Q: Do meter readers in DeKalb County actually check my water meter before I receive a bill? With the recent water restrictions I have severely cut my water use yet see no decrease in my bill.

SUZANNAH HEIMEL, Decatur

A:Water meters are read every two months in DeKalb County, said Sandra Leavell, county spokeswoman. Your meter was probably read prior to your conservation efforts, which should be reflected in your next bill.

Q: How many dams are on the Chattahoochee River between the Buford Dam and Apalachicola, Fla., and who controls the water flow of those dams?

ROY FOREMAN, Dacula

A: There are 13 dams along the main stem of the Chattahoochee River. These dams help maintain river water levels and provide hydroelectric power.

Dams operated by the Army Corps of Engineers include Buford Dam, West Point Dam, W.F. George Dam, and George W. Andrews Dam.

Georgia Power owns and operates Morgan Falls Dam, Langdale Dam, Riverview Dam, Bartletts Ferry Dam, Goat Rock Dam, Oliver Dam and North Highlands Dam. The other two dams City Mills Dam and Eagle and Phenix Dam are inactive.

The Jim Woodruff Dam, also operated by the Corps, is located on the Apalachicola River about 1000 feet below the confluence of the Chattahoochee and Flint Rivers.

Q: For homes connected to sewer systems, why is there a need to restrict indoor use since most of the water is returned to the river after it is treated?

Bruce Bennett, Atlanta

A: All water utilities in the 61 North Georgia counties in extreme drought are required by the state to reduce water use by 10 percent. To meet that requirement, utilities must reduce customer demand for water, indoors and outside, said Jennifer Carlile, spokeswoman for Atlanta's Department of Watershed Management. Utilities are being monitored on water being withdrawn, treated and put back into the water distribution system.

Q: When was Buford Dam completed and how long did it take for Lake Lanier to fill?

LOURENE COLLINS, Stone Mountain

A: The intake gates closed on February 1, 1956, beginning the process of filling the reservoir that was to become Lake Sidney Lanier. It took over three years for the lake to record its normal elevation of 1070 feet above sea level for the first time on May 25, 1959.

Q: Why isn't rain being induced by planes spraying the clouds with chemicals?

HERMAN SCOTT, Riverdale

A: Cloud seeding, also known as weather modification, involves spraying clouds with silver iodide and dry ice to make more rain. Cloud seeding doesn't produce rain, it just increases the amount of precipitation already in the clouds. In 2003, scientists at the National Academy of Sciences concluded there is no conclusive scientific evidence that it works. However, the academy recommended that research continue on weather modification.

Q: I was taught that allowing outdoor spigots to trickle during an overnight freeze would help to prevent a burst pipe. Do the current water use restrictions permit dripping spigots?

SCOTT B. LOGAN, Atlanta

A: Yes, you are permitted to allow your spigot to drip in the event of a freeze, said Jennifer Carlile, spokeswoman for the City of Atlanta's Department of Watershed Management. Carlile suggests placing a bucket under the spigot, if there is room, to catch the dripping water to use elsewhere.

Q: A pie chart showed water usage by type of consumer. A segment of the chart indicated that 18 percent of water usage was "unbilled." What is an "unbilled" use?

PAMELA J. PITTMAN, Marietta

A: Unbilled water includes fire hydrants, water system maintenance, some municipal uses and leaks or breaks in the system. Fifty-five percent of all water consumed in the Atlanta area is for residential use.

Q: What is the status of the apple crop in north Georgia because of the drought?

JEAN BATEMAN, Conyers

A. This year's apple crop is much smaller than usual, says Clayton McDuffie of the Georgia field office of the National Agricultural Statistics Service. Both the Easter freeze and the drought are responsible. As of mid-October, the crop condition for 75 percent of Georgia apples was listed as "very poor," while 20 percent of the crop was "poor," 5 percent was "fair," and none was rated "good," or "excellent."

Q: When was the last time that we had a drought in Georgia?

RICK BREWER, Smyrna

A: In recent history, Georgia has had droughts in 1981, 1986 and 1988, and then 1998 to 2002. The current drought began in spring 2006.

Q. Due to the severe drought, Georgia residents are being asked to limit household water usage to a certain number of gallons per day or month. The bill we receive from our water provider, however, does not state our usage in gallons, but in "CCF." How do we convert CCF to gallons?

ANNE FERGUSSON, Gainesville

A. CCF means one hundred cubic feet of water and 1 CCF = 748 Gallons. So if your water bill for 2 months indicates a consumption of 22 CCF, you have used 16,456 gallons, or about 274.3 gallons a day over 60 days.

Q: Years ago we were advised to put a brick in our tank to reduce the flow of water. Is the brick in the toilet tank still a good idea?

L.H. JORDAN, Sautee, Fla.

A: Don't use a brick in your tank. Bricks disintegrate over time and could damage the plumbing. Instead, the Georgia Environmental Protection Division recommends placing a milk jug cut in half and filled with stones in the tank if your toilet is pre-1993. Older toilets may use between 3.5 to 7 gallons per flush. You can check the date of manufacture by looking at the underside of the tank lid where it might be stamped into the porcelain. Consider replacing your older toilet with a new, efficient model using 1.6 gallons per flush. Don't place anything in a newer low flow toilet tank which needs the water to function properly.

Q: Is it true that there are no natural lakes in Georgia, that all the lakes are man-made?

JAN BINKLEY, Barnesville

A: It is true. Kevin Chambers, spokesman for the Georgia Environmental Protection Division, says any body of water in the state large enough to be called a lake is man made. Lacking glacial retreat and land slope, local geology provided conditions for large and small rivers and streams but not for lakes.

Q: What is the source of the water in Candler Lake on the Emory University campus?

JOHN WILLIAMS, Decatur

A: Candler Lake, the man-made lake on the Lullwater Estate, is fed by two creeks which originate on Emory University property. An unnamed creek which is fed by natural springs flows into a biological research pond, and then into Candler Lake. The second stream, Ernest Richardson Creek, is fed by a spring and by water run-off from the campus. Tim Bryson, former chair of Emory's Committee on the Environment, says that the university is working to restore Richardson Creek and to minimize its continued environmental degradation.

— Staff researchers Joni Zeccola, Alice Wertheim and Sharon Gaus contributed to this column.