© 2008 Wendy Dager

U.S. Geological Survey photo of the 1995 La Conchita landslide.

When the California seaside community of La Conchita was devastated by a mudslide in 2005—resulting in 10 deaths and the destruction of 13 homes—there was plenty of blame to pass around. Television crews and newspaper reporters were in full force as residents expressed their anger, with many saying it was the fault of Ventura County government for not taking precautions to secure the dangerous hillside. But it wasn’t the first slide to strike the community in recent years; there’d been another in 1995. However, its history goes back much further than that: geologists say this area is part of the Rincon Mountain slide, which has been generating landslides for thousands of years.

“The topic of landslides is certainly an important issue,” said Paul Albright of S&S Seeds. “The problem is, people tend to focus on the drama of the moment, rather than on what’s happening in the long term in many other areas that require vegetative cover.”

While slope saturation is a leading cause of landslides, many of the geologic conditions (see chart) that contribute to landslides cannot be resolved by hydroseeding.

Landslide Causes Geological causes Weak or sensitive materials Weathered materials Sheared, jointed, or fissured materials Adversely oriented discontinuity (bedding, schistosity, fault, unconformity, contact, and so forth) Contrast in permeability and/or stiffness of materials Morphological causes Tectonic or volcanic uplift Glacial rebound Fluvial, wave, or glacial erosion of slope toe or lateral margins Subterranean erosion (solution, piping) Deposition loading slope or its crest Vegetation removal (by fire, drought) Thawing Freeze-and-thaw weathering Shrink-and-swell weathering Human causes Excavation of slope or its toe Loading of slope or its crest Drawdown (of reservoirs) Deforestation Irrigation Mining Artificial vibration Water leakage from utilities —From U.S. Department of the Interior, U.S. Geologic Survey, Fact Sheet 2004-3072, July 2004, http://pubs.usgs.gov/fs/2004/3072/fs-2004-3072.html

However, there are plenty of other locations that would benefit from seed and other products so as not to fall victim to surface erosion due to wind and rain.

Young sod production

“The cost of this erosion, while not as newsworthy as a landslide, is far greater and much more widespread,” said Paul. “It’s a slower progression, but it’s still devastating to the environment.”

At S&S Seeds, we’re continually striving to bring our customers the best in erosion control methods. We’ve conducted extensive studies to make sure our soil stabilization products match the industry’s Best Management Practices (See “Erosion Control Products Put to the Test,” Click here).

For information about seed mixes, bonded fiber matrices and more, call our experts at (805) 684-0436 or visit http://www.ssseeds.com. Our goal is to provide you with the best solutions for all your landscaping and erosion control needs.