Re "Santa Ana River: Let It Flow, or Let It Grow?" Nov. 3: Dredging the Santa Ana River and dumping any part of the spoils at sea is a very bad idea. All of the accumulated sediment in the riverbed is en route to the coast. Most of it is sand, and none of that sand should be wasted by dumping any part of it at sea, as proposed by the U.S. Army Corps of Engineers.
If dredging must be done, the sediment should be extracted over an extended period of time, which would allow for the spoils to be gradually placed on the beaches at Newport, Huntington, Seal and Surfside. With Seven Oaks dam in the San Bernardino Mountains, numerous other flood-control dams and the mining of sand and gravel from the bed of the river and its tributaries, the beaches have steadily been deprived of sand nourishment. Don't make the situation any worse by wasting the sand from the lower Santa Ana riverbed.
The only time sand is moved to the coast is by flooding rivers. Without flood waters, the sand in the riverbeds does not move. This creates a big conflict for the corps: It does everything it can to prevent flood damage, but flood waters move sand to the coast -- and the sand builds berms at the coast, which protect coastal property. The waves attack our sand-diminished beaches and destroy coastal property. Then the corps comes to the rescue and builds groins, etc., to protect the coastal property on the beaches. This is how the corps has managed to keep its work schedule so full.
Ivan P. Colburn
Geology Professor Emeritus
Dept. of Geological Studies
CSU, Los Angeles