|A perspective on the so-called "100-year flood"|
| What is a 100-year flood? A 100-year flood is the flood that will occur on average once
every 100 years. It has a probability of 1% of occurring in any given year. That gives it a lesser probability than
death and taxes! |
"Riverbend" and several of its neighbouring properties are deemed to be in a "100-year" flood zone. A "100-year" flooding could occur if extremely long and heavy rains in the surrounding mountains coincided with an extremely high tide at the mouth of the river. The rainwater run-off coming down the Clyde River would be prevented from emptying into the Bay and instead inundate the banks of the river. As a high tide is followed within six hours by a low time, such extreme flooding would be very short-lived. No flooding, not even a mild inundation, has occurred in the time of the current ownership which is almost 20 years.
Many properties in Australia are located within "100-year" floodzones. Many are located in areas which are regularly "flood prone"; many others even in flood plains. In past times, buildings and other improvements were erected on those properties without any interference from Councils. In more recent times and after more statistical data on flooding had been accumulated, Councils, having had to protect themselves against possible litigation, have been more reluctant to issue building permits in areas which could be affected by flooding. As one Council employee put it, "We spend half of our time just covering our own backs."
The approach taken by Council has been that "what already exists may be repaired and replaced" but that new buildings would have to satisfy more stringent tests. That is not to say that no approval would ever be given as there are several examples of new houses having been built in the "100-year" flood zone of Nelligen; however, it may take a lot longer and be more difficult to obtain such approval (and it would help knowing one's way around the myriad rules and regulations and the right person to talk to).
It is likely that in the case of "Riverbend" which already has its complement of main residence, guest cottage, garage, workshop and shed, Council would see lesser urgency in granting permission to build (say) a second residence than, for example, in the case of the vacant block of land by the Nelligen Bridge in Thule Road. That block, a tiny quarter-acre, is as low (or as high, if you will) as the lowest part of "Riverbend" and yet, a house was built on it in 2003. Likewise, the Nelligen Tourist Park which is possibly even lower than "Riverbend" and is also rated as Rural 1(a), had several accommodation units built on it. Perhaps they were classed as 'demountables' or mobile homes but for all intents and purposes they are as permanent as any house.
The present owners of "Riverbend" have never tested the availability, or otherwise, of a building approval for a second residence. Council does not issue "in principle" decisions in such a matter so that any application would need to be supported by plans for a specific building of which the present owners have no need. It is known that Council has on its files an approval which was given in 1986 for a second residence to be built on "Riverbend" which, however, was never taken up and has since expired. Any prospective buyer who bought "Riverbend" with a view to building a second residence on it now or developing the seven separate building blocks individually, would have to be prepared for a long and hard "fight" with Council; however, they should also take heart from the fact that an owner has a lawful, and indeed constitutional, entitlement to build on any residential land in Australia. The only thing the Council can do is impose conditions based on their determination that some of the land is below the 100-year flood level. If engineers could prove that development problems with the land could be overcome by building on concrete piers and sewage problems could be solved with adequate treatment devices, then Council would find it difficult to completely deny a development application for the construction of a second house or indeed a house on each of the seven block.
At present the greater part of "Riverbend" has been allowed to revert to its original state in which it harbours a multitude of birds, some possums and wombats, and the occasional kangaroo. It is a haven of unsurpassed peace and privacy.