By definition, a drought is a deficit of rainfall over an defined period. There are 3 types of defined 'drought' 1. Meteorological 2. Agricultural 3. Hydrological What is being talked about at the moment is a Hydrological Drought For example, if, in the last year, rainfall is 20% below normal and that normal is 30 ins of rain per annum, then there is a shortfall of 6 ins. This means to catch up, we'll need this amount more rain than is normal, just to stand still. However, between April and October, it becomes difficult to replenish ground water supplies as most rain that falls is evaporated back without reaching underground reserves. So, even if the summer months (June-August) get twice their normal rainfall (making up the 6" deficit, a very wet summer), only a small percentage will reach underground storage, so won't make a huge dent in the deficit. Most of the heavy rain that has fallen recently will just 'disappear' back into the atmosphere, or run off to the sea. Therefore, we can have surface flooding, but still have a hydrological drought.