Thursday, April 10, 2014

Surfers Point - cobble berm monitoring

One of the innovative components of the Surfers Point Managed Shoreline Retreat Project is the application of a buried cobble berm to provide shoreline protection for the bike path and parking lot that were moved inland.  The berm is 8 feet thick and approximately 80 feet wide and is buried beneath constructed and revegetated sand dunes.

As a reminder of why this project was constructed, here is a photo of the bike path in 1994:

Historically, the area of greatest erosion is immediately downcoast of the Ventura River levee, which acts as a groin in blocking littoral (along shore) sand transport.  This area continues to see dramatic seasonal changes as the beach comes and goes with changing wave climate.  The typical summer beach looks like this:

 While currently the winter beach looks like this:

So depending on when you visit the site, the "toe" of the cobble berm may or may not be evident.

The following is a collection of photos taken from the Ventura River Levee at the west end of the project site looking back towards the beach restoration area.  This series of photos shows the excavation of the parking lot and the importation of cobble and sand to create the buried cobble berm.    It also illustrates the seasonal changes and the evolution of the cobble berm in response to the changing wave climate and sand supply.  Note that the spur groin in the right foreground can be almost buried with sand in the summer months.

We will continue to photo document this aspect of the project to demonstrate the effectiveness of the cobble berm to adapt to future changes.