The U.S. Forest Service says 10 manmade dams in Silverado Canyon will need to be demolished to eliminate public safety hazards and possibly allow steelhead trout and other endangered species to reestablish in the habitat.
But some Silverado Canyon residents say they will form a human barrier to stop the demolition of the rock and mortar dams, some of which date back to the 1930s.
Hikers say removing the dams would also erase history. The local swimming holes have become an institution for those willing to trek a mile or so along maple springs road.
"When I was kid I used to go back here all the time," said hiker Hunter Chadwick. "I live in Coto (de Caza) and I go behind the trails back there all the time and it's such a nice reminder of how things used to be."
The dams are scattered through Silverado, Holy Jim and Trabuco canyons. A total of 81 dams are targeted for removal by the end of April.
Marines from Camp Pendleton will use explosives to tear them down.