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“Floods are acts of god; flood damages result from the acts of man.”

  "...as population has increased, men have notonly failed to devise meansfor suppressing or escaping this evil [the flood], but have, with singular shortsightedness, rushed into its chosen paths. "

William McGee,

The Flood Plains of Rivers (IR91)

The fierce power of nature in the form of floods has long held a powerful grip on our thoughts and fears. Ancient religious tradition saw floods as the destructive act of an angry god. The study of psychology has viewed wild nature as a prime source of terror for people, with speculation that the control of nature is a basic human desire. Little wonder then that we have long sought comfort in military metaphors and strategies in order to harness, tame, conquer and battle the threat of wild rivers and uncontrollable flooding.

Such efforts have had their successes. Flood control structures have reduced the intensity and frequency of flooding. But those successes have also diminished our connection with the fact that some floodplains will always be vulnerable to flooding. Indeed, it still seems that every time the skies open up and a huge deluge falls, people shake their heads in amazement (as if flooding was some sort of unexpected event) and then demand we redouble those historic efforts to fully control nature before it lets loose again.

Dr. Jeffrey Mount, a U.C. Davis geology professor and author of California Rivers and Streams. The Conflict between Fluvial Process and Land Use, has called this cycle of flood control construction "serial engineering."" He points out that by preventing small and mid-sized floods, dams and levees can give us a false sense of serenity and security. That sense of protection allows more people and property to be put at risk, which-after a flood revisits an urbanized and supposedly protected floodplain--then prompts a predictable call for more flood control structures.

Thus, in the Central Valley of California, despite spending what is now the equivalent of billions of dollars to create the most comprehensive and highly engineered water works system in the world, damages from flooding continue to rise. For the storm of 1997, harnessing rivers and streams with reservoirs and levees reduced flooding in the Sacramento / San Joaquin valleys to a mere five percent of what it historically was in the region. Despite that reduction through the use of dams and highly engineered channels, the flood still killed nine people, forced more than 100,000 from their homes, and statewide caused an estimated $2 billion in damages." For both California and the nation, a significant portion of flood damages in recent decades can be attributed to an overconfidence in the traditional engineering works of dams and levees. Quite simply, those measures have enticed and allowed urban development in historic floodplain areas--places thought to be completely protected.

The traditional assumption that flooding can be completely eliminated has meant not only an unrealistic reliance on man-made flood protection, but the development of a flood control system which squeezes rivers into artificially narrow channels, adds steeply sloped levees (devoid of riparian vegetation), and eliminates historic floodplains-all in the name of reclamation, flood protection and urban growth. Unfortunately, this highlights the fact that floods have been viewed for far too long as everything except part of the natural life cycle of rivers and floodplains.

THE NATURE OF FLOODS

Flooding is part of the dynamic nature of healthy rivers and ecosystems. The Central Valley, for example, was shaped by its rivers and their periodic floods, all of which helped produce the region's rich soils, agricultural lands, and wildlife habitat. High flows and flood waters are needed to cleanse channels of accumulated debris, build stream banks, import gravels for spawning salmon and steelhead, thin riparian forests and create riparian habitat.

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Nature itself provides its own type of flood reduction systems. The open space of floodplains adjacent to rivers and streams helps store and slowly release floodwaters, thus reducing flood flow peaks and their subsequent impacts during small and frequent flood events. Wetland areas act as giant sponges, soaking up floodwaters in addition to filtering and adding to groundwater supplies. Healthy forests can also slow runoff from mountains and hillsides during small flood events, reducing peak flows, mudslides, and sediment loads in streams.

Restoring the natural meanders of rivers by creating larger floodways can also help accommodate larger flood flows and reduce the vulnerability of some historic floodplains that have been "reclaimed" from periodic flooding for agriculture, development and urbanization.

Experts also have suggested that reducing flood damages requires planning

Continued in Beyond Flood Control Part II

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