Monday, October 02, 2006
Photo: Surfing at Kelp Cove
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Clay Gantz
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Comments
The lack of an awareness of even basic geology for our area always amazes me. The lack of awareness of the negative effects of some kinds of development and other artificial activity in light of well-known geological factors compounds my amazement.
Sandy beaches are dynamic areas, in constant change due to a variety of interacting physical conditions and forces. It does not take years of technical education to get the basics distilled for us by coastal geologists. What are the kinds of beaches? On what kinds of shorelines are beaches found? What is sand? Where does the sand on beaches come from? How does the sand on beaches change with the interacting forces of seasons, storms, tides, waves, winds, currents, runoff from the land, etc.? How do beaches change with artificial impacts from impoundments on streams and rivers, hardscaping of coastal watersheds, bluff armoring, breakwaters and beach structures like groins, introduced vegetation, trampling and vehicles on beaches, blufftop development, etc.? What kinds of natural organisms live in and on beaches? These matters are all well understood in principle and are fortified with extensive examples.
The kinds of negative impacts caused by bluff armoring such as rip-rap and sea walls are not controversial. The impacts have been observed in dozens, even hundreds of varying situations on the California coast and in thousands of locations elsewhere. Anyone who walks beaches on the West coast of North America soon builds empirical knowledge of what geologists have studied and classified. The exact impacts of bluff armoring on any given beach will depend on the morphology of the coastline and the multiple forces in play at that location, but they are never positive in terms of retaining natural beach conditions, including the beach’s changing complement of sand. Changes to adjacent unarmored bluff due to bluff armoring are also well-documented and never positive in terms of retaining the natural rate of bluff erosion.
There is no mystery about the mistakes made by development and armoring on the soft bluffs of the midcoast. The negative impacts are clear. To continue such damaging behavior is irresponsible to the public that owns the shoreline up to the mean high tide line, to shoreline ecosystems, to taxpayers who are sometimes called on to bail out the mistakes, and to naive buyers of beautiful blufftop property.
Leonard, if you want an oceanside view house, only buy on hard, solid (not fractured by seismic activity) rock extending all the way into the ocean. There are good reasons why rocky points stick out farther into the ocean than low shorelines with dunes or soft bluffs. You won’t have a beach below your house unless it is a very small and probably inaccessible pocket beach, but that’s what one gives up for a relatively stable place adjacent to the ocean.
Carl May
The guy who lives in the red house is probably not too happy about the rip-rap his southern neighbor laid down. The “end effects” of the rip rap are seriously eroding the northern parcel. Nature will claim its due, eventually. The only question is who pays.