On the surface, Malibu Lagoon would seem a shining example of a restored wetland, a rarity along Southern California's built-up coastline.
In an estuary that was once filled with dirt to create baseball diamonds, snowy egrets and black-crowned night herons now hunt for fish along the grass-covered banks of tidal channels, while sparrows and red-winged blackbirds perch on tule reeds swaying gently in the sea breeze.
But beneath all that are stagnant, polluted waterways with steep banks so poorly constructed when the lagoon was restored that state parks officials say they must be drained, dredged and rebuilt to meet even basic water quality standards.
The Coastal Commission will consider on Wednesday a $7-million fix that would temporarily drain a 12-acre section of the lagoon to re-contour it, remove sediment and replant its banks with native plants in order to improve water circulation and ecological health.
The plan is more than a decade in the making and has sparked a rare public rift among environmentalists.
Although most conservation groups support the project and the coastal panel's staff has recommended approval, some activists say the heavy grading, use of construction equipment and ripping out of vegetation is heavy-handed and would essentially destroy the habitat in order to save it.
"If it was a tabula rasa, like a parking lot, that would be different," said Marcia Hanscom of the Wetlands Defense Fund. "But this is a thriving ecosystem."
Backers of the project say that's simply not true. The lagoon, they say, is degraded and suffers from chronically low oxygen levels, polluted sediment and such poor water quality that it has been listed by the state as "impaired" since 1992.
"While we think it's much better than a baseball diamond, it's just not functioning very well ecologically," said Mark Abramson of the Santa Monica Bay Restoration Commission, the project manager for the restoration. "It has major, major problems."
If the restoration project is approved, workers would start next year to grade the lagoon's banks to make them lower, scoop out more than 1,000 dump-truck loads of sediment, build a single meandering channel more suited to tidal ebb and flow and plant thousands of plants appropriate for a salt marsh.
Crews would also remove a pathway that cuts across the marsh to the beach and is blamed for restricting the flow of water in and out of the lagoon.
After some recovery time, the result would be an unobstructed wetland regularly cleansed by the tide, one that would support a more diverse assortment of fish, plants and invertebrates and even improve water quality at nearby Surfrider Beach, supporters say.
Those in favor of the project, including Santa Monica Baykeeper, the Malibu Surfing Assn. and Heal the Bay, don't dispute that dredging and grading will take a toll on wildlife in the short term. But that hardship is worth the long-term environmental gain, they said, an opportunity to finish a job that began more than 25 years ago when the restored wetland was first carved out.
Activists with the Wetlands Defense Fund, however, say state regulators should consider a more gentle restoration that would nix the bulldozers and instead use community groups to remove polluted sediment and replace nonnative plants.
In that scenario, the layout of the lagoon would remain as it is, a notion other conservationists call pointless because it wouldn't bring enough tidal water to cleanse the habitat of pollutants swept in by Malibu Creek.
The city of Malibu supports the project, though in an Oct. 7 letter to the commission, City Manager Jim Thorsen said the city "still has strong concerns" about the effect on water quality in the area during and immediately after construction.
Residents of the Malibu Colony, a gated community that neighbors the lagoon, have also raised concerns about the project's effect on their security and privacy because it would remove an access way to Surfrider Beach and consolidate foot traffic on a path behind about a dozen of their backyards.
"My neighbors and I are not opposed to cleaning up the creek and lagoon if the scientists say it will improve water quality," said Geoffrey Nathanson, a 49-year resident and Malibu Colony Assn. board member. "It's the massive dredging project and the total destruction of the lagoon as it's proposed that's the problem. Do we have to destroy the wetland in order to save it?"
Richard Ambrose, director of UCLA's environmental science and engineering program, who served as an advisor for the project, said concerns about the project "stem from the fact that they treasure the value of the lagoon the way it is now."
Ambrose, however, said he believes that starting from scratch to correct the wetland's limitations is what has to be done to ensure a more lasting and healthy future.
The fish and birds, he said, will re-colonize, and the plants may take a bit longer to fill out. But in the end, he said, "this a place where we will be able to get a much richer salt marsh habitat."