Dam adding to plight of spider lily

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There are lots of reasons why the Savannah River's Rocky Shoals Spider Lily is endangered, and a newly-published study by two local professors has found at least one more: the excessive changes in river flow caused by hydropower generation at Thurmond Dam.

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Augusta State University professor Donna Wear looks for a spider lily she can study for research. The rare flower is endangered.   File/Staff
File/Staff
Augusta State University professor Donna Wear looks for a spider lily she can study for research. The rare flower is endangered.
Video: Augusta Outdoors
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In a peer-reviewed article in the current issue of the Natural Areas Journal , biologists Judy Gordon and Donna Wear share their multi-year comparison of two separate populations of the aquatic flower -- one in the upper reaches of Stevens Creek and the other in the Savannah River below Interstate 20.

Although the Stevens Creek population is thriving, the one in the river is slowly disappearing.

Historically, the river's flow was subject to natural surges and droughts, but records indicate those highs and lows are much farther apart and can be more prolonged than before Thurmond Lake was impounded more than 50 years ago.

The consequences include dry spells that cause seedlings to wither and die; and torrential flows that can strip pollen from the plants and sweep bulbs downstream into water too deep to allow germination.

Hydropower generation at Thurmond Dam requires erratic flows to provide electricity during peak demands.

Although the project reports releases as "averages" in cubic feet per second, flows can actually be very high for a few hours and then be reduced to almost nothing the rest of the day.

For example, an average flow of 5,000 cubic feet per second might include several sessions where as much as 35,000 cubic feet per second was flowing downstream.

Such surges can alter water levels by four to five feet above the Stevens Creek Dam, and by lesser amounts downstream.

Gordon and Wear also observed a second factor. Deer seem to be eating a lot more of them in the river, and fewer of the plants in Stevens Creek.

The likely difference, they wrote, is that plenty of hunting goes on near the Stevens Creek population near rural Plum Branch, S.C., while minimal hunting occurs along the Augusta Canal and in nearby North Augusta, leaving more deer to compete for less forage.

DRAGBOAT HONORS: The 25th annual Augusta Southern Nationals dragboat races held last July earned the Race of the Year trophy during the Lucas Oil Dragboat Racing Series' awards ceremony held in January in San Antonio, Texas.

"We feel like that is quite an accomplishment and we are very grateful," said Jeff Banks, former race chairman and current hospitality chair for the event. "It is quite an accomplishment, not only for us, but for Augusta."

The series includes about 30 races nationwide, of which the Augusta event is among the oldest. Banks and his wife, Debbie, traveled to Texas to accept the award.

DNR PROMOTION: A veteran law enforcement officer from the Georgia Wildlife Resources Division's Thomson office was chosen recently as the new regional supervisor for the division's Gainesville, Ga., office.

Capt. Mark Padgett's 25-year career includes stints in Brunswick, Gainesville and Lake Hartwell. Since 2004, he had served as the Region III (east Georgia) administrative sergrant.

CRACKERNECK: Aiken County's Crackerneck Wildlife Management Area will open to the public March 5, 12 and 19 to allow scouting, fishing and other activities.

The area includes 10,470 acres owned by the U.S. Department of Energy along the Savannah River south of Jackson, S.C. Access is off Brown Road near U.S. Highway 125. To request a map, call (803) 725-3663 or send an e-mailed request to: CaudellM@dnr.sc.gov.

Reach Rob Pavey at (706) 868-1222, ext. 119, or rob.pavey@augustachronicle.com.

Rocky shoals spider lily

- Found only in a handful of places in Georgia, South Carolina and Alabama, the plant has almost vanished from eastern rivers because of habitat loss.

- The rare, aquatic member of the amaryllis family requires clear, cold, free-flowing water and an uneven, rocky bottom.

- An endangered species in Georgia, the plant is a candidate for listing on the federal endangered species list.

- Blooming from May to July, the plant's greatest threats are loss of habitat and deer grazing.

- First identified in the 1700s by famed naturalist William Bartram, the lily is included in early writings about the Savannah River.

- The spider lily's seeds sink to the bottom of fast-moving rivers to root in rocky crevices. The plant's common relatives have floating seeds.

Source: The Nature Conservancy, Augusta State University


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