Playa Vista: The area has already been preserved, and the studio site has been used by heavy industry since the 1930s.

If I were the open space and preservation czar of Los Angeles County with an unlimited budget, I would consider buying some Playa Vista land intended for offices and develop it instead for active public recreation.

If I were czar on a limited budget, I would acquire habitats of higher quality and greater biodiversity--Big Tujunga Wash, for example, and some of the many threatened riparian woodlands in the Santa Monica Mountains.

In neither case would I worry about “saving” the Ballona Wetlands. Why? It’s already being done. The Army Corps of Engineers and the Coastal Commission determined that there are between 180 and 190 acres of wetlands on the Playa Vista site. Public agencies (not developers) made the delineation when regulations were more favorable to wetland preservation. All of the viable wetlands are, under current proposals, included within a 340-acre habitat preserve. Less than 25 acres of “incidental wetlands,” isolated patches (mostly man-made) with little or no habitat value, are proposed to be filled.

If the restoration does not work as intended, monitoring conditions provide for corrections. If any of the more than 30,000 container specimens of native plants scheduled to be planted do not survive, they must be replaced.

Critics of Playa Vista (operating under the umbrella “Citizens to Save All of Ballona”) argue that most or all of the 1,000-plus acre site should be open space; that most of it is occupied by wetlands or uplands critical to the wetlands’ survival; and that the project--specifically the DreamWorks SKG movie studio complex--threatens habitat values. They say the riparian corridor will carry polluted water and that the freshwater marsh is just a retention basin.

Is such criticism valid? The group’s “589 Reasons to Save All of Ballona” include the domestic dog and cat, Norway rat, European red fox, starling, Algerian ivy, Italian ryegrass, Japanese pittosporum, pampas grass and castor bean. These species, as well as almost 200 others on the list, are escapees from nearby neighborhoods and leftovers from half a century of industrial and agricultural disruption. They cannot be part of the salvation of a natural Ballona ecosystem because they are a direct threat to its health and vitality. Sentimentalists may wish to preserve these destructive species; environmentalists spend their weekends on eradication and restoration campaigns.

All marshes are retention basins, after all, and all wetlands cleanse the waters that feed them. Even in its degraded state, Ballona is doing this right now and will do it better as restoration proceeds. Groundwater treated on site, passing into Ballona, is cleaner than preproject water. Catch basins on the developed portion of the site and others to be installed off-site will trap oil and grease. The claim that DreamWorks or other elements of Playa Vista will degrade the wetlands and Santa Monica Bay is baseless.

So is the argument that land east of Lincoln Boulevard is suitable for restoration to a natural state. The DreamWorks site has been in heavy industrial use since the 1930s. It was a major employment center for the defense and aerospace industries, where, during World War II, the Spruce Goose was built and stored. Many of the vast hangars and support buildings in which history was made--1.7 million square feet of structure--still stand.

If I were open space and preservation czar, I would try to find a creative reuse for these historic buildings so they would not be lost to redevelopment. Ideally, such a use would produce no impacts more serious than the complex originally planned. Ideally, it would generate well-paying jobs to replace jobs lost to defense downsizing. Ideally, it would improve the land-use mix by providing a significant industrial component.

DreamWorks accomplishes all of these goals while setting aside 14% of its acreage as aesthetic (not natural) open space.

The battle to save Ballona Wetlands has been won. It was won before DreamWorks decided to move to Playa Vista. The wetlands are threatened now not by Playa Vista, but by well-intentioned opponents who chain themselves to bulldozers scheduled to remove invasive plants and to deepen water channels as part of the wetlands restoration. Meanwhile, other worthy environmental battles are lost for lack of committed and informed opposition, while energy, money and good intentions are squandered on a struggle not to save the wetlands, but to stop the project that assures (and funds) their restoration. There may be reasons to oppose Playa Vista, but saving natural habitat is not among them.