Santa Clara Valley Water District officials are taking swift action to control worsening erosion along Stevens Creek Trail. A large chunk of the paved path caved in over the last six weeks and now threatens the city's new trail detour.
In an Aug. 18 memo, water district staff recommended that interim CEO Norma Camacho declare an emergency, enabling the water district to skip the normal contracting process in order speed up the repair the damaged segment of Stevens Creek north of El Camino Real before the next rainy season, which officially begins on Oct. 15.
"Absent the emergency action, high flows in the creek coupled with saturation of the eroded embankment will likely hasten the already alarming rate of soil erosion," the memo said.
In January, heavy rainfall coupled with controlled releases from the Stevens Creek reservoir weakened the soil along a steep embankment between El Camino and Yuba Drive, causing a landslide about 180 feet in length, according to the memo. The immediate aftermath caused trees to tumble into the creek and left a 25-foot nearly vertical drop into the creek bed just inches from the edge of the trail.
Despite the reprieve from wet weather during the spring and summer months, conditions on the creek bank have gone from bad to worse. Erosion now has claimed a larger stretch of the creekside, and has widened enough to swallow up a 60-foot portion of the creek trail. Mountain View city staff told the water district earlier this month that soil loss along the trail now has the "potential" to erode the city's trail detour, which was completed in June and runs through the adjacent hotel property. Erosion could also undermine several nearby redwood trees, the memo said.
Aaron Grossman, executive director of the Friends of Steven Creek Trail, said the group is "very worried" about the worsening erosion, and that they have sent requests to the water district asking to expedite the repair work to stabilize what's left. Without some sort of intervention, he said, there won't be much creek bank left for a path.
"Things are going downhill fast," Grossman said "The wash-out left things in a very precarious situation, and we're worried that without fast intervention the land subsidence won't leave enough (room) for a trail there."
Geotechnical staff for the district found that without some sort of emergency repair work, more segments of the trail would likely collapse, posing an "imminent threat" to the public trail, the district's maintenance road and adjacent properties. The memo concedes that the worsening conditions on the creek bank in August were unexpected.
The announcement by the water district doesn't mean the trail will be restored and open to the public at an accelerated pace. The emergency declaration specifically calls for repairs to prevent erosion from progressing, and a larger capital project to restore the trail will kick off next year.
Although city staff voiced concerns about the temporary trail detour being affected by the erosion, the bypass remains open to the public. Public works staff will meet with the water district once repair plans are in place to figure out how it might impact trail users, according to Bruce Hurlburt, the city's parks and open space manager.
The request for an emergency declaration was approved by Interim CEO Camacho and went before the district board for review at its Aug. 22 meeting, according to a water district spokeswoman.