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layer is a pale-brown loam about 6 inches thick, underlain by a brown heavy loam about
10 inches thick. The underlying substratum is generally a hard shattered shale or
fine-grained sandstone parent rock. Outcrops cover approximately 2 to 4 percent of the area.

Surface runoff is medium to rapid, and sheet and rill erosion are moderate. These soils
have a high EI-IR. Soil permeability is moderate, and the soils are generally well drained.
Limitations for road development are steep slopes and hard sandstone and shale at depths
of 20 to 40 inches. These soils are rated as fair for engineering purposes according to the
AASHO engineering classification system and have moderate allowable soil pressure ratings

(USDA, 1969 and 1970), with a moderate shrink-swell potential (Table 3).

Saugus series: These soils are found in the northwestern and western portion of the project
property and consist of loam. These soils are found on slopes of 30 to 50 percent range and
in depth from approximately 36 to 60 inches. A typical soil profile consists of about
15 inches of grayish-brown loam at the surface, underlain by a poorly developed loam

subsoil and weakly consolidated gravelly sand and shale parent rock. Surface runoff is rapid,
and sheet and gully erosion can be high. The erosion hazard of Saugus soils is rated as
high. Permeability is moderate, and the soil is generally well drained. There are not any
adverse features listed for road location in this material; it is rated as generally good for
engineering purposes by AASHO, and has moderate allowable soil pressure ratings (USDA,
1970). These soils also have a low shrink-swell potential (Table 3).

Castaic and Saugus Series: A small area in the western portion of the project property
consists of intermixed Castaic and Saugus soils. These soils are found on slopes of 30 to
65 percent and consist of silty, clayey loam. Saugus soils are similar to that described in the
preceding paragraph. Castaic soils range in depth from approximately 18 to 36 inches. A
typical profile consists of about 9 inches of silty clay loam, approximately 15 inches of

yellowish-brown silty clay loam and an underlying parent rock of soft shale and sandstone.
Runoff is rapid, and sheet and gully erosion are very high. Topography in this soil type is
characterized by steep, narrow, incised valleys. During heavy storm events, runoff is heavily
laden with silt. The erosion hazard of Castaic soils is very high. This material has slow to

moderately slow permeability ratings and is generally well drained. Limitations for siting
roads in this material are steep slopes and weathered shale at depths of 20 to 30 inches.
This material is rated by AASHO as poor for engineering purposes and has a moderate
allowable soil pressure rating (USDA, 1970), with a moderate shrink-swell potential
(Table 3).

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