Ecologically Sensitive Areas Show Damage Since ‘76, Report Shows

An environmental consultant hired by Los Angeles County to review sensitive ecological areas found many of them to have been significantly damaged since they were last studied in 1976, according to a report released to the county Regional Planning Commission.

The consultant, Michael Brandman Associates, said that without drastic changes in county development policies and restriction of access to the areas by humans and grazing animals, the very qualities that led county planners to select the areas for protection--ranging from rare fish to oak forests--will be lost.

Among the recommendations included in the report are added restrictions on development around the county-designated Significant Ecological Areas to prevent pollution of water runoff into the areas, buffer zones of native plants on the areas’ perimeters and expansion of some of the areas to improve the potential for wildlife survival.

In the case of one relatively pristine area near Malibu, the report suggested that a homeless encampment--which it said presents a threat to vegetation and wildlife that have contact with litter and human waste--should be moved.

Most of the ecological areas are under private ownership and were never intended to be kept completely development-free. However, the consultant said that the county should strive to turn many of them into nature preserves by persuading builders to dedicate them as permanent open space in return for county permission to build more houses elsewhere.

The report included seven areas: three in the Santa Monica Mountains, one near the San Fernando Valley, two in the San Gabriel Valley and one near Diamond Bar. It is the first phase of a planned review of all 61 Significant Ecological Areas requested by supervisors in the wake of repeated complaints from environmentalists.

Environmentalists say the report confirms their worst fears, yet gives them hope that the areas can be saved. Jill Swift, parks chairwoman for the Angeles Chapter of the Sierra Club, said the most important ecological areas should be purchased by the county and preserved through inclusion in a park bond act proposed for the November ballot.

“All of those that are remaining that have endangered or rare species . . . should be purchased and set aside because once those are gone, that’s it,” Swift said. “We’ve got to draw the line right now.”

Joseph T. Edmiston, executive director of the Santa Monica Mountains Conservancy, said the consultant’s proposal for creating a county policy to trade open space in the ecological areas for density elsewhere is “an innovative idea, especially if the county were to fairly administrate that . . . if everybody were included.”

Edmiston said that when the county has required developers to set land aside for protection in the past, it has done so on a case-by-case basis, not as a overall policy.

The three SEAs in the Santa Monica Mountains were:

* Tuna Canyon. A steep and rocky region north of Pacific Coast Highway and just west of Topanga Canyon was designated significant because it was considered among the last drainage areas in the Santa Monica Mountains undisturbed by development. The canyon’s streams provided water sources for wild animals and temporary homes to migratory songbirds and waterfowl.

Some development has occurred since then--scattered through sections of the SEA--but the report said the greatest threat to the Tuna Canyon SEA comes from a homeless encampment in the woodland near Pacific Coast Highway.

“The lack of controls over water quality associated with such encampments will adversely affect the health of the vegetation and wildlife exposed to human waste and rubbish,” the consultant wrote.

A wide variety of birds and mammals ranging from possums to deer and mountain lions continue to live there, which the report attributed to the efforts of the National Park Service and the Santa Monica Mountains Conservancy, and to the rocky, steep terrain.

Tuna Canyon was described by the consultant as ideal for “density transfers,” where developers would be allowed to increase building density on nearby parcels in return for setting aside twice as much land as permanent open space within the SEA.

* Cold Creek. An area of the Santa Monica Mountains virtually surrounded by federal and state parkland. It was designated sensitive because it contains a sandstone formation known as a “bench” and a perennial stream, Cold Creek, which supports what was described, in 1976, as “a showplace for native vegetation.”

Since then, some areas have been taken over by non-native grasses because of clearing for construction or fire prevention, according to the report. However, this area also was in found to be in better shape than many, which the consultant attributed to the efforts of the private Mountains Restoration Trust and the Santa Monica Mountains Conservancy, a state park acquisition agency.

However, the consultant warned that there is potential for large-scale development in the southern part of the SEA and that this should be discouraged. It recommended a buffer zone of native plants be established around any developments, that developers be required to contribute to riparian restoration programs, that human intrusion be discouraged with signs and that urban runoff be limited.

* Las Virgenes. A mountainous area east of Cornell Road, south of the Ventura Freeway and west of Liberty Canyon was designated significant for a variety of plant life common to the interior of Southern California, but rare in the Santa Monica Mountains. Those plants include a variety of juniper and a species of lily. During the 1976 study, there was no significant development in the area and it could be entered only by one dirt road.

The report found that since then, many of the area’s hillsides have been taken over by non-native grasses, evidence of grazing and human traffic from the neighborhoods that have sprung up nearby.

It recommended that this ecological area be expanded to the east and southeast to incorporate a possible freeway underpass for wildlife, proposed by Supervisor Ed Edelman, and a connection with Malibu Creek State Park. The Las Virgenes SEA also was described as ideal for the “density transfers,” where developers would be allowed to increase building density on nearby parcels in return for setting aside twice as much land as permanent open space within the ecological area.

It also recommended that annexations of the ecological area by nearby cities be discouraged because “this presents an opportunity for development of the SEA inconsistent to the unique biological resources currently protected by the county.” However, the nearest cities--Calabasas and Malibu--actually voted to incorporate largely in reaction to what was perceived as overly permissive county development policy.