Of course when the waters are rising, threatening homes and lives everyone wants a solution right now. The trouble is that there are no short term solutions to this much water. A shortage of long-term thinking got us into this mess in the first place. We can only hope that more short-term ‘problem solving’ does go on to make things worse.
Yes, in the short term if you dredge rivers you can move more water through them at a faster rate. However, what that does is causes more erosion to banks. There are two consequences here – eroded banks are more likely to give way in face of higher water pressure, which means an increased risk of flooding. All that eroded material goes into the river, silting it up, so you have to keep dredging to keep this under control. By destroying the natural ecology of the river you create an ongoing problem that you then have to keep throwing human solutions at, or you get more floods.
All of our problems here are really of our own making. We’ve built on flood plains. We’ve drained wetlands. We’ve laid down non-permeable surfaces (tarmac, concrete, buildings) and this means water is moving faster. The faster water flows out of our towns, the more likely it is to cause flooding. Once upon a time we had flood meadows, and marshes to soak up the excess, and water could seep in where it landed to a far greater degree. Our collective approach to development has caused this problem.
If we insist on ignoring these basic facts about how water moves through the environment, all we are going to do is invent ever more expensive flood protection schemes that do not deliver protection.
If we build on flood plains, we will get floods in those areas. If we destroy wetlands, we lose capacity for managing water. Yes, right now flooding is a big issue for farmers, but we need a totally different attitude to the value of those flooded fields.
Heavy rain isn’t going to magically go away. We need long term solutions to the underlying problems, not political quick-fixes that just move the problem down to the next town downstream, or the next generation, or some other unfortunates who inherit double the damage and an exorbitant bill. We need to start recognising there is a direct relationship between what people do, and what happens in our environment.