Porter Ranch Grading Plan Biggest Ever : Developer Wants to Move 40 Million Cubic Yards

A plan to develop 1,300 hilly acres in Porter Ranch calls for moving enough earth to fill the Rose Bowl about 50 times.

The developer of the $2-billion residential and commercial project estimates that 40 million cubic yards of earth must be graded during a 20-year construction period.

Los Angeles city officials say they have not kept a running total of grading approved in recent history, but they cannot remember a single project in the city with more grading than proposed in Porter Ranch.

“Nobody remembers anything in terms of grading on that scale,” said Frank Orbin, assistant chief of the city Department of Building and Safety’s grading division. “Not even close to that size.”

“We’re certainly up there,” Paul Clarke, spokesman for Porter Ranch Development Co., said about the huge amount of grading proposed.

Some critics of the development proposal say the grading and reshaping of the hills north of the Simi Valley Freeway are excessive. But Clarke noted that existing Los Angeles zoning law allows home construction that would result in substantial grading anyway.

Least Controversial Segment

The least controversial part of the Porter Ranch proposal is development of single-family houses, and that portion of the plan alone accounts for about 80% of the project’s estimated grading, according to the developer’s environmental impact report.

The development firm, run by Beverly Hills builder Nathan Shapell, wants to build 2,195 single-family houses, 800 multifamily housing units and 7.5 million square feet of commercial space in the hilly Porter Ranch area of Chatsworth. City Councilman Hal Bernson, who represents the area, has recommended reducing the commercial area to about 6 million square feet and adding 400 multifamily housing units.

The Los Angeles Planning Commission is scheduled to consider the plan Thursday, although the panel is awaiting a decision from the city attorney’s office on whether two members have a conflict of interest that would bar the commission from hearing the matter.

If the commission cannot hear the application, the Board of Referred Powers, which is made up of City Council members, would have to make recommendations on the plan to the full council.

To comprehend the amount of grading proposed for the Porter Ranch project, consider how much soil it would take to fill the Rose Bowl. Since the facility has a volume of about 814,000 cubic yards, according to the city of Pasadena, the amount of earth to be graded at Porter Ranch would fill the stadium about 50 times.

Or consider the amount of concrete used to build Hoover Dam in Nevada--3.25 million cubic yards. The amount of earth to be graded in Porter Ranch would be about 12 times that amount.

The 40 million cubic yards to be graded, if massed into a giant cube, would be 1,026 feet high. By comparison, City Hall is about 450 feet high.

Workers operating 100 bulldozers eight hours a day, five days a week would need at least two years to grade 40 million cubic yards, said Frank Byron, an engineer with McCoy Construction Co., a Calabasas firm that specializes in grading.

Clarke has described the project as the largest in the city’s history by one landowner on one piece of land. The elevation of the hilly site ranges from 1,150 to 1,850 feet above sea level.

The grading is described in the project’s environmental impact report as “cut and fill.” “Cut” refers to the taking of land off hilltops, and “fill” refers to the movement of that earth into valleys. In other words, little or no earth is removed from the site, which becomes more level.

Hillside Development

The grading proposed for Porter Ranch would take place over the life of the project, development company officials said. And the environmental impact report points out that far smaller hillside developments in Los Angeles have resulted in moving more earth per acre or per home than is proposed in Porter Ranch.

For example, in the Santa Monica Mountains, the 117-acre Bel-Air Crest Estates project resulted in 6.7 million cubic yards of grading, or about 57,000 per acre. The grading proposed for Porter Ranch is about 30,000 cubic yards per acre.

With any project, heavy grading can become necessary because housing demand and the high cost of land prompt developers to make projects as dense as possible, said Brian Heller, an Agoura Hills builder.

Building more homes means doing more grading, Heller said. “If the land prices hadn’t escalated so much and demand hadn’t been so high, they could have built five-acre lots” in Porter Ranch, he said.

In Orange County, McCoy Construction recently completed grading 56 million cubic yards for a 3,500-home project in the San Clemente area, Byron said. The original estimate was 30 million cubic yards, but buttressing the project to prevent landslides resulted in nearly twice as much grading, he said.

Clarke, the Porter Ranch spokesman, noted that the total amount of grading in the past 20 years for the 5,000 existing homes in the Porter Ranch area of Northridge probably exceeds 40 million cubic yards, although the homes were not approved as a single project.

Sheer Amount

Still, the sheer amount of grading has drawn criticism from some opponents of the project.

“There won’t be anything left of nature when they get through,” said Jan Hinkston, founder of the Santa Susana Mountain Park Assn. “It’s too much of an impact.”

“Obviously 40 million cubic yards is egregiously too much,” said Robert Birch, a spokesman for the PRIDE residents group, which opposes the project.

The developer’s environmental impact report said the grading effects would be minimal because of various measures to control erosion and prevent landslides. But the report also addresses how the project’s reshaping of hills would affect the visual appearance of the area.

“Development of the specific plan area would permanently alter the visual character of the site from surrounding areas,” the report said. “Views of existing undeveloped rolling hills would be changed to views of residential and commercial development and landscaping with some open space remaining.”

The Big Dig City Hall gives some perspective to the amount of soil that would be moved at Porter Ranch. The development calls for an estimated 40 million cubic yard (a cube 1,026 ft. on all sides of grading during the 20-year construction period. It is the largest total amount for any Los Angeles project in recent memory, although builders of smaller hillside projects in the city have graded more per acre or per housing unit. The total amount of earth that would be moved in Porter Ranch is about 50 times the volume of the Rose Bowl and 12 times the volume of concrete in the Hoover Dam. A fleet of 100 bulldozers would take at least two years to complete the job.