The drips under pressure often employ a statistical estimation as a basis of probability and magnitude to label a flood and or a rain event as 1 in 50 year event or similar and in the current disaster in Edgecombe a barely conceivable 1in 500 year event.
Is it time such arrant nonsense is abandoned.
One winter during our 20 years in the Bideford district East of Masterton we endured 3 x 1 in 50 year flood events and 1 x 1 in 100 year flood from the Taureu River. All very academic when a quiet creek rises 40 feet or over thirty meters.
With Earthquakes there is the Richter Scale that has deficiencies over measuring energy but after 10 000 tremors the logarithmic based Richter did give some relevance.
Yesterday in morning bulletins NZME made a claim that the Mason River, a tributary of the Waiau that drains the southern landscapes of Highway 75, the inland route to the South of Kaikoura, was running at 120 cumecs (a cumec is one cubic meter of water every second, of flow). Now that is real understandable data and to moi, however accurate does indicate a massive flow in a stream that with almost zero extraction has barely visible flow in high summer.
To announce to the world that the Bay of Plenty rural town was enduring a 1in 500 event is so trite and meaningless as who in gods name has data going back to c1507.
Whereas had the flow data of the Rangataiki at normal April flow, low flow and known previous flood flows been divulged it could have brought into stark focus the magnitude of what actually hit Edgecombe.