Flooding will have continuing effects around the globe

Floods are so common that we seldom pay much attention to them. But lately floods have become more severe and weather forecasters are saying that they are only going to get much worse.

Of the several climate-related disasters, floods are probably the most universal; big or small, they occur almost everywhere. In the summer of 2022, we have been seeing footage of record breaking rains and floods all over the world: Australia, India, China, South America, and Europe. Over 1,000 people are reported to have been killed by flooding from the recent storm in Pakistan. In the United States, huge storms this summer that have resulted in massive flooding have occurred in California Texas, Missouri, West Virginia, Kentucky and several  other states.

Anywhere the land is not protected with sturdy planting (i.e, areas recently mined or logged and with especially dry soil) fierce rains are likely to create unstable mud. The mud clogs normal drainage systems further impeding drainage. The bigger the rainstorm, the more likely there will be a significant accompanying landslide.

The recent floods that have bedeviled West Virginia and Eastern Kentucky are the result of inadequate preparation for dealing with massive flooding. But the mountainous natural terrain and the derelict landscape from unreclaimed  “mountaintop removal” strip mining almost guarantees major erosion and flooding.

Little exists to channel the flood waters away other than small existing streams and roadways. Most of the rural residents live in low lying areas known as “hollows” which are quickly flooded out, most recently leaving over 40 people dead.

Climate researchers at UCLA have recently predicted a megastorm in the Pacific Ocean that will envelop California sometime in the next 50 years. (Readers may have encountered the term “atmospheric rivers” to describe  enormous concentrations of water vapor in the sky that are instrumental in the progression of rainstorms, particularly on the U.S. West Coast. A further description requires a much longer article.) They anticipate a month-long rainstorm over the entire state. Apparently such storms have occurred in the past every few hundred years but none has happened since the 1860s, when the state’s population was tiny. Now California has nearly 40 million people and grows over a third of the nation’s food in its flat Central Valley. This megastorm would be an unprecedented disaster.

The Northeast has perhaps the most benign climate in the United States,  northwest Connecticut’s particularly so.  While we have weather disasters like other states, they’re usually milder (currently we’re experiencing a drought but nowhere near as severe as that devastating the far West).

Many Connecticut old-timers still talk about the flood that nearly destroyed the town of Winsted in 1955. Apparently a pair of strong back-to-back storms veered off their usual course and headed inland, nearly destroying the heart of the Winsted and other locations in Connecticut, and killing at least 87 people. After this flood, the U.S. Army Corps of Engineers came in and created a dam above Winsted on the Mad River that can be seen to the right as a large berm when you are driving into Winsted on Route 44 from Canaan.

While flooding seems inevitable, there are still ways we can moderate its impact. In the U.S., a typical death toll after a serious flood has dropped over the past few decades, largely because of more timely and accurate forecasting and communication. This will continue to improve and combined with better emergency services including rescue and shelter will reduce accidents and death.

Engineering solutions such as providing more levees and flood walls, dredging creeks to greater depths, and increasing drainage piping where useful will help us better cope with increased flooding. Many new and existing structures can be raised “on stilts” as is happening more and more at seaside resorts (it may not be beautiful but can sometimes prevent beach houses from being washed away in a storm).

Better public drainage systems with well maintained natural swales or drains and piping to impoundment areas (ponds, lakes, or their natural or man-made reservoirs) make a big difference. Paved areas, especially large ones such as parking lots tend to flood even after a moderate rainstorm and since they are usually flat do not drain well unless special attention is given to collecting and dispersing the water.

Flooded basements are a common household complaint even without a major storm. Proper grading around a building is critical to avoid having flood water entering the building. A conservative rule would be to slope the ground at least 10% away the face of a building for some distance. Where this may not be possible, drain and channel the water through swale or pipe to a suitable downhill location.

Architect and landscape designer Mac Gordon lives in Lakeville.