SPRINGTOWN - Going with her dog Sue to check on her orchard in the early dawn hours of March 2, Karee Barrett was shocked to discover a new feature in her backyard, about 100 feet from her house, that wasn't there the day before - a sinkhole, 9-10 feet deep and about 35 feet wide, had opened up, revealing layers of soil and rock and with water moving through its bottom into an apparent small underground channel.

"I came close to stepping into it," Karee said of her discovery of the sinkhole behind her house, located at 17575 Aubrey Long Road, on March 2.

Preston and Karee Barrett purchased and remodeled their 1875 home (with a 1920s addition) in Springtown because it is adjacent to Big Spring, a large spring yielding more than 3 million gallons of water per day and the spring from which the town derives its name.

The spring fills a large pool on the west side of their home in which trout and other fish swim in the clear, cool water. The water leaves the pool in two channels which are major tributaries of Flint Creek.

While sinkholes may open up for a variety of reasons, the Barretts think roadwork done on Aubrey Long Road near the new bridge, to prepare that part of the road for paving, is likely the cause.

When Benton County road crews, on Feb. 15, were using a compacting machine on the gravel road which runs to the west of their home and close to Big Spring, it shook their home, Karee said. Looking into the large spring-fed pool just below their front porch, Karee said the usually clear waters were pulsating with clouded waters from the springs following the road work.

The gas company had to come out and repair a leaking gas line in Springtown, too, which the Barretts say likely ruptured because of the road-work. That meant more trucks and digging in the area, they said.

Then, on the morning of March 2, the sinkhole was discovered. In addition to the deep hole, large cracks and sunken ground continue east of the sinkhole.

University of Arkansas professor and hydrologist John Van Brahana examined the new sinkhole and, in a written assessment, suggested the heavy roadwork was a likely cause.

Benton County Judge Bob Clinard isn't so sure but hinted at the possibility the county could be responsible for filling in the sinkhole if the roadwork was the cause. He questioned whether the roadwork could have caused the sinkhole because the sinkhole is about 160 feet away from the road.

Springtown’s mayor, Paul Lemke, said the start of the sinkhole was there prior to the roadwork being done and can be seen on the Benton County GIS aerial photographs, online, which were taken prior to March 2 and the roadwork in February.

Lemke called the sinkhole a non-issue for the city or the county, saying it is “ludicrous” to blame the city or county for the formation of the sinkhole.

According to U.S. Geological Servey, sinkholes are a “localized collapse of the land surface usually due to erosion of the underlying materials” over time and most commonly occur in karst areas. The Barrett property is located above underground channels of water which join under their property and are tributaries of Flint Creek.

Other sinkholes have opened up on the Barrett property in the past, but most are much smaller and have been filled in. A large open sinkhole lies just to the east of the Barrett home but has been there for many years, the Barretts said.

Though their renovated two-story frame home shook when road compaction work was being completed, the Barretts felt pretty confident their home was not in danger because it is situated on bedrock, approximately 20 feet thick, Preston said. Cave divers who entered the spring from the pool beside their home have confirmed this, Preston explained.

The Barretts weren't sure how soon the sinkhole would be fixed, but said Van Brahana had told them it should be filled in with rock and gravel to allow the water from the underground streams which converge at the springs to continue to flow.

The Barretts were involved in a legal challenge with the town of Springtown when plans were formulated for a new bridge to replace a broken down low-water bridge over Flint Creek on Aubrey Long Road.

According to Preston Barrett, they offered the town land for the bridge and a road farther from the spring in order to preserve the spring and the underground caves and channels which feed it. Instead, the town condemned land and built its new bridge next to the old one and connected to the existing Aubrey Long Road.

News, Pages 1 on 03/27/2013