Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): Jason S. Woodward; Matthew R. House; David W. Lamphear
    Date: 2017
    Source: Gen. Tech. Rep. PSW-GTR-258. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station: 149-161
    Publication Series: General Technical Report (GTR)
    Station: Pacific Southwest Research Station
    PDF: Download Publication  (591.0 KB)


    Shallow streamside landslides are a principle source of sediment on managed timberlands in northern California. Using an adaptive management process, LiDAR, and a detailed field-based landslide inventory, Green Diamond Resource Company (GDRCo) has redefined the interim preventative landslide tree-retention buffers it applies to steep streamside slopes along fish bearing (Class I) and non-fish bearing (Class II) watercourses. The application of these buffers are dependent on slope gradients and when applied, enhance and in some cases, expand upon the customary riparian buffers associated with these watercourse types in our California Timber Harvesting Plans (THP). They are designed to significantly reduce the amount of management related sediment delivery associated with landsliding when compared to historical management practices.

    Initially, the steep slope prescriptions were derived from a pilot field inventory of streamside landslides during the developmental stages of an Aquatic Habitat Conservation Plan (AHCP). The Steep Slope Delineation study was a long term research project associated with the AHCP monitoring program with an objective of redefining the initial prescriptions based on a comprehensive field-based landslide inventory. The first phase of the steep slope project was completed in 2011, and in 2015 we completed the final phase.

    The final results of the Steep Slope Delineation project covered roughly 145,690 ha (360,000 ac) of privately owned timberlands in California. The work included a review of aerial photographs, detailed field survey of slopes adjacent to 357, 0.8 km (half-mile) long, watercourse segments, and analysis of the resulting data. These data, characterizing more than 2,000 landslides, are used to develop new maximum buffer widths and new slope gradient buffer triggers which are exclusive to the four geographic areas within the ownership. While the majority of the buffer widths decreased, nearly one third increased in width. As for the slope triggers, slightly more than half of the slope gradients decreased, nearly half had no change, and a few increased. The revised steep slope prescriptions were submitted to federal agencies in December of 2014 and were successfully incorporated into the AHCP in January of 2015.

    Publication Notes

    • You may send email to to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.


    Woodward, Jason S.; House, Matthew R.; Lamphear, David W. 2017. Development of preventative streamside landslide buffers on managed timberlands. In: Standiford, Richard B.; Valachovic, Yana, tech cords. Coast redwood science symposium—2016: Past successes and future direction. Proceedings of a workshop. Gen. Tech. Rep. PSW-GTR-258. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station: 149-161.

    Related Search

    XML: View XML
Show More
Show Fewer
Jump to Top of Page