Soils of the - Agriculture and Agri-Food Canada

CARVOLTH SOILS . (CV)
Location and Extent : Carvolth soils occur along various streams on the uplands, mainly in Langley an d
Surrey Municipalities . There are a total of 450 ha of pure map units and an additional 30 ha of Carvolth-Westlan g
soil complex .
Topography and Elevation : Carvolth soils are level to undulating and usually depressional in relation t o
surrounding soils . Slope gradients are less than 5 percent and elevations mostly range between 10 and 30 m
above sea level .
Parent Material and Texture : Carvolth soils have developed from moderately fine textured, stone-free ,
floodplain deposits of local streams . The deposits consist mainly of materials originally eroded from moderatel y
fine and fine-textured marine and glaciomarine upstream sediments . Surface textures vary from silty clay loa m
to silt loam while subsurface and subsoil textures are usually silty clay loam or silty clay. A few thin, sandy lense s
and strata may also occur. Fine-textured marine deposits usually occur at depth .
Soil Moisture Characteristics : Carvolth soils are mostly poorly or very poorly drained although a few ,
imperfectly drained areas along Campbell River are also included . The soils are slowly pervious and wate r
holding capacity is high . Surface runoff is moderate to slow and seepage from higher adjacent soils tends to
accumulate . Flooding during heavy rains is common in most areas .
General Soil Description : Carvolth soils have a friable to firm, cultivated, silty surface layer about 15 c m
thick which is dark grayish brown in colour. It is underlain by grayish-brown or brownish-gray, clayey material, at
least 70 cm thick, that contains common, reddish-brown or yellowish-red mottles and breaks in large, hard ,
angular clods . At depth, below 1 m or more, clayey, olive-gray to dark gray, massive, unweathered marine o r
glaciomarine deposits are encountered . Soil reaction varies from medium acid in the upper layers to slightl y
acid in the subsoil (1 :1 H 2O) . Soil classification is Rego Humic G/eysol.
Commonly Associated Soils : Berry, Cloverdale, Milner and Westlang soils are often closely associate d
with Carvolth soils . They all differ from Carvolth soils by having developed from marine deposits . Additionally,
Cloverdale and Berry soils have well-defined clay accumulation subsurface layers . Also, Berry and Milner soil s
respectively are imperfectly and moderately well drained .
Vegetation : Some areas have been cleared for agricultural use, mainly for pasture or forage . The remaining ,
uncleared areas support willow, vine maple, black cottonwood and other mainly deciduous species tolerant o f
high watertables . The undergrowth includes sedges, reeds and grasses . Rooting is restricted mainly to th e
upper 50 cm by high watertables and dense, clayey subsoils .
General Land Use Comments : (1) Agriculturally, Carvolth soils are presently mainly restricted to forag e
and pasture use by poor drainage and potential for flooding . Water control (both flooding and groundwater )
improves the range of crops possible but, in most cases, is relatively costly . (2) Urban or similar construction i s
not suited because of high watertables, flooding potential and variable soil bearing strengths . Septic tan k
operation is poor because of high watertables and very slow subsoil permeability .
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