Finding the source: Where does Roaring River come from?
New dye project aims to trace river source area
At the coordinates 36.59, -93.83, one can find arguably the most wonderful part of Roaring River State Park — the spring where the river is born.
The Roaring River Spring emerges from the base of a limestone cliff with an average daily flow of 20.4 million gallons, at an average temperature of 57 degrees. A smaller spring at the top of the cliff creates the waterfall, which splashes into the the main pool.
“The pool is only about 10 feet across but if you were to dive in (not recommended), you’d find yourself in a large cavern that’s recently been explored down to a depth of 223 feet,” said Tommy Hornbeck, with the Universities Space Research Association, . “This cavern follows a displaced fault line hollowed out by the action of moving groundwater.”
Hornbeck said with more than 3,000 known springs, the state of Missouri has large areas of karst topography where the movement of groundwater has led to the formation of losing streams, caves, springs and sinkholes.
“The bedrock of these areas is predominantly dolomite and limestone,” he said. “Rainwater mixes with carbon dioxide and forms a weak carbonic acid that creeps through cracks and fractures in the bedrock gradually carving out underground rivers that on occasion can rise to the surface forming the springs.”
A common way to find the source of a spring’s water is dye testing.
“[For Roaring River], fluorescent dye was injected into a sinkhole on the prairie a few miles south of Cassville,” Hornbeck said. “Later, the dye reappeared at Roaring River Spring, having moved some 6 miles horizontally and 395 feet downward, to the surface of the Roaring River Spring, in eight days. The spring water flows into one of the oldest fish hatcheries in the state. This hatchery produces and stocks more than 250,000 rainbow trout each year into local streams, most of the fish going into the Roaring River itself.”
Tim Smith, with the Roaring River Nature Center, said the water from the spring comes along a small fault line, and the spring is formed along a joint in the dolomite rock.
“Some of the water comes off the Washburn prairie between Cassville and Washburn,” he said. “[A new dye project underway] aims to determine the entire recharge area. It’s in cooperation with the Geology Land Survey, and another organization is working with them and Missouri State Parks.”
Smith said the original study, done in the early 1990s, did not show that many areas, and the new one is looking to show a larger area. The dye is non-toxic and will not harm wildlife or any water supplies.
“Rainwater goes into the underground reservoir, and we’re trying to find how it flows, like through caves or sinkholes, and if it comes out in the spring or someplace else,” he said. “This will be valuable information if there is some type of event, like a contaminant in the recharge area. We will know if it will come through the spring and how long it will take to get there, so we’ll know how long we have to put a plan in place.”
Smith said the new information will not help with floods prediction, but could tell the hatchery staff what the spring level may be after a rain event.
“Certain areas may take 10 days to reach the spring, and others may be only two or three days,” Smith said.
The first dyes have been placed, and Smith said the whole project will span one-and-a-half to two years.
“There are charcoal packets placed in different locations, and they will absorb the dye,” he said. “Then, the charcoal will be analyzed and you can tell if there is dye on them. The charcoal is in five locations right now, and if it doesn’t show up there, it may be in a different hollow.”
According to exploresouthernhistory.com, Roaring River Spring is the 20th largest spring in Missouri, and the river eventually empties into Table Rock Lake.
“The stream rising at Roaring River Spring has been an important landmark since well before the Civil War,” the site said. “Native Americans frequented the area for thousands of years before the arrival of the first pioneers, taking advantage of the rich natural setting surrounding the spring and river. Early settlers of the region used the stream to power mills for use in grinding grain and sawing lumber.”