We goofed, big time. When Europeans settled in North America they believed it was "what you see is what you get." As they planned for growth and expansion they didn't understand that what they took as normal was anything but. The science wasn't available to warn them that, throughout most of North America, the 20th century was unnaturally wet or that some areas we intensely developed were subject to naturally-occurring megadrought.
That's not to say there weren't clues. There is a reason the Great Plains were mainly grassland with the odd, stunted tree growth. Let's call that reason historical sustained drought. Yet, during a wet century, we were able to populate the land complete with towns and cities based on unduly wet conditions.
Oopsie! Now we know we had it wrong. Now we can use tree-ring based hydroclimate reconstructions to peer into the past. And they're painting a much different picture than the assumptions we used in planning our expansion and development. A recent study looked at Georgia and that state's history of prolonged and repeated droughts.
The reconstruction shows that the recent droughts are not unprecedented over the last 346 years. Indeed, droughts of
extended duration occurred more frequently between 1696 and 1820. Our results indicate that the era in which local and state water supply decisions were developed and the period of instrumental data upon which it is based are amongst the wettest since at least 1665.
Given continued growth and subsequent industrial, agricultural and metropolitan demand throughout the southeast, insights from paleohydroclimate records suggest that the threat of water-related conflict in the region has potential to grow more intense in the decades to come.
...Given recent water shortages and emerging challenges,
Georgia and adjacent states have revised water management
plans to include greater focus on conservation and efficiency
(MNGWPD 2009). Unfortunately, many water allocation
plans are based on limited 20th century records and capture a
narrow range of potential moisture variability (e.g., Stockton
and Jacoby 1976).
Yet with the return of protracted and severe droughts and the ongoing depletion of regional groundwater reserves, Georgia officials show little interest in responding to their problems. Instead they're planning for huge growth, up to 60%, in water demand by 2035 even assuming a 20% decrease in per capital water use. This is a candle burning fiercely from both ends.
Fortunately for the US south and southeast, they're blessed with truly inspired leadership from Georgia's governor Sonny Perdue to Rick Perry of Texas. When drought strikes them they know how to respond - they declare official days of prayer for rain.