_PERMIT FILE - M2000052

• Permit No: M2000052
• IBM Index Class Name: Permit File
• Doc Name: MAPS & EXHIBITS
• Media Type: D
• Archive: No

U.S. DEPARTMENT OF AGRICULTURE PAGE 2 OF 3
NATURAL RESOURCES CONSERVATION SERVICE 01/18/00
•
WATER FEATURES
Endnote -- WATER FEATURES
This report gives estimates of various soil water features. The estimates are used in land use planning that involves
engineering considerations.
Hydrologic soil groups are used to estimate runoff from precipitation. Soils not protected by vegetation are
assigned to one of four groups. They are grouped according to the infiltration of water when the soils are thoroughly
wet and receive precipitation from long-duration storms. The four hydrologic soil groups are:
Group " A". Soils having a high infiltration rate flow
runoff potential) when thoroughly wet. These consist mainly
of deep, well drained to excessively drained sands or
gravelly sands. These soils have a high rate of water
transmission.
Group "B". Soils having a moderate infiltration rate when
thoroughly wet. These consist chiefly of moderately deep or
deep, moderately well drained or well drained soils that
have moderately fine texture to moderately coarse texture.
These soils have a moderate rate of water transmission.
• Group "C". Soils having a slow infiltration rate when
thoroughly wet. These consist chiefly of soils having a
layer that impedes the downward movement of water or soils
of moderately fine texture or fine texture. These soils
have a slow rate of water transmission.
Group "D". Soils having a very slow infiltration rate (high
runoff potential) when thoroughly wet. These consist
chiefly of clays that have a high shrink-swell potential,
soils that have a permanent high water table, soils that
have a claypan or clay layer at or near the surface, and
soils that are shallow over nearly impervious material.
These soils have a very slow rate of water transmission.
If a soil is assigned to two hydrologic groups in this report, the first letter is for drained areas and the second
is for undrained areas. Flooding, the temporary inundation of an area, is caused by overflowing streams, by runoff from
adjacent slopes, or by tides. Water standing for short periods after rainfall or snowmelt is not considered
flooding, nor is water in swamps and marshes. This report gives the frequency and duration of flooding and
the time of year when flooding is most likely. Frequency, duration, and probable dates of occurrence are estimated.
-- Frequency is expressed as "None", "Rare", "Occasional", and "Crequcnt". "None" means that flooding is not probable;
"Rare" that it is unlikely but possible under unusual weather conditions; "Occasional" that it occurs, on the
average, once or less in 2 years; and "Frequent" that it occurs, an the average, more than once in 2 years.
Duration is expressed as "Very brief" if less than 2 days, "Brief" if 2 to T days, "Long" if T to 30 days, and -Very
0d" if more than 30 days. The inEorma Cion is based on evidence in the soil profile, namely Chin strata of gravel,
-. , silt, or clay deposited by floodwater; irregular decrease in organic matter content with increasing depth;
and absence of distinctive horizons that form in soils that are not subject to flooding. Also considered are local
information about the extent and levels of flooding and the relation of each soil on the landscape to hister:c Elocds.