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Early Soil Conservation on the Palos Verdes Peninsula

By Monique Sugimoto and Dennis Piotrowski

LOST! TONS OF FERTILE CALIFORNIA SOIL BY EROSION.  This is the title of a 1935 publication by the Soil Conservation Service (SCS) that described the critical state of California’s farmland.  After successive years of drought in the early years of the Great Depression and the worst dust storms ever, the country’s natural resources were thrust into the national consciousness.  

Recognizing that “wastage of soil and moisture resources” due to soil erosion was “a menace to the national welfare,” the federal government established the SCS in 1935 to prevent soil erosion and preserve our soil and water resources.  

The SCS quickly established demonstration projects on privately owned land to teach farmers, landowners and soil conservation associations methods to control erosion and to illustrate the benefits of conservation.  

The first demonstration project in Los Angeles County was on the Palos Verdes Peninsula.  The project covered the farm and ranch land on the western side of the Peninsula and areas from Crest Road to Palos Verdes Drive North.  

According to a 1934 soil erosion reconnaissance survey of California, just under half of the thirty million acres of farmable land in California were either severely or moderately eroded.  Similarly, about half of the land surveyed on the Peninsula was affected by soil erosion and required treatment. 

The Peninsula suffered from “sheet erosion,” where soil is moved downslope in sheets rather than in channels.  Steep land and cultivation methods caused this.  Another form of erosion characteristic of the area was “gully erosion” where water runoff cut deep ravines into the hillsides.  Gully erosion was aggravated by road construction that concentrated water runoff.  

Civilian Conservation Corps (CCC) workers housed at nearby Fort MacArthur provided labor for the project.  The SCS placed contour ditches at the tops of cultivated lands and terraced the lower areas to curtail areas of sheet erosion.  Small dams and diversion ditches were constructed to control the gullies.  Gullies were stabilized with reinforced concrete, rock masonry, earth fills, and loose rock. 

Once erosion control measures were in place, native and non-native trees, shrubs, and grasses were planted to further stabilize the land.  Pasture lands, terrace outlets and ditches were seeded with a variety of plants including Australian Saltbush, Burr Clover, Common Oat, Brown Mustard, California Buckwheat, and Sudangrass.  

A sample of the plants used in the gullies include Kangaroo Thorn, Silk tree, Bottlebrush, Gum, Locust, Sycamore, Elm, Eucalyptus, Lemonade Berry and Blue Elderberry.  The Southern California walnut, a California native and now rare, was also used. 

During the 1935 -1936 planting season alone -- which was reduced to only 60 days because of a short rainy season -- ninety six thousand trees were planted.  With little rainfall during the summer season, a crew of 10 men provided irrigation to the newly planted areas. 

To control damage to new plantings and the engineering structures by gophers, squirrels, rabbits and wood rats, areas were baited and trapped before and during the planting and construction of the soil control measures.  Over 10,000 acres of land were treated; the SCS won its battle with the rodents. 

The results of the SCS measures were seen immediately.  Terraces placed on cultivated lands near Point Vicente Lighthouse stopped mudslides that washed out Palos Verdes Drive when it rained.  

SCS activities also included handling fires.  According to the 1936 annual report, the SCS supervised fire control on over 10,000 acres of land and handled five fires.  The president of the Palos Verdes Homes Association reportedly discussed plans for a fire trail and plantings in the area from the Golf Course extending to the Douglas Cut.

In 1936, the SCS started to cut back on demonstration projects.  Though there was still work to do on the Peninsula, the regional director determined sufficient demonstration work had been done and recommended closing the project.   By the summer of 1937, the SCS CCC camp at Fort MacArthur was relocated to Cucamonga to take care of work there, and the Palos Verdes project was put on maintenance.  

From October 1935 to April 1937, the SCS created 45 miles of terraces and 209 small masonry or concrete dams to stabilize gullies for the Palos Verdes demonstration project.  Over 349 acres of the most highly erodible lands were planted with trees and tens of thousands of linear feet of diversion ditches were created and hillsides graded.  

The work of the SCS in the 1930s were the beginnings of a program to “keep the rain drop where it falls” and concerted efforts to preserve and protect the valuable soil and moisture resources of the Peninsula. 

Monique Sugimoto and Dennis Piotrowski are librarians in the Adult Services department of the Palos Verdes Library District.