REV88252

• Permit No: M1976009HR
• IBM Index Class Name: Revision
• Doc Date: 12/2/1996
• Doc Name: EXHIBIT I SOILS INFