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It was March: Illinois was bracing for the worst flooding in 150 years, while Kentucky and adjacent states were cleaning up after record-high water. Much of the upper Midwest faced serious threats. It was just a few short months ago that my own Yuba County was inundated after a levee on the Feather River failed so suddenly; there was no time to notify anyone, much less evacuate the adjacent communities. These disasters offer us many valuable lessons, including how to relate to a government bureaucracy, and insights into wetlands and the weakness of an aging flood control system. Most importantly, they remind us that more human lives are lost to flooding than any disaster. As Landscape Architects, it is essential we learn more about the realities of flood control and understand its extricable relationship to wetland regulation. Before America was settled, the nature of seasonal flooding was very (IS different than it is today. When river flows increased, the water spilled over the banks and spread far out upon the land - but in very shallow depths. Often, the overflow became land-locked, sitting for many months and gradually evaporating and percolating down to recharge the water table. These areas became choked with reeds, providing rich reproductive habitats for a great diversity of wildlife. Since the advent of flood control, river waters are kept in their channel by earthen levees. During sudden spring thaw or heavy rains, the water levels rise quickly because the once spreading waters are now constrained. At flood stage/ the water surface may be fifty feet or more above the surrounding ground plain. The levees cut off the potential to recharge the water table; thus, some regions are finding ground water more and more scarce. An even worse scenario is levee breaks, because the result is high-velocity flash flooding that knocks buildings off their foundations, trapping residents and fleeing motorists. The U.S. Army Corps of Engineers is now at a crossroad as they consider more environmentally sensitive alternatives to the traditional levee barriers that separate the river channel from adjacent lands. Levees are not only unattractive, they degrade riparian habitat and eliminate natural drainage into the river under normal flows, Today, these neighborhoods must pump drainage water up and over the levee to the river. Under heavy rainfall, there is always the risk of street flooding if the pumps cannot keep up or fail entirely. The Corps is studying levee systems in many areas to see if they can be eliminated or reduced in order to return more riparian habitats to our nation's river banks. This would allow for beneficial, shallow flooding, so that those residents who live in the flood plain are at less risk of catastrophic levee failure. This will fuel a demand for the creation of residential flood control measures for low-level flooding around individual homes. LEVEE CONSTRUCTION HAS ELIMINATED MOST OF THESE TRUE RIVERINE FORESTS THAT LINE THE BANKS OF NORTHERN CALIFORNIA'S MANY RIVERS. THE VEGETATION SERVED MANY CALIFORNIA'S MANY RIVERS. THE VEGETATION SERVED MANY PURPOSES, FROM SLOWING FLOOD WATER VELOCITY TO EROSION CONTROL ON RIVERBANKS. All photos provided courtesy of the author.

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June 16, 2019, 10:29 pm PDT

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