National Geographic : 1969 Oct
"Geologists like myself also inspect and map the deeper strata. And I mean 'inspect.' We sink borings and even go down into some of them. Air photos often show things you can't see on the ground, and we use them regularly." With better knowledge of the environment have come sound building laws and fire regu lations-probably the best in the Nation, says Dr. Stout. In 1952 Los Angeles passed a city ordinance prohibiting construction on dan gerously steep slopes, on uncompacted fill, or on known unstable areas. Surrounding coun ties have since passed similar codes. The city's effective "green hills" statute, requiring scien tific landscaping and dry-season irrigation of the ground cover, went on the books in 1961. "Last winter proved the worth of the city regulations," said Martin Stout. "Few struc 570 tures built to their grading specifications sustained more than minor damage." Among the regulations specifically aimed at preventing the classic fire-flood sequence is a ban on smoking (even in automobiles) in critical foothill areas during the dry season. A $10,000,000 Repair Job In the southland, virtually all major water sheds are in four national forests. The agency charged with caring for these natural flood defenses is the U. S. Forest Service. Actually, "forest" is a misnomer for the scrub-covered foothills, although timber clothes the high country farther east. Originally established solely to preserve the delicate watershed, the forests now play host to increasing millions of vacationists; rangers counted 19,000,000 in dividual visits in 1968.