FFDP - Flash flood diversion plan
In response to Queensland flash floods 2011. Concept document. Key elements of a flash flood diversion plan (FFDP). A very rudimentary drawing but addresses key elements of the plan. Damage of flash flooding is related directly to the course of and huge speed of a temporary water flow. Therefore a FFDP does not seek to stop flooding but to ameliorate risk by changing the watercourse. Here we look at a small hamlet on the banks of a creek subject to flash flooding. We reduce the direct flow of a flash flood to the highest levels of the creek and we divert the course of the flash flood to the next valley which does not have domestic dwellings. The hamlet may get flooded but it will not get taken out by a flash flow. If this plan is impossible the hamlet needs relocating. If the hamlet is a town, it is not impossible but a must, and probably requires a lot more complex FFDP, but the elements are the same. In our simple diagram, the key to success is C1 and C2. C1 is based on normal creek high level flows. C2 is based on 1974, 2001 flash flood flows.