An ebbing spring is a cold water spring that stops and starts, thereby flowing intermittently.
They are also called periodic springs, siphon springs, tide springs, and rhythmic springs, according to Wikipedia.
Typically their stopping and starting takes place fairly regularly on a time-scale of minutes or hours.
Ebbing springs are uncommon. A 1991 article in the “Journal of Hydrologic Science” conservatively estimated that there were no more than a hundred ebbing springs scattered around the world, with only one of those in the US.
However, a later 2014 report by Virginia cave explorer Philip Lucas says that Virginia alone may have as many as a dozen ebbing springs.
The ebbing spring in Smyth County is on the north bank of the Middle Fork of the Holston River, about four miles west (downstream) of Chilhowie.
The spring is easily reached by canoe, but lies at the edge of a very large milk and dairy farm, and is not publicly accessible over land without permission.
According to the Virginia Department of Conservation and Recreation, much of the I-81 corridor in western Virginia is underlain by limestone (and its relative, dolostone) bedrock.
The karst landscape that results is caused by water dissolving the limestone to yield sinkholes, sinking streams, caves, underground channels and large flow springs.
Such landscapes are characterized by underground drainage networks that commonly bypass surface drainage divides. The first such recognized landscape was on the Karst Plateau in Slovenia.
Karst landscape is favorable for the formation of ebbing springs because of its underground cavities and channels.
Thomas Jefferson wrote about ebbing springs in his well-known book “Notes on the State of Virginia,” published in 1785. He calls them syphon fountains.
The accompanying modified Jefferson diagram shows schematically how an ebbing spring works. This diagram derives from page 37 of the 1955 reprint of Jefferson’s “Notes.”
Jefferson designated the reservoir “d.” This reservoir cavity is slowly filled with water percolating into it from the surrounding rock. When the reservoir rises to the level of the dotted line, the siphon designated “a,” “c,” “b,” begins to operate. With the siphon operating, water flows to the spring outlet at “e” and continues until the reservoir empties. Then, flow stops and the process begins again.
This columnist visited the Smyth County ebbing spring in April 2008. His old friend and retired dairy farmer, the late Lawrence Richardson, made arrangements with dairy farm owner Dave Johnson to go there.
In Lawrence’s pickup truck, we followed Dave (riding his little four wheel off-road, trail vehicle—a dirt bike) down to the lower end of the farm where Dave directed us across a newly planted rye field to the Ebbing Spring.
Lawrence parked above the spring and I first visited the adjacent site of the Ebbing Spring Presbyterian Church.
At the church site the marker reads: “Site of the Ebbing Spring Presbyterian Church and burying ground built by the pioneer settlers of the community and congregated by Charles Cummings in 1771. Erected by Glade Spring Presbyterian church 1978.”
Rev. Charles Cummins is famous as being one of the men associated with signing the Fincastle Resolutions of 1775.
The Ebbing Spring church is also notoriously famous for an incident in 1780 involving General William Campbell—the hero of King’s Mountain. As recounted by historian Lewis Preston Summers, the General and his wife Madam Russell (a sister of Patrick Henry) attended service at the church one Sunday.
As they were leaving to go home, the infamous Tory and alleged horse thief Francis Hopkins rode up across the river.
Campbell chased Hopkins and caught him in the waters of the Middle Fork of the Holston. A drumhead court followed, and soon Hopkins “was dangling from the limb of a large sycamore that stood upon the bank of the river.”
After viewing the church marker, I scrambled my way down to the well sign-posted spring, which on arrival showed a bare trickle of water. Lawrence sat in his pickup above me (see the accompanying picture) and we yelled back and forth for about fifteen minutes.
All of a sudden I looked down to see a great burst of water rushing out at about 250-gallons per second. The Ebbing Spring had flowed while I was watching.
A half an hour later the spring was still flowing, and we were both getting hungry.
We celebrated by eating lunch at the El Campestre Mexican restaurant at the east end of Chilhowie right across from the American Indian burial ground beside the Chilhowie High School.
Jim Glanville is a retired chemist living in Blacksburg. He has been publishing and lecturing for more than a decade about the history of Southwest Virginia.