… About a foot and a half of water had fallen across south Florida — not the product of a hurricane or a tropical storm but of a rainstorm, dubbed Invest 90L, a deluge that meteorologists are calling a once-in-200-years event. It was the fourth such massive rainfall to smite southeastern Florida in as many years. … “Rain bombs” such as Invest 90L are products of our hotter world; warmer air has more room between its molecules for moisture. That water is coming for greater Miami and the 6 million people who live here. … A massive network of canals keeps this region from reverting to a swamp, and sea-level rise is making operating them more challenging… The majority of these canals drain to the sea during low tides using gravity. But sea-level rise erodes the system’s capacity to drain water — so much so that (South Florida Water Management District) has already identified several main canals that need to be augmented with pumps.