Will 2007 go down as Knoxvilleâ’s driest year ever?
by Rikki Hall
Through October, Knoxville has received 26 inches of rain; 1986 was the driest year on record at 32 inches, so we have the rest of the year to accumulate six inches of rain. Four inches per month is average, but November is off to a below-average start. We may set a new record.
Even if 2007 winds up drier than 1986, that year was but the worst of several consecutive dry years between 1985 and 1988. That four-year drought did not have as much impact on water levels as this yearâ’s lack of rain. All over East Tennessee, creeks and rivers have flirted with record-low flows, and this fall those records were broken. Rivers and creeks dropped lower than they have been in more than a century.
How can we have less water now than during a four-year drought? Soil acts as a sponge, holding rain for some time before it finds its way into a creek. A rain gauge measures what falls from the sky, but creek and river levels depend on the timing of rains as well as the amount. A thunder shower can saturate the ground so rainwater gets in creeks without entering the soil, but most rain filters through soil before reaching a creek or getting slurped up by a thirsty plant. Even though this year has been slightly wetter than 1986, the timing of rains has been worse, so springs and creeks steadily dried up.
Crop yields are down in Tennessee for corn, soybeans, and cotton, but with Texas getting heavy rains and a few tropical storms, nationwide crop productivity is up. The market will not allow Tennessee farmers to soften their losses with higher prices. In Georgia, tomato crops suffered from a whitefly infestation. The aphid-like insects thrive in warm, dry weather. Cattle farmers throughout our region fear a poor hay crop will result in fewer calves next spring.
As bad as the drought has been in East Tennessee, across our southern border things are even worse. Northern Georgia and Alabama and the Carolina highlands are enduring even greater rainfall deficits, triggering water skirmishes. Atlantaâ’s primary water source, Lake Lanier, is in danger of going dry, and the city has sued the U.S. Army Corps of Engineers to force it to release less water into the Chattahoochee River below the dam that makes the lake. Shrimpers, oystermen and others who make a living around the riverâ’s Florida-panhandle mouth need water releases, and the U.S. Fish and Wildlife Service is obliged to protect populations of rare mussels in the river. Several power-generation dams along the river need water releases to spin their turbines. Downstream interests insist that Atlanta did little to quell its water consumption as the situation worsened and has ignored the problem for decades.
On the other side of town, the Coosa River system drains into Mobile Bay, and Alabama says Atlanta has been withdrawing more water from Lake Allatoona than legally permitted. Georgia Gov. Sonny Perdue responded by saying, â“Alabama is trying to use these insane rules of the Fish and Wildlife and the Corps of Engineers to dry Georgia up, and I wonâ’t let it happen.â” Florida Gov. Charlie Crist sent a scathing letter to President Bush asking him to refuse Georgiaâ’s demands, and Alabama Gov. Bob Riley has thrown barbs as well. Bush was able to step in and bring the three governors into productive discussions.
Is all this trouble a result of global climate change? Global warming is no more responsible for a given weather event than a middle linebacker is responsible for the final score of a game, but they both have an impact. The drought is largely a random, natural event, but if we fall three inches below the 1986 record, it would be reasonable to assert that global warming made the difference. That is the basic message scientists are trying to get across: Global warming will make natural events more extreme. Droughts will be drier and longer, floods deeper, storms more violent. Is it insane to worry about those marginal differences, the few extra miles per hour that make a category 3 hurricane a category 4 storm or the few extra inches of rain that distinguish a dry year from the driest ever?
Rikki Hall is managing editor and publisher of Hellbender Press , a non-profit environmental education journal.
All content © 2007 Metropulse .