Southern California, in particular the greater Santa Monica Bay area, has long been renowned for its year-round pleasant climate and recreational beaches. As far back as the end of the nineteenth century, residents and visitors were already discovering the pleasures of beach-going, including natural and man-made amusements, camping, fishing, picnicking, etc.
After World War II, the population of greater Los Angeles boomed, fueled in part by the entertainment industry and--for the Santa Monica area especially--the aerospace industry. The promise of employment coupled with the sunny climate brought new home seekers to the west coast, where thousands of new homes and businesses were built to accommodate the burgeoning population. By the mid-1940s, the impact to lands along the coast led activist citizens and lawmakers to discuss and formulate a plan to preserve California's most valuable lands for future generations.
According to T.H. Abell's A Shoreline Master Plan for Los Angeles (1946, published online in 2007 by the Journal of the American Institute of Planners), the ocean shoreline of Los Angeles County consisted of 65.4 miles, not including the Los Angeles Harbor frontage. 11.66 of those miles belonged to the City of Los Angeles, and 10.2 miles of the city were in Santa Monica Bay--part being north of the City of Santa Monica and part being on the south side.
Since the late 1800s, residents and tourists had enjoyed the wide sandy beaches of the Santa Monica Bay, including the many piers and amusement zones created by Abbott Kinney and other enterprising developers. Gradually private development along the beaches--hotels, restaurants, homes, etc.--closed much of the beach to public access and use. In addition, off-shore structures and breakwaters had affected wave and current action, causing erosion to the point where shoreside buildings were undermined or destroyed. And though Santa Monica once boasted a thriving fishing industry, continuous development and increased population of the Los Angeles area contributed to a drastic decline in water quality as trash and sewage run-off ended up in the Santa Monica Bay. Though clean-water legislation and restoration projects improved the quality of the Bay's waters over the years, the Shoreline Master Plan for Los Angeles (1947) was one of the first formal attempts to address the issues confronting the area's shores and beaches.
Back in the 1940s, so much of the beach properties were privately owned that the public was being relegated to smaller and smaller strips of it and would eventually be excluded from the beaches altogether. To prevent this from happening, Los Angeles City, Los Angeles County, and the State of California began acquiring parcels of beach frontage for public use. The three agencies worked together to develop shoreline master plans which became the basis for future development.
The proposed plan was to transfer City and County beaches to State ownership, so that the State could then purchase adjacent frontage of equal value--and eventually the entire beach frontage would be State owned. The State would then lease the beaches to City, County, or other local governmental bodies to develop and administer.
Some of the features of the Master Plan included:
Continuous sandy beach, 250 feet wide
Continuous boardwalk, connecting all parts
Pedestrian underpasses to eliminate surface crossing of Scenic Drive
Public bathhouses and concessions at frequent intervals along beach
Picnic areas and play areas back of the boardwalk
Fishing piers for public use
Trailer and cabin parks for visitors' use
Bird sanctuary in marsh area south of Ballona Creek
The survey that was conducted before the details of the Plan were created provided data that was essential in calculating the needs of the existing and anticipated population. They included statistics such as "75 sq. ft. sand area per person", "3.3 persons per car in parking lots", and "50 per cent of visitors in private automobiles, the rest using mass transit facilities".
More detailed information on both the Los Angeles County Master Shoreline Plan and the Santa Monica Bay Shoreline Development Plans is available here:
T. H. Abell (1946) "A Shoreline Master Plan for Los Angeles", Journal of the American Institute of Planners,
12:3, 25-27, DOI: 10.1080/01944364608978593
Johnson, A. (2010). "SANTA MONICA BAY SHORELINE DEVELOPMENT PLANS. Coastal Engineering Proceedings", 1(1), 30. doi:10.9753/icce.v1.30