For many homeowners in Sonoma and Napa counties, nothing could have been more welcome than the splashing of rain that fell on Northern California last Thursday – the first significant precipitation in about five months. The rain helped put an end to the fires burning in the area, which first ignited on October 8, and have wreaked hellish destruction on Santa Rosa and other communities. However, the recent rain – and the precipitation to come in the months ahead – will bring considerable environmental impacts of their own, especially to the waterways, and even water treatment plants, downstream of destroyed forests and incinerated neighborhoods.

It is by now a familiar story: The storm hits, the cities flood, dramatic rescues ensue to save people from the rising waters, followed by the arduous and expensive cleanup. But chances are you’ve thought less about the deadly and economically destructive consequences of a slower-moving culprit: drought. Repeated droughts around the world are destroying enough farm produce to feed 81 million people for a year and are four times more costly for economies than floods, the World Bank found in a new study.