Rancho Seco Erosion

About 45 miles north of the Antelope Valley, located a few miles east of US Highway 395 is the small desert town of Rancho Seco. Also nearby is Honda proving grounds for their passenger vehicles. During the past 15 years, the town and the Honda site have been periodically impacted by sandstorms. Some of this sand has emanated from several thousand acres of abandoned land farmed prior to the 1980’s. Some of this sand may also be transported from a large desert wash called Jawbone. During heavy rains and summer thunderstorms this wash can fill with water, but most of the time it is dry.

Rancho Seco and the Honda complex are located downwind of these two potential source areas. During recent surveys, large buildups of sand were observed throughout the town and in parts of the Honda land. Building structures and vegetation caused the dunes to form, trapping sand that had moved over great distances from the south through northwest.

Following these site surveys, a two-part mitigation plan has been prepared. The first phase consists of short-term remedial stop-gap emergency measures designed to mitigate the sand migration into the yards and homes of Rancho Seco. The second phase focuses on identification of the sources of the migrating sand and methods to mitigate these identified sources. The containment, stabilization and prevention strategies in these plans rely on the use of Cox sandcatchers to monitor sand flux rates), wind fences to capture saltating sand and wood chips placed near and in between wind fences in order to stabilize sand accumulations prior to eventual removal/burying of the sand. In some areas, native vegetation seedlings and/or direct seeding may also be utilized. The Honda complex has undergone some limited revegetation from seeding of natives. We will revegetate those areas that will remain permanently undisturbed and that are conducive to seedlings and/or seeding. Wind fence design consideration will include porosity/blockage, number of fence rows, fence heights, and locations upwind of the west and north town boundaries. A porosity in the range of 60-70% for these 4-feet high fences is projected to be the most cost-effective for this application.