SAMOA FLOOD MANAGEMENT ACTION PLAN 2007-2012 - Pacific ...

Samoan Government and developers to develop schemes where the flood risk isacceptable to insurers.3.3.5. Improving flood preparedness and responseRecommended actions:Measures to increase the flood preparedness in flood prone areas should include:o Develop flood response planso Raising awareness of flood risk.o Flood warning arrangements and advice to communities, businesses and otherstakeholders on how they should respond.o Preparatory measures by communities and businesses to protect properties andcontents.o Arrangements for public safety including evacuation plans where required.These measures will reduce both the intangible as well as the tangible costs offlooding. One challenge is to maintain an adequate level of flood awareness duringextended periods when moderate to severe flooding does not occur. A continuingawareness programme must be put in place to inform new residents, maintain thelevel of awareness of old residents and to cater to changing circumstances of, forexample, flood behaviour and new developments should be put in place.The flood-prone communities must be made aware and remain aware of their role inthe overall floodplain management strategy for their area, including the evacuation ofthemselves (and possibly personal goods and possessions). Sustaining anappropriate level of flood awareness will involves a continuous effort by variousSamoan Government Departments, community groups and the emergency services.The cost of maintaining a level of awareness should be budgeted for. It should benoted that irrespective of the available warning time, generally there is widespreadvariation in flood awareness, both between households and communities.3.3.6. Land use changeRural land use changeRural land use change (e.g. the afforestation of catchments) is often put forward as amethod of reducing flood flows. The upper Vaisigano catchment, which forms themajority of the drainage area, remains largely covered in trees. Forests interceptprecipitation, and this has sometimes led to the misconception that forests can“absorb” floods, acting like a sponge. In the case of a flood-producing rainstorm overthe Vaisigano catchment, only a limited amount of rainfall (typically up to 5 mm to 10mm) is intercepted which will not in itself have a significant mitigating impact onreducing flood flows. It can thus be concluded that adjusting the rural land use willnot have a significant effect on reducing downstream flood risk 7 .Increasing urbanisation of the catchmentWith respect to urban land use change, the development of houses and businessesin the catchment will increase the impervious area and will often result in a localincrease in flood flows. It is recommended that PUMA puts in place in its consenting7 Forest has very minimum impact on flood controlFlood management Action Plan 2007 38