Disentangling facts from fiction related to catastrophic floods should point policy-makers towards a broader perspective than simply focusing on the uplands. The most important policy conclusion is a cautionary one. The role of forests in solving flood problems remains uncertain, although the progress that has been made in understanding upland-lowland interrelationships suggests that forests are much less important than commonly perceived. However, close to the forests in the uplands, they can reduce flooding from frequent, low-intensity, short-duration storms (Hamilton 1986). While it may be convenient to blame upland farmers and poor forest management for problems that affect low-lying areas, it unfortunately does not contribute to solving the problems.
Sound science provides little evidence to support anecdotal reports of forest harvesting or rural land-use practices leading to lower-basin catastrophic floods. When it comes to prevention of major floods, the 'sponge theory' is a historical erratum - a fiction often inappropriately used to justify soil and water conservation measures, forest management controls and logging bans. Unfortunately, the 'sponge theory' has also been used inappropriately to secure funds for various development and governmental projects. Simplistic belief in the flawed approach to flood management distracts the attention of policy-makers from two main points:
1. There are many good reasons - other than for avoiding floods - for protecting soils in Asia’s uplands and for managing upland forests sustainably.
2. Instead of pointing to distant uplands as the source of their problems and dwelling on fictional cause-effect relationships, lowlanders (including policy-makers) should learn to live with rivers and manage the lowlands for what they are - floodplains.
