Flood Forecasting

It was obvious that the requirement for a better flood forecasting system was:

1. a more detailed, timely and accurate forecast of rainfall;


2. a forecast of the amount of rainfall which would be stored in vegetation and on or under the ground so that a forecast could be made of the amount of water entering tributaries and rivers (run-off); and


3. a forecast of river levels at a series of locations along the river, particularly in areas where stock were grazed and where measures could be taken to protect human life and property.

To attempt to introduce such a system on a broad scale was futile. There was pressure on Len Dwyer to develop a system for the Hunter River but Len said "everyone talks to me about the Hunter. I want something simpler to start with". The Macleay County Council had sought the help of the Bureau after the 1955 floods and this no doubt persuaded Len Dwyer to select that catchment on the north coast of NSW for the development of the Hydrometeorological Section's first flood forecasting system. Brian Watson, a hydrological engineer who had worked on the Macleay catchment for the County Council at Kempsey was recruited to serve in the NSW Divisional Office.

Len Dwyer later arranged for Allan Rainbird and Neil Body to attend the first session of the WMO Commission for Hydrological Meteorology (CHM) in Washington DC in April 1961. An earlier paragraph has described the discussion Len Dwyer had with the chairman of the Overseas Visits Committee when told that only one of the two could make the visit.

The creation of CHM within WMO caused a similar bunfight to that which occurred in Australia when the Bureau first sought to enter part of the hydrological field. Some overseas directors of meteorology were afraid that the much larger hydrological services in their countries would absorb their meteorological services and there was long and acrimonious debate extending well beyond the Dwyer years. There is no doubt that Len Dwyer and Reichelderfer (Chief of the US Weather Bureau) would have been instrumental in overcoming this opposition when the subject was debated in the WMO Congress and its Executive Committee.

Bureau of Meteorology