Fuels Reduction and Vegetation Management

Geologic hazards related information and resources to assist in planning and implementation of fuels reduction and vegetation management projects such as the Statewide Fuels Reduction Environmental Protection Plan (EPP) and Vegetation Treatment Program (VTP).

CGS Forest and Watershed Geology Program (FWGP) – The FWGP provides technical information and advice about erosion, sedimentation, landslides, and other geologic hazards on California's forested lands and in watersheds where land-use decisions may affect public safety, water quality, and fish habitat.
- Email the Forest and Watershed Geology Program

Additional Resources from the California Geological Survey, Department of Conservation, California Natural Resources Agency, and CalEPA

Landslides

California Landslide Inventory and Deep-seated Landslide Susceptibility – The landslide inventory and map of deep-seated landslide susceptibility can give local planners, infrastructure owners, and the public a perspective on where landslides are most likely to be triggered by winter storms or by earthquakes in California
Reported California Landslides database – Interactive map built on data sent to CGS by government agencies, media, and citizen scientists.
California Geological Survey Note 50 – Factors Affecting Landslides in Forested Terrain.
California Geological Survey Landslides Page
Types of Landslides
California Geological Survey Watershed Maps and GIS Data
Guide to Determine Need for Input from a Licensed Geologist during THP Preparation – California Licensed Forester's Association Geologic Consultation Guidance

Roads and Watercourse Crossings

California Forestry Report No. 1 – Designing watercourse crossings for 100-year flood flow.
California Forestry Report No. 7 – Mitigating Potential Sediment Delivery from Post-Fire Salvage Logging.
APPENDIX C: California Board of Forestry and Fire Protection 2013 Road Rules and Technical Addendum No. 5 – Guidance on hydrologic disconnection, road drainage, minimization of diversion potential and high-risk crossings.
Handbook for Forest, Ranch & Rural Roads - A Guide For Planning, Designing, Constructing, Reconstructing, Upgrading, Maintaining and Closing Wildland Roads.

Naturally-Occurring Asbestos and other Mineral Hazards

Mineral Hazards of California
Naturally-Occurring Asbestos (NOA):

Other CGS Programs, DOC Divisions, and VMP chapters with information relevant to geologic aspects of Fuels Reduction project planning

Mineral Hazards of California – The CGS provides maps, geologic information and advice, and monitors activity on minerals-related environmental and public health issues such as asbestos, mercury and radon.
California Geologic Energy Management Division Well Finder – Well Finder is an interactive map viewer that provides locations of oil, gas, and geothermal facilities in California.
Division of Mine Reclamation Abandoned Mine Lands Unit – Information about the presence and hazards related to abandoned mine features.
California Vegetation Management Plan Chapter 3.4 Air Quality – Potential mitigations to reduce impacts to air quality from implementation of Fuels Reduction projects.
California Vegetation Management Plan Chapter 3.7 Geology, Soils, and Mineral Resources – Potential mitigations to reduce impacts to geology, soils, and mineral resources from implementation of Fuels Reduction projects.

Definitions from California Forest Practice Rules pertaining to geologically sensitive landscape features

Saturated Soil Conditions means that soil and/or surface material pore spaces are filled with water to such an extent that runoff is likely to occur. Indicators of saturated soil conditions may include, but are not limited to:
1. areas of ponded water,
2. pumping of fines from the soil or road surfacing material during Timber Operations,
3. loss of bearing strength resulting in the deflection of soil or road surfaces under a load, such as the creation of wheel ruts,
4. spinning or churning of wheels or tracks that produces a wet slurry, or
5. inadequate traction without blading wet soil or surfacing materials.
Slide Areas are areas indicated by the following characteristics:
1. Shallow-seated Landslide. An area where surface material (unconsolidated rock colluvium, and soil) has moved downslope along a relatively steep, shallow failure surface. The failure surface is generally greater than 65% in steepness and less than 5 feet in depth. It is usually characterized by:
  1. a scarp at the top;
  2. a concave scar below the scarp, where surface material has been removed; and sometimes
  3. a convex area at the bottom where slide material is deposited. Vegetation is usually disturbed (tilted trees), anomalous (younger, evenaged stand), or absent (bare soil). Minor bank slumps are excluded from this definition.
2. Deep-seated Landslide. An area where landslide material has moved downslope either as relatively cohesive mass (rotational slides and translational block slides) or as an irregular, hummocky mass (earthflow). The failure surface is generally deeper than five feet and is usually well-exposed at the head scarp. Complex failures with rotational movement at the head and translational movement or earthflows downslope are common. Vegetation on rotational and transitional slides is relatively undisturbed, although trees and shrubs may be pistol-butted or tilted. Deep-seated landslides may have intermediate tension cracks, scarps, and shallow slides superimposed throughout the slide mass. Deep-seated landslide risk is usually associated with cohesive soils.
Unstable Areas are characterized by slide areas or unstable soils or by some or all of the following: hummocky topography consisting of rolling bumpy ground, frequent benches, and depressions; short irregular surface drainages begin and end on the slope; tension cracks and head wall scarps indicating slumping are visible; slopes are irregular and may be slightly concave in upper half and convex in lower half as a result of previous slope failure; there may be evidence of impaired ground water movement resulting in local zones of saturation within the soil mass which is indicated at the surface by sag ponds with standing water, springs, or patches of wet ground. Some or all of the following may be present: hydrophytic (wet site) vegetation prevalent; leaning, jackstrawed or split trees are common; pistol-butted trees with excessive sweep may occur in areas of hummocky topography (note: leaning and pistol butted trees should be used as indicators of slope failure only in the presence of other indicators).
Unstable Soils may be indicated by the following characteristics:
1. Unconsolidated, non-cohesive soils (coarser textured than Loam, as defined in Appendix I.A.1a of Board of Forestry Technical Rule Addendum No. 1, dated December 15, 1981) and colluvial debris including sands and gravels, rock fragments, or weathered granitics. Such soils are usually associated with a risk of shallow-seated landslides on slopes of 65% or more, having non-cohesive soils less than 5 ft. deep in an area where precipitation exceeds 4 in. in 24 hours in a 5-year recurrence interval.
2. Soils that increase and decrease in volume as moisture content changes. During dry weather, these materials become hard and rock-like exhibiting a network of polygonal shrinkage cracks and a blocky structure resulting from desiccation. Some cracks may be greater than 5 feet in depth. These materials when wet are very sticky, dingy, shiny, and easily molded.
Road Maintenance means activities used to maintain and repair roads involving minor manipulation of the road prism to produce a stable operating surface and to ensure road drainage facilities, structures, cutbanks and fillslopes are kept in a condition to protect the road, minimize erosion, and to prevent sediment discharge into a Watercourse or lake. Examples of road maintenance include shaping and/or rocking a road surface; installation and maintenance of rolling and critical dips; restoring functional capacity of inboard ditches, cross drains, or culverts; and repairing water bars.
Road Prism means all parts of a road including cut banks, ditches, road surfaces, road shoulders, and road fills.
Stable Operating Surface means a road or Landing surface that can support vehicular traffic and that routes water off of the road surface or into drainage facilities without concentrating flow in ruts (tire tracks), pumping of the road bed, or ponding flow in depressions. A stable operating surface shall include a structurally sound road base appropriate for the intended use. The number, placement, and design of drainage facilities or drainage structures on a stable operating surface prevents the transport of fine-grained materials from the road or Landing surface into Watercourses in quantities deleterious to the beneficial uses of water.

Web page by:
California Geological Survey - Forest and Watershed Geology Program