Matters that state government, local government and regional planning panels should consider (but more often barely notice in passing) before granting consent for large scale residential developments along the NSW coastal zone.
Take Yamba for instance, bounded by the Clarence River estuary and Pacific Ocean...
Probable Maximum Flood (PMF). The largest flood that could conceivably be expected to occur at a particular location, usually estimated from probable maximum precipitation. The PMF defines the maximum extent of flood prone land, that is, the floodplain.
[NEW SOUTH WALES STATE FLOOD PLAN GLOSSARY , February 2018]
“Evacuation
1. Reliable access for pedestrians or vehicles required during a 100 year flood to a publicly accessible location above the PMF”
[RESIDENTIAL ZONES DEVELOPMENT CONTROL PLAN, effective from 23 Dec 2011 , FLOODPLAIN MANAGEMENT CONTROLS, LOWER CLARENCE RIVER FLOODPLAIN, YAMBA FLOODPLAIN & OTHER FLOODPLAINS]
Evacuation Centre: Yamba Bowling And Recreation Club [SES, CLARENCE VALLEY LOCAL FLOOD PLAN ANNEX J]
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| Click on image to enlarge |
Approach to Yamba Bowling Club for most of Yamba population will be blocked by 1-in-100yr Flood at 2.09-2.2m & Extreme Flood at 3.56-3.68m.
In both flood types Yamba will be isolated from the wider Clarence Valley by floodwaters for a matter of days or weeks.
Since 1990 the Lower Clarence River has flooded on average once every three years.
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