Flood risk higher with Otago off the radar

Kate Wilson
Kate Wilson
The Taieri and other flood-prone catchments are at risk by not having an effective rain warning system, Dunedin City councillor and Middlemarch farmer Kate Wilson says.

Rain radars provide up to 90 minutes' notice of severe thunderstorms, detect pockets of heavy rain and produce high-resolution rainfall analyses for flood and catchment monitoring.

The closest radars are in Invercargill and Rakaia, Canterbury.

Without radar, forecasters have less comprehensive information about approaching rainstorms than they do in other regions.

Cr Wilson said from a farmer's perspective, let alone a civil defence one, it was frustrating not to have more certainty about rainfall predictions.

''Certain areas do not get a lot of notice.''

Given the technology was available, the risk factor and the economic benefit of having more detailed rainfall information, Dunedin and Otago should have a radar, she said.

''Our Government should fund one, as that is what it does in other areas,'' she said.

Cr Wilson had raised the issue at a recent members of Parliament forum and would be calling on community boards and other Otago councils to write in support of a radar.

''It's bizarre we do not have one in such a highly populated area.''

Otago Regional Council chairman Stephen Woodhead said he supported the push as a rain radar would be very helpful, particularly in short catchments such as the Silverstream, on the Taieri, and the Water of Leith in Dunedin.

''These can quickly flood with not much time to react.''

That meant regional council staff and the community had little time to warn or plan for major events.

''It would be extremely helpful for our work with hazards and flooding.''

A MetService spokeswoman said the only reason a radar had not been installed was the cost. MetService had a commercial contract with the Ministry of Transport and a radar for Otago was included in the weather service's 2012 and 2009 proposals to it.

''MetService ... is very supportive of the provision of severe weather warnings for Otago as a high priority service.''

A weather radar covering Dunedin city and Otago was likely to cost about $2.5 million to $3 million and take up to two years to establish.

Another option, for about a quarter of the cost, could be to move the Invercargill radar at the end of next year when it became surplus to balloon-tracking requirements, but it would be an older technology solution without dual-polarisation capability, she said.

National list MP Michael Woodhouse, of Dunedin, said what was important was not where the rain radar was located but whether the area was getting accurate information from it.

''I'm not aware that there is any problem with the information we are currently receiving.''

A Ministry of Transport spokesman said prioritisation of the rain radar's implementation was ultimately MetService's decision. It had installed five in the North Island in the past few years.

The global financial crisis meant MetService's funding was frozen for three years due to the Government's expectation of efficiencies.

In the last Budget, MetService received an extra $1.2 million, bringing its contract to $20.1 million.

''The one-off additional payment was made on the understanding that MetService is currently renegotiating its contract to provide forecasting services.''

Dunedin Labour MP Clare Curran said she was astounded the cost of a radar had been the casualty of the Government's funding freeze which had yet again left Otago ill-served.

-rebecca.fox@odt.co.nz


Additional weather radars
• Taranaki 2007-08
• Gisborne2008-09
• BoP 2009-10
• West Coast 2011-12
• Far North 2012-13

Source: Ministry of Transport


Rain radar

Radar waves travel in straight lines, so precipitation originating at lower altitudes isn't picked up very well by distant stations because of intervening hills and the curvature of the earth.

Otago Radar

But... if you look at the Southland radar with any frequency at all (as I suspect most farmers, ranchers, fishermen, etc. do) you'd realise that the Southland radar is off line about half of the time. Why this radar is down so frequently is a mystery to me, and after repeated inquiries, it's apparently also a mystery to the Metservice. Dunedin is at the very edge of the Canterbury radar, so when the Southland radar goes down, it's impossible to see the storms coming from the south. We are not well served by this arrangement at all, and the National government seems to think that serving the interests of the 1% is more important than providing reliable storm forecasting for Otago. Once again, Dunedin and Southland are left with the crumbs.

Rain radar - we are covered

But... Otago is completely covered by the Southland and Canterbury rain radars! If anything we're better protected, as being in the overlap between those two radars, we'll still be convered if one of them goes down. A quick look at the met service radar maps shows how well we're covered by them. There's no need for a separate Otago radar.  http://www.metservice.com/maps-radar/rain-radar/all-new-zealand

ODT/directory - Local Businesses

CompanyLocationBusiness Type
Cottage by the Tower Serviced ApartmentInvercargillApartments
Mr Green Home Services - WanakaWanakaHome & Garden Maintenance
Queenstown Resort CollegeQueenstownAcademic Institutions
Bayleys WanakaWanakaReal Estate Agents