Gisborne might face drought

Water restrictions limit sprinklers and hoses.

Water restrictions limit sprinklers and hoses.

The soil moisture deficit for Gisborne has passed 145mm, the danger mark for previous drought years.
FALLING: The cloud of dust following this tractor is an indication of how dry the ground has become in the Gisborne district, with no significant rainfall since November. Picture by Roger Handford

THE CONTINUING hot dry weather has the district facing the prospect of drought.

On Monday the Gisborne District Council issued its first water restriction alert to farmers in the Te Arai catchment.

Yesterday the council started water restrictions in the city, asking people to limit sprinkler use to between 6am and 8am and to keep hand-held hosing to a minimum.

Gisborne District Council water team leader Marcus Koll says three days of continued high temperatures and high outdoor water usage has taken its toll on city reservoir storage levels.

“The amount of water being used spiked to 27,600 cubic metres during yesterday’s hot temperatures, which is extremely high."

The extended Metservice weather forecast suggests continued high temperatures over the next 10 days.

Hosing restrictions have been introduced because city storage reservoirs are approaching levels reserved for emergency storage, Mr Koll said.

“Operationally, we are at maximum flows into the city without over-pressuring the city, which if exceeded, could result in water mains breaks.”

The Mangapoike dams are currently around the normal storage levels for this time of year but they are receding fast, he said.

Monitoring the dry

Monitoring of the drying by various agencies indicates the region is on the edge of drought. Yesterday the soil moisture deficit for Gisborne passed 145mm, and the record shows that this is the danger mark for previous drought years.

As of yesterday morning the loss of moisture from the soil — evapotranspiration — has soared to a daily average of 5.7mm over the past week, and yesterday’s 33-degree scorcher will have pushed that over 6mm.

Grass and scrub has reached tinder-dry levels with the run of hot dry weather, and rivers and stream levels around the district have dropped with the lack of any decent rain.

The dry conditions have meant a total fire ban has been in place for the whole district since Christmas.

Water carriers to homes relying on tank water supply say the increased demand is akin to being in a drought, although people don’t realise it because of the cooler temperatures.

“It has been a long, sustained dry period but without the intense heat,” said John Allison of John Allison Contracting.

Greg Hall from Gisborne District Council’s hydrological monitoring section said “It’s right on the edge of a drought”, and with little significant rain predicted in the near future, “it is worrying”.

“All the rivers and streams are getting low, and the council is keeping a close watch on the situation.”

First-level alert

A first-level alert has been notified to farmers taking water in the Te Arai catchment, that the flow in the stream has dropped to 54 litres a second.

This means they now have to reduce their take to 40 percent of their daily permitted total.

On the Gisborne Flats, irrigation is yet to hit full swing, and Mr Hall said while some crops are retarded because of the lack of moisture, irrigators are not using as much as the same time last year, and are being very careful about water use.

Daily climate maps produced by the National Institute of Water and Atmospheric Research (Niwa) show it is drier than last year, and drier than average for the time of year.

Analysis of the past 26 years’ rainfall figures shows the dry period to date is even drier than the severe 1997-98 El Nino drought, and the drought of 2008.

Soil moisture levels are in the red along the coastal strip to East Cape, with the Gisborne Flats and Mahia also in the red, with soil deficits well over 130mm.

There has been just a touch of rain this month: 3.6mm against the MetService average of 56mm for Gisborne over January.

Dry since November

The current dry period started in November, with that month recording just 11.6mm. December did not help, with 27.6mm, less than half that month’s usual rainfall.

The only rain forecast by MetService in the next 10 days amounts to nothing more than a few light showers.

Niwa data shows the 30-year average rainfall for November, December and January is around 180mm, so the current soil moisture deficit accurately pinpoints the missing 145-plus millimetres.

Niwa’s latest three-monthly climate forecast says temperatures are equally likely to be above average (45 percent chance) or near average (40 percent chance), while rainfall totals, river levels and soil moisture are equally likely to be in the near normal (40 percent chance) or below normal (40 percent chance) range.

Soil moisture levels at council monitoring sites have plummeted. At the Cameron Road site, soil moisture stood at less than five percent.

Similarly on the sandy soil at Tatapouri, the level stands at just 10 percent.

On the inland sites at Tauwhare and Puketawa stations, the soil moisture levels are at 20 percent.

Sunny, dry weather and high temperatures are forecast by MetService to continue to Sunday, with the mercury expected to go to 30 degrees or more today and tomorrow.

Next Monday might bring some rain, but it is not expected to amount to much.

Council planning for any drought this year includes starting to take water from the Waipaoa River through the Waipaoa Water Augmentation plant earlier than in the past, before the town reservoir levels start to drop.

The council intends to keep the reservoir levels high to maintain pressure, while using the Waipaoa Augmentation plant to make up any shortfall.

For rural users, the strategy this year is for a more staged reduction in takes rather than an all-or-nothing drastic reduction or cut-off.

