Cooling my heels atop Baxter peak I happened to overhear parts of an animated conversation among a group of fellow hikers. They were discussing about the rocks and flora in the Grand Canyon. Amidst the chit chat, I heard someone mention the Grand Canyon flood; for which, the response was that it was an intentional, man-made act. That set me thinking.
When flood is one of humanity’s worst nightmares - I am writing this as Irene threatens the eastern seaboard with dangerous floods and devastating tides - and people have always sought to regulate surging waters by weirs and dams, why would man intentionally create a torrent at a rate of 300,000 gallons per second - enough water to fill NY’s Empire State Building in 20 minutes?
The answer is simple enough. Floods play an important role in the ecosystems supported by rivers. Before building the Glen Canyon dam, floods ravaged the canyon every year infusing the river with sediment and building sandbars [Source]. The dam on the Colorado prevented sediment being distributed in an ecologically balanced manner.
The lack of sediment has cleared the normally thick and cloudy red water of the Colorado. This has led to a decline in the population of the humpback chub which had evolved to depend on the rusty red waters to hide from predators. Several other species have disappeared altogether.
One of the solutions was to stage a three-day flood in March 2008 and then to repeat it over a few years to mimic the river’s natural cycles. But, will this help? The 2008 experiment saw an increase in the area and volume of sandbars. However, they had largely eroded within six months [Source]. The torrents during the flooding experiment amounted to 4-5 times the normal quantity of water released by the dam. Yet, this is significantly lower than the great deluges of the past.
Scientists can continue to experiment finding viable strategies for restoring the ecosystem. But a bigger question still haunts us. To what extent can we play God? Over the last few centuries, man has become an expert at controlling and exploiting nature. But we know not of what we do; the long term consequences of each of our seemingly simple acts are difficult to predict. We do not fully understand the damage we are causing, let alone find strategies for repair.
Nature, however is resilient. It will eventually find a way to repair itself, with or without man. Have we already crossed the threshold? Is man no longer in nature’s plan for the future? Have we already signed our own death warrants?
With 2011 set to be become the worst ever year for US weather disasters causing billions worth of damage [Source] and natural disasters also increasingly striking every part of the globe [Source], it is probably the right time to pause and give all of it some thought.
Hoping that the Irene comes to pass without adversely affecting the lives of too many, I conclude this post.