Fairview station recorded 172 mm (17.2 cm) of rain in 24 hours (which has a return period of five years).
Fairview station recorded 124 mm (12.4 cm) of rain in 12 hours (which has a return period of 10 years).
Pukeorapa station recorded 200 mm (20.0 cm) of rain in 40 hours.
Heavy Rain
at
Kopuawhara Stream
In the Gisborne District, which includes the upper Kopuawhara Catchment, 24 hour rainfall totals of over 350 mm (35.0 cm) was recorded (which has a return period of 100 years).
Kopuawhara station recorded 155 mm (15.5 cm) of rain in 40 hours.
Kopuawhara station recorded 142 mm (14.2 cm) of rain in 24 hours (which has a return period of eight years).
Kopuawhara station recorded 95 mm (9.5 cm) of rain in 12 hours (which has a return period of five years).
The derived rainfall for the Kopuawhara catchment was 35.2 mm (35.2 cm )of rain in 36 hours.
The derived rainfall for the Kopuawhara catchment was 339 mm (33.9 cm) of rain in 24 hours.
The derived rainfall for the Kopuawhara catchment was 258 mm (25.8 cm) of rain in 12 hours.
The derived rainfall for the Kopuawhara catchment was 163 mm (16.3 cm) of rain in six hours.
The derived rainfall for the Kopuawhara catchment was 70 mm (7.0 cm) of rain in two hours.
The derived rainfall for the Kopuawhara catchment was 35 mm (3.5 cm) of rain in one hour.
Rainfall records and analysis indicate that the heaviest rainfalls occurred around midnight on the 6th.
Intense rainfall in the upper Kopuawhara Catchment travelled down the valley. Flooding caused considerable damage in the final five kilometres of valley and low lying isthmus at Mahia Peninsula. Kopuawhara Stream overtopped it banks in numerous locations along the lower five kilometres of the valley.
Flooding
There were large amounts of silt and debris deposits. Silt deposition was estimated over 90 percent of the valley floor in the scheme upstream of Mahanga Road. Below Mahanga Road silt covered 55 percent of the scheme.
Banks collapsed in many places due to rapid draw-down.
The flood was assessed to be a 20-50 year event.
Landowners suffered from stock losses, pasture loss and damaged fences.
Pump stations were flooded and road and rail access was affected.
The estimated cost to clear the fallen trees obstructing waterways was $1000 ($1200 2010 dollars).
The estimated cost to repair severe bank erosion threatening existing stopbanks below Mahanga Road was $6600 ($8000 2010 dollars).
The estimated cost to repair severe bank erosion threatening existing stopbanks above Mahanga Road was $6000 ($7300 2010 dollars).
The estimated cost to repair bank erosion due to rapid draw-down was $30,000 ($36,400 2010 dollars).
Landslide
There was significant damage with a range of slip sizes.
Heavy Rain
at
Mahia Peninsula
Mahia Peninsula recorded 88.8 mm (8.88 cm) of rain in 24 hours.
Heavy Rain
at
Napier Airport
Napier Airport recorded 57.6 mm (5.76 cm) of rain in 24 hours.
Heavy Rain
at
Pukeorapa homstead
Pukeorapa station recorded 176 mm (17.6 cm) of rain in 24 hours (which has a return period of five years).
Pukeorapa station recorded 121 mm (12.1 cm) of rain in 12 hours (which has a return period of five years).
References
- Hawke's Bay Regional Council, Kopuawhara Flood Report August 5th-8th 2002, Craig Goodier
- Meteorological Society of New Zealand (Inc.) Newsletter 90, September 2002.
- www.metservice, notable weather events.govt.nz
- Headline: Gisborne flood relief announced.
- www.nzherald.co.nz, Source: NZPA, 23 August 2007.
- Headline: Flood alert on East Coast.
- www.nzherald.co.nz, Source: NZPA, 7 August 2007.
- Headline: Outgoing tide saves Gisborne from serious flooding.
- www.nzherald.co.nz, Source: NZPA, 7 August 2007.
- Headline: Sun shines as Gisborne begins flood clean-up.
- www.nzherald.co.nz, Source: NZPA, 8 August 2007.