Fund a program of re-wilding in areas along the Tay, Spey, Don and Dee. Other rivers prone to flooding, which are likely to become more so due to climate change and the onset of winter storms, should also be considered.
The restoration of some of Britain’s missing ecosystems could play a major role in the prevention and mitigation of the kind of floods now blighting parts of Scotland.
If the uplands, where most of our rain falls, are kept bare, rainwater flashes off them. Tree cover greatly increases the rate at which it is absorbed by the soil. This means that instead of rushing off the hills and into the nearest river, it is released more slowly, and the flood peaks are likely to be lower.
Studies of the Pontbren Project in mid-Wales, where shelter belts of trees were planted across sheep pastures, discovered that water infiltrates into the soil under the trees at 67 times the rate at which it infiltrates into the soil under the pasture. The reason appears to be that the tree roots create channels down which the water can flow, allowing the soil to function as a sponge. By contrast, heavy grazing, as a result of the removal of deep vegetation and compaction of the soil by the feet of livestock, ensures that the land is much less permeable.
One research paper arising from these studies estimates that reforesting just 5% of the land reduces flood peaks by around 29%, while full reforestation would reduce them by some 50%.
Designate these areas "Caledonian Forest national parks" with forest walks, stargazing parks and all sorts of nature trails, mountain biking tracks etc.
The trees will help prevent floods, the Caledonia forest could be used as areas to reintroduce wildlife to Scotland and be marketed as tourist attractions.
We reintroduce some mystery into the sometimes barren landscapes of Scotland and we help guard against the future costs of flooding.