LAKE COUNTY — The softened, eroded volcanic earth flanking the roadway caused cracks that appear like claw marks slashed across the asphalt.
The origins of the Manning Flat “canyon” located next to Highway 29 a mile and a half south of Kit”s Corner are debatable. But regardless of the origin, Cal-trans plans to re-route the highway in the near future to avoid the crack.
Known as “Lake County”s Grand Canyon” by locals, the flat field was purportedly dynamited by property owners in the late 19th century to solve a flooding problem, although some residents say it is a natural fault.
Cal-trans has worked to patch up the cracks for many years and plans to do a preventative maintenance project to repave the damaged sections next summer.
But that”s just to bide time. The real solution will come in four to five years when the entire highway will be moved almost two miles south to loop away from Manning Flat and make way for a four-lane expressway. This way, Cal-trans says, they can also avoid destruction of three types of endangered plants that grow in the area: Few-flowered navarretia, Lake County stonecrop, a plant endemic to Lake County, and Burke”s goldfields.
The Manning Flat area of the Highway has become a habitat for the Few-flowered navarretia, which only grows on disturbed earth, according to Lake County Public Works Director Gerry Shaul. “By putting in the highway we created a habitat for this plant, which requires us to re-route the road,” Shaul said.
According to the Sacramento Fish and Wildlife Office”s species account, the three plants are highly susceptible to trampling and destruction of their habitats, which are typically vernal pools and meadows. Few-flowered navarretia is an extremely rare plant believed to have only existed in Napa County. It thrives in volcanic ash and volcanic ash vernal pools.
Cal-trans public information officer Phil Frisbie Jr. says the “Lake 29 expressway project” is what the long-term fix will be to avoid the fissure and endangered plants. “I was told we were bypassing the area to avoid the plants and the fissure. The way it was described to me was that it is soft soil that keeps settling, so Cal-trans has to keep filling in the cracks as they develop. It”s been settling like that for years. They”re out there periodically patching up and paving over the area,” Frisbie said.
The project is currently in the draft and environmental report stage, and construction will likely start in the summer of 2012. The new road will span from milepost 23.8 (north of Kit”s Corner) eight miles south to milepost 31.6. An open house at Konocti Resort on the project was held Aug. 8 with more than 30 people showing up to see the displays.
According to Shaul, the “maybe myth or maybe true” story of the canyon begins when his ancestors first came to Lake County in the 1850s. He said that Manning Flat, a flattened hill above the canyon area, is the cauldron of a volcano. “Consequently the material in it is volcanic ash. The first Shaul that came married a Manning. They attempted to farm the land, but in the winter it was a lake. Manning decided to breach the natural dam to the north and get it to drain.” Shaul said the area had long been filled with water, and as such the trails and wagon train went around Manning Flat.
“They got a hold of some dynamite, and made the breach much more permanent. The downside is because the soil was so erodable; any time run-off ran through the breach, it ended up going down to Thurston Lake. That”s why it”s so milky all the time because the colloidal volcanic ash never settles out. I think it will continue to erode until you get into some type of igneous rock,” Shaul said.
According to Terry Knight, Record-Bee outdoors columnist, some long-time residents believe it is a natural fault. Cal-trans did not have any information about the true origins of the fissure. The Lake County historian appointed for the county could not be reached for comment.
“Some people who are in their late 60s said that”s a natural fault that was not put in there. Before the fault was there it used to be called a race track, because they raced horses there. The erosion is from the drainage,” Knight said.
Cal-trans nor Public Works could confirm when Highway 29 was built or whether the fissure was already there at that time.
“I think it (the fissure) happened before Highway 29 was put in there. But even in really heavy winter storms I”ve never seen much water go through there, just a little tiny stream,” Knight said.
Contact Elizabeth Wilson at ewilson@record-bee.com.
