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Soil Survey Manual - Table 3-2

Water-state classes

Class Criteriaa
Dry (D) >1500 kPa suction
     Very Dry (DV) <(0.35 x 1500 kPa retention)
     Moderately Dry (DM) 0.35 to 0.8 x 1500 kPa retention
     Slightly Dry (DS) 0.8 to 1.0 x 1500 kPa retention
Moist (M) <1500 kPa to >1 or 1/2 kPab
     Slightly Moist (MS) 1500 kPa suction to MWRc
     Moderately Moist (MM) MWR to UWRc
     Very Moist (MV) UWR to 1 or 1/2 kPab suction
Wet <1 kPa or <1/2 kPab
     Nonsatiated (WN) No free water
     Satiated (WA) Free water present

a. Criteria use both suction and gravimetric water contents as defined by suction.
b. 1/2 kPa only if coarse soil material (see text).
c. UWR is the abbreviation for upper water retention, which is the laboratory water retention at 5 kPa for coarse soil material and 10 kPa for other (see text). MWR is the midpoint water retention. It is halfway between the upper water retention and the retention at 1500 kPa.