—Additional reporting Gisborne Herald staff reporters

THE CONTINUING hot dry weather has the district facing the prospect of drought.

On Monday the Gisborne District Council issued its first water restriction alert to farmers in the Te Arai catchment.

Yesterday the council started water restrictions in the city, asking people to limit sprinkler use to between 6am and 8am and to keep hand-held hosing to a minimum.

Gisborne District Council water team leader Marcus Koll says three days of continued high temperatures and high outdoor water usage has taken its toll on city reservoir storage levels.

“The amount of water being used spiked to 27,600 cubic metres during yesterday’s hot temperatures, which is extremely high."

The extended Metservice weather forecast suggests continued high temperatures over the next 10 days.

Hosing restrictions have been introduced because city storage reservoirs are approaching levels reserved for emergency storage, Mr Koll said.

“Operationally, we are at maximum flows into the city without over-pressuring the city, which if exceeded, could result in water mains breaks.”

The Mangapoike dams are currently around the normal storage levels for this time of year but they are receding fast, he said.

Monitoring the dry

Monitoring of the drying by various agencies indicates the region is on the edge of drought. Yesterday the soil moisture deficit for Gisborne passed 145mm, and the record shows that this is the danger mark for previous drought years.

As of yesterday morning the loss of moisture from the soil — evapotranspiration — has soared to a daily average of 5.7mm over the past week, and yesterday’s 33-degree scorcher will have pushed that over 6mm.

Grass and scrub has reached tinder-dry levels with the run of hot dry weather, and rivers and stream levels around the district have dropped with the lack of any decent rain.

The dry conditions have meant a total fire ban has been in place for the whole district since Christmas.

Water carriers to homes relying on tank water supply say the increased demand is akin to being in a drought, although people don’t realise it because of the cooler temperatures.

“It has been a long, sustained dry period but without the intense heat,” said John Allison of John Allison Contracting.

Greg Hall from Gisborne District Council’s hydrological monitoring section said “It’s right on the edge of a drought”, and with little significant rain predicted in the near future, “it is worrying”.

“All the rivers and streams are getting low, and the council is keeping a close watch on the situation.”

First-level alert

A first-level alert has been notified to farmers taking water in the Te Arai catchment, that the flow in the stream has dropped to 54 litres a second.

This means they now have to reduce their take to 40 percent of their daily permitted total.

On the Gisborne Flats, irrigation is yet to hit full swing, and Mr Hall said while some crops are retarded because of the lack of moisture, irrigators are not using as much as the same time last year, and are being very careful about water use.

Daily climate maps produced by the National Institute of Water and Atmospheric Research (Niwa) show it is drier than last year, and drier than average for the time of year.

Analysis of the past 26 years’ rainfall figures shows the dry period to date is even drier than the severe 1997-98 El Nino drought, and the drought of 2008.

Soil moisture levels are in the red along the coastal strip to East Cape, with the Gisborne Flats and Mahia also in the red, with soil deficits well over 130mm.

There has been just a touch of rain this month: 3.6mm against the MetService average of 56mm for Gisborne over January.

Dry since November

The current dry period started in November, with that month recording just 11.6mm. December did not help, with 27.6mm, less than half that month’s usual rainfall.

The only rain forecast by MetService in the next 10 days amounts to nothing more than a few light showers.

Niwa data shows the 30-year average rainfall for November, December and January is around 180mm, so the current soil moisture deficit accurately pinpoints the missing 145-plus millimetres.

Niwa’s latest three-monthly climate forecast says temperatures are equally likely to be above average (45 percent chance) or near average (40 percent chance), while rainfall totals, river levels and soil moisture are equally likely to be in the near normal (40 percent chance) or below normal (40 percent chance) range.

Soil moisture levels at council monitoring sites have plummeted. At the Cameron Road site, soil moisture stood at less than five percent.

Similarly on the sandy soil at Tatapouri, the level stands at just 10 percent.

On the inland sites at Tauwhare and Puketawa stations, the soil moisture levels are at 20 percent.

Sunny, dry weather and high temperatures are forecast by MetService to continue to Sunday, with the mercury expected to go to 30 degrees or more today and tomorrow.

Next Monday might bring some rain, but it is not expected to amount to much.

Council planning for any drought this year includes starting to take water from the Waipaoa River through the Waipaoa Water Augmentation plant earlier than in the past, before the town reservoir levels start to drop.

The council intends to keep the reservoir levels high to maintain pressure, while using the Waipaoa Augmentation plant to make up any shortfall.

For rural users, the strategy this year is for a more staged reduction in takes rather than an all-or-nothing drastic reduction or cut-off.

—Additional reporting Gisborne Herald staff reporters

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DOUG CURTIS - 3 months ago
The old WAIKOHU Railway station is looking sad and neglected these days. Brings back memories of the car-rail bridge nearby, now long gone.

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