the cistern

Last year we told you about the United States Global Change Research Program's latest findings for the Southeast:

Increasing temperatures and longer periods between rainfall events [code for droughts] coupled with increased demand for water will result in decreased water availability. The 2007 water shortage in the Atlanta area created serious conflicts between Georgia, Alabama, Florida, the U.S. Army Corps of Engineers, and the U.S. Fish and Wildlife Service. Such competition for limited water supplies is expected to continue.

That report seemed almost laughable to some, coming during the monsoon conditions of 2009. Now this federally-mandated research is starting to look pretty reliable. State climatologist David Stooksbury's latest report says drought conditions have returned to north central, west central and southwest Georgia. The rest of the state is classified as abnormally dry. “Temperatures across the state have been above normal this summer, increasing water loss from the soils by evaporation and plant water use,” he said. With temperatures remaining in the 90s and low 100s with little or no rain, Stooksbury said soils statewide will continue to dry. This will lead to increased plant stress, and soil moisture and stream flows will continue to decline.

Exacerbating the conditions for drought next year is the predicted return of the La Niña pattern this winter. This ocean-atmosphere system is associated with dry, warm winters across much of the Southeast, Stooksbury said.

Meanwhile, a federal ruling drastically reducing Georgia's rights to water from Lake Lanier looms less than two years away. Still, the presiding Judge had to issue reprimands to all the stakeholders mentioned above for being too placid on negotiating a solution.

Sounds like conditions are right for a perfect storm. A perfect dust storm, that is...

One recent sweltering August we made the mistake of tent camping on St. James Island in Charleston, SC. It was one of the hottest summer experiences of my life. Evening temperatures stayed in the 90s. It was very difficult to sleep at night for a man grown accustomed to the simulated autumn environment of air-conditioned bedrooms. Relief came at about 2 - 3 a.m. every morning as thunderstorms would form over the ocean and blow inland. As the downpour passed over our campsite, I joyfully stood outside the tent in just my swimsuit. A few hours of blessed sleep came as a result of the rain shower cool-off.

Did you know that rainwater can be used to cool homes?

The simplest most elegant approach I've seen is employed on a home in Turkey where the roof was constructed as a shallow pool. Collected rainwater cascades from an upper level to a lower in a continuous loop. As you can see from the photo, this natural passive cooling system harmonizes beautifully with the landscape.

A regenerative passive cooling project funded by the German Environmental Foundation takes a slightly more complex approach. Harvested rainwater is pumped from the cistern to the roof at night. As the water runs back down the roof it is cooled by heat dissipation due to heat interchange with the atmosphere, convection and some evaporation. By the time the water cycles back through the downspouts and filter it has cooled to just below dewpoint. During the day, the heat generated by the building's cooling system is fed back into and stored in the cistern by a heat exchanger. That evening, the cycle repeats, cooling the heated water for the next day. It's essentially a geothermal system in miniature.

Sanyo is developing a system that purifies the rainwater with ozone and sprinkles it on the roof where heat is taken from the roof as the rainwater evaporates. This reduces the air conditioning load. Evaporation also helps when outdoor condenser units are sprayed with rainwater when the temperature is high, improving the cooling capacity. This stategy results in the conservation of energy.

These solutions may make you want to reconsider how much rainwater you collect. In hot areas that receive a lot of rainfall like Atlanta, it may be wise to collect and store as much rainwater as possible. That way you can add supplemental cooling to the list of uses for rainwater.

Paul Elkins responded to a Shelter-in-a-box design challenge with the "Cadillac of homeless shelters." The challenge was to design a mobile shelter to meet the demands of an ever expanding homeless population. The cart would serve as a recyclables collection vehicle by day and transform into an enclosed shelter at night for sleeping.

What caught our eye was that he designed it with rainwater harvesting.

The roof acts as a raincatcher. A first flush system diverts the initial debris when it first starts raining. Then a turn of a valve starts the collection of free water. An overflow feature allows excess water to drain to the ground. Two screens filter the water, but it is not intended for drinking without further purification measures.

More to peep here...

A key issue to be faced by Georgia's next Governor will be the conservation and management of our water resources.

The University of West Georgia will hold a forum on Friday, April 23, to discuss the state’s water issues. The climax of the day will be a debate among the candidates for Georgia governor from both major parties. Candidates committed to date include Republicans Jeff Chapman, Nathan Deal, Ray McBerry, John Oxendine and Austin Scott and Democrats Carl Camon, DuBose Porter and David Poythress. The candidates’ forum will be moderated by Fox 5 Atlanta TV news anchor Deidra Dukes and will begin at 7 p.m. in the UWG Coliseum.

The all-day event, “Legal and Operational Challenges to Water Conservation,” will feature discussions by water experts from across the region and nation and is open to the public.

For more information, visit www.westga.edu/water.

Tribes have been fighting over water since the dawn of man. To witness the Georgia/Florida/Alabama water wars over the last two decades, it seemed little has changed.

H.B. 1094 is noteworthy, not only because it ushers in a "culture of water conservation", but because it displayed a rare instance of cooperation among various groups that do not typically agree.

Author of the House Bill, State Rep. Lynn Smith, R-Newnan, calls it the good neighbor bill for two reasons:

1. It shows Alabama and Florida that we are taking measures in conservation seriously in Georgia

2. People from all over the state and both sides of the aisle have come to the table and negotiated and made compromises

How refreshing to see this cooperation in a house normally divided!