New 101-405 ramp could cut traffic -- and wildlife

Expanding one of the nation’s busiest freeway interchanges won’t make life easier for some weary commuters.

A new ramp proposed for the 101-405 interchange in Sherman Oaks would destroy part of a wildlife reserve in the Sepulveda Basin that provides a rare resting place for migrating Canada geese, environmentalists say.

“We’ve trained the geese to come here for 20 years and forage in grasses we planted,” said Steve Hartman, a volunteer with the California Native Plant Society. “Are they going to come one year and it will be a dirt construction site?”

The project pits one of the San Fernando Valley’s last swaths of undisturbed open space against traffic improvements designed to ease congestion on one of the most crowded freeway interchanges in the nation.

The connector is ranked among the state’s most dangerous and delay-prone interchanges, routinely carrying more vehicles than it was designed to handle and often causing bottlenecks on the southbound San Diego Freeway. The exit from the southbound San Diego Freeway to the northbound Ventura Freeway (which actually runs west) is used by about 25,000 vehicles each day.

But several multimillion-dollar proposals to redesign the interchange call for building a new ramp in the southeast corner of a 225-acre wildlife reserve that Los Angeles city officials and environmentalists have spent decades turning into a haven for native plants and more than 200 varieties of birds.

The Sepulveda Basin Wildlife Reserve, bisected by a creek lined with large cottonwoods, contains a small lake and grasslands, considered some of the Valley’s best hunting grounds for birds of prey. Oaks, fruit-bearing bushes and other plant life are just now maturing, attracting birds that haven’t visited the region in years, ornithologists say.

“We’ve put 30 years of work and sweat into it,” said Kris Ohlenkamp, who has spent decades rehabilitating the reserve and estimates he has taken thousands of children on walks there. “This wildlife area is part of the San Fernando Valley’s culture. It’s part of everyone’s lives here.”

But transportation experts argue that the connector must be reworked to ease traffic headaches and to ensure that the interchange can handle future increases.

“This is one of the busier connectors we have in the entire country,” said Aziz Elattar, office chief of Caltrans’ environmental planning division. “Everyone involved in transportation agrees it’s an important project.”

The California Department of Transportation has been studying how to rework the interchange for years. But a final decision is near, with public comments due by Wednesday on a 288-page environmental assessment that analyzes four options, including doing nothing. The agency plans to choose by the end of June.

The existing single-lane connector ramp requires drivers to weave in and out of lanes to access various roads. All three proposals call for replacing that interchange with a two-lane overpass designed to increase traffic speeds from 20 to 50 mph. That bridge would be built over a spillway that’s part of the Sepulveda Dam.

One of the proposals would eliminate access to the Ventura Freeway from Burbank Boulevard and wouldn’t require construction on the wildlife reserve. The other two call for restructuring access to both freeways from Burbank Boulevard by building a looped ramp on several acres in the reserve’s southeast corner. The proposals range in price from $86 million to $117 million. Funding hasn’t been approved.

Caltrans studies suggest construction would not cause long-term damage to the wildlife reserve.

“Although there may be temporary disruptions or impacts during the construction phase, there are not anticipated to be any permanent direct or indirect impacts to these species resulting from this project,” Caltrans analysts wrote.

Environmentalists disagree, saying increased noise from a new ramp in the reserve would disturb sensitive birds and could diminish the habitat’s draw for birders who routinely record the comings and goings of many species and for students who travel to the dam to learn about nature.

“The big problem is the cumulative loss of acreage,” said Kimball Garrett, ornithology collections manager at the Natural History Museum of Los Angeles County.

“There’s very good data that show as you whittle away the acreage of habitat, it becomes able to support a lot less wildlife,” Garrett said.

An official at the Los Angeles Department of Recreation and Parks, which manages the Sepulveda Basin, said he was concerned about the project.

“Many volunteers, the city and the U.S. Army Corps have worked for many years to develop the wildlife area,” said Kevin Regan, the department’s assistant general manager. “It would be a difficult thing to have any damage, or destruction, or loss of that open space.”

--

jennifer.oldham@latimes.com