Army Corps of Engineers clear-cuts lush habitat in Valley An area that just a week ago was lush habitat on the Sepulveda Basin's wild side, home to one of the most diverse bird populations in Southern California, has been reduced to dirt and broken limbs - by the U.S. Army Corps of Engineers. Audubon Society members stumbled upon the barren landscape last weekend during their annual Christmas bird count. Now, they are calling for an investigation into the loss of about 43 acres of cottonwood and willow groves, undergrowth and marshes that had maintained a rich inventory of mammals, reptiles and 250 species of birds. Much of the area's vegetation had been planted in the 1980s, part of an Army Corps project that turned that portion of the Los Angeles River flood plain into a designated wildlife preserve. Tramping through the mud Friday, botanist Ellen Zunino - who was among hundreds of volunteers who planted willows, coyote brush, mule fat and elderberry trees in the area - was engulfed by anger, sadness and disbelief. I'm heartbroken. I was so proud of our work," the 66-year-old said, taking a deep breath. "I don't see any of the usual signs of preparation for a job like this, such as marked trees or colored flags," Zunino added. It seems haphazard and mean-spirited, almost as though someone was taking revenge on the habitat. In 2010, the preserve had been reclassified as a "vegetation management area" - with a new five-year mission of replacing trees and shrubs with native grasses to improve access for Army Corps staffers, increase public safety and discourage crime in an area plagued by sex-for-drugs encampments. The Army Corps declared that an environmental impact report on the effort was not necessary because it would not significantly disturb wildlife and habitat. By Friday, however, nearly all of the vegetation - native and non-native - had been removed. Decomposed granite trails, signs, stone structures and other improvements bought and installed with public money had been plowed under. In an interview, Army Corps Deputy District Cmdr. Alexander Deraney acknowledged that "somehow, we did not clearly communicate" to environmentalists and community groups the revised plan for the area 17 miles northwest of downtown Los Angeles. He added that the corps would "make the process more transparent in the future." But Kris Ohlenkamp, conservation chairman of the San Fernando Valley Audubon Society, asserted that the corps had misrepresented its intent all along. Walking Friday through what once had been a migratory stop for some of the rarest birds in the state - scissor-tailed flycatchers, yellow-billed cuckoos, least Bell's vireos, rose-breasted grosbeaks - Ohlenkamp said: "We knew that the corps had a new vision for this area, but we never thought it would ever come to this." Frequent catastrophic floods prompted civic leaders in the 1930s to transform the river into a flood-control channel. Nearly the entire 51-mile river bottom was sheathed in concrete, except in a few spots such as the Sepulveda Basin. Over the decades, awareness of the river's recreational potential grew. And with pressure from environmental groups, Los Angeles County and corps officials in the 1980s made major changes. The waterway and surrounding flood plain were slowly transformed into a greenbelt of parks, trees and bike paths, courtesy of bond measures approved by voters. Then in 2010, the Environmental Protection Agency deemed the entire river to be navigable and therefore subject to protections under of the Clean Water Act. A year ago, Army Corps of Engineers District Cmdr. Col. Mark Toy issued a license allowing the Los Angeles Conservation Corps to operate a paddle-boat program in the Sepulveda Basin, along a 1.5-mile stretch of river shaded by trees teeming with herons, egrets and cormorants. This summer, paying customers will disembark a hundred yards from the corps' recent clear-cuts. "Environmental stewardship is critical for us," Deraney said. But assuring public safety and access to infrastructure designed to deal with flooding are paramount. As he spoke, a Cooper's hawk swooped down and landed on a nearby tree stump.