PROTECT THE HAMPSTEAD HEATH PONDS

  PROTECT   THE   HAMPSTEAD    HEATH   PONDS    

THE RISK OF FLOODING IS MINIMAL

The experts believe that all dams should be able to withstand such a severe rain storm. On Hampstead Heath the theoretical storm has been determined to last 4.4 hours for the purpose of the recommendations and mathematical models used to calculate the estimated damage and water flows.

At a  presentation by the City of London on 1 August 2011, David Lewis of the Protect Our Ponds Campaign asked: "What does a 1 in 10,000 year probability mean?"

He  added "The storm is assumed to last 4.4 hours, not a whole year. There are  8,760 4.4 hour time periods in a year. So isn't the real probabilty of such a  storm happening 1 in 87.6 million?" The experts present did not deny this suggestion nor attempt to explain any fallacy in the argument (if there is one).

Even if such a storm did happen, there is no guarantee that it would have catastrophic consequences.

Dam engineers have told the City of London that the dams on Hampstead Heath must be able to resist a catastrophic rain storm which is only likely to occur once in 10,000 years. Put another way, it means that there is a 99.99% chance of the rain storm never happening. The Protect Our Ponds campaign reckons this is so remote that  in reality it will never happen. 

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