Per Bak, the Danish Physicist who described the concept of complex and organized instability by use of sand could have also used the White River and river management. Bak described how if you dropped sand, one grain at a time from the same location that a cone would form as each grain was added to the pile. At indeterminable intervals, the cone would reach a degree of slope that was not sustainable and a small avalanche would occur. It could come from the adding of one grain, or it could come from adding a thousand grains, because of the many other factors that came into play. As the grains of sand piled up, the cone would form organized instability, where it may look stable and predictable but in fact be purely unpredictable and unstable. Glen Held, a scientist working for IBM in New York’s Watson Research Center duplicated this concept and discovered another constant in this theory, and that is even duplicating the manufacture of the sandpiles exactly, because of the complex factors that come into play, no two piles would act the same.
Applying this concept to the issues on the White River in Washington State we have a river that we know transports an extremely high amount of gravel (estimated by USGS to be over 750,000 tons of sand and gravel each year) we can understand why in spite of millions of dollars being spent on modeling and studies to address flooding on the lower White River, the flood threat continues to increase. With the myriad of forces that come into play on any river system, I really question the ability to really accurately model the impact of mitigation efforts with accuracy. A flood on the White River is so complex and has so many factors that you could release the exact amount of water a thousand times and see different results every time.
Among this multitude of external factors that can impact flooding is ground water saturation, tributary inflow, how much debris is currently moving down the river and where it settles. Applying Bak’s hypothesis to the White River explains why the water released in January 2009 that was expected to create only nuisance flooding actually flooded 101 homes and 15 businesses, many of whom were outside of the 500 year flood plain. Much of the same way of thinking that was used looking at the capacity of the river in 2009 is being used to create the modeling of mitigation efforts today.
In a previous blog post I discussed how we need to reexamine the flood plain management principles that have failed us over the past 20 years. Adding the fact that the river systems are not just simple models that can be predicted, it further shows why our river management policies should be closely reviewed and modified. What we are doing is not working and applying Bak’s concepts to the river system add even more uncertainty, at least in my mind, that it ever will. We need to realistically look at removal of at least part of that 750,000 tons of debris that are clogging our rivers and really be good stewards of our environment. It goes back to the question, 30 years ago we did do regular maintenance of our rivers and we had plentiful fish runs. Through a myriad of factors we saw those runs reduced to dangerous levels and stopped the regular maintenance. Since that time we have seen limited evidence that our practices are helping salmon recovery and plenty of evidence that our practices are putting lives, property and the overall environmental heath in jeopardy. It is time to try something differently.
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