Conservation organizations sued the Los Angeles County Board of Supervisors this week for approving the 1,300-acre Northlake housing development, which they say would pave over a pristine stream, degrade wildlife connectivity for local mountain lions and put people at greater risk of wildfires.

The suit, filed in Los Angeles County Superior Court, notes that the project area is designated by CalFire as a “very high fire hazard severity zone,” and makes reference to a resolution adopted by the supervisors in December 2018 acknowledging a “new era of threat from wildfires” driven in part by residential development in highly fire-prone areas.

“The horror and heartbreak of California’s last fire season showed why Northlake shouldn’t be built in this highly flammable area,” said J.P. Rose, an attorney at the Center for Biological Diversity. “County supervisors shouldn’t have approved this large-scale development in this fire-prone place. Sprawl projects like this one lead to lost lives, scorched homes and escalating firefighting costs, and they’re terrible for wildlife.”

The project dates all the way back to 1992. In September 2018, the supervisors voted 4-0 to move forward with approvals for the first phase. At that time, Supervisor Sheila Kuehl abstained from the vote, raising concerns about blocking the migration of mountain lions and other wildlife, as well as a plan to fill in a local creek that is a habitat for owls, toads and multiple bird species.

Supervisor Kathryn Barger, who represents the Fifth District where the development will be sited, stressed the need for affordable housing in the Antelope Valley.

“We must build 180,000 units per year to keep up with current demand, which is highly unlikely,” Barger said. “The main way we begin to tackle the affordability crisis in this county is to create more supply, and this project is a step in that direction.”

Barger said the project, which is expected to add 3,150 homes in two phases, plus office and retail space, would also spur additional investment in the area.

To address environmental impacts, the developer committed to set aside 10 percent of the housing units as affordable, build a public sports park and develop trails as part of the project’s preserved open space. The first phase of the project will build out 720 acres of the 1,330-acre site and parcels will be set aside for a school and community fire station.

“We took ownership of the project in 2013 and immediately started working to make the project smarter, greener, more sustainable, less dense and less impactful to the environment,” said John Arvin, a principal with NorthLake Associates LLC. “We have added solar energy and (electric vehicle) charging stations. We have added parks and trails and reclaimed water.”

Barger and Supervisors Janice Hahn, Hilda Solis and Mark Ridley-Thomas voted to issue final approvals on April 2.

The Santa Monica Mountains Conservancy, the Center for Biological Diversity and the Golden State Environmental Justice Alliance oppose the project. The conservation organizations raised their concerns in comment letters and public hearings with the county, claiming the project violates the California Environmental Quality Act.

An attorney for the developer countered said the site is not a wildlife corridor because the Golden State (5) Freeway and Castaic Lake are close enough to pose as barriers to wildlife movement in the area. He called the claims of environmentalists without merit.

While regional planners billed the project as walkable and the developer has agreed to privately fund a shuttle service to offsite employment, opponents said it was being built in an area with few jobs and would create long commutes.

“L.A. County has no business allowing new communities in isolated, undeveloped open space that would expose new residents to a high risk of wildfire,” said Ross Middlemiss, a legal fellow at the Center for Biological Diversity.