The Southern California Coastal Water Research Project recently released a report (pdf) detailing, "the characteristics of historical wetland habitat types and describ[ing] the historical form of major creeks in the Ballona Creek watershed." That's important because "the historical landscape of the Ballona Creek watershed [is] a 130-square-mile swath of land home to more than 1.2 million people that includes much of western Los Angeles, Beverly Hills, Inglewood, South Los Angeles, and the Baldwin Hills," according to KCET.
The report looks at the time between 1850 and 1890--after a geological event (read: earthquake) altered the path of the Los Angeles River, but before Los Angeles was developed. That period, right around the time California became a state, is particularly data rich (the SCCWRP used over 300 documents from 84 source institutions).
The researchers found that the historic Ballona Creek watershed included more than 14,000 acres of wetlands: "The Ballona watershed supported a great diversity of wetlands during the mid-late 19th century (figure es-1). The La Cienega wetlands and the Ballona Lagoon complex accounted for the majority of wetland area in the watershed. Various freshwater ponds, vernal pools, wet meadows, freshwater marshes and numerous springs were found throughout
the watershed. We mapped 174 unique wetland polygon features comprising 14,149 acres. The dominant wetland types included alkali meadow (35%), valley freshwater wet meadow (10%), valley freshwater marsh (10%), brackish to salt marsh/tidal marsh (9%), and alkali flats (8%)."
The report provides all this data because "The contemporary Ballona watershed represents unique opportunities for restoration planning," which, of course, are already playing out. At the end of January the Coastal Conservancy announced a $6.5 million grant to fund planning and engineering for restoration of 600 acres of the Ballona Creek wetlands in Marina Del Rey.
Helpfully to whatever restoration plans might or might not be on tap for the region (and central to the Sierra Club's opposition to the current plans to restore the Ballona wetlands), the report's appendices list all of the plant species found in the Ballona Valley, La Cienega, Ballona Lagoon, Santa Monica Mountains, and Inglewood and Centinela Creek regions.
· The Lost Wetlands of Los Angeles [KCET]
· Historical Ecology of the Ballona Creek Watershed [Southern California Coastal Water Research Project]
· Ballona Wetlands Getting Restoration, But Sierra Club Hates It [Curbed LA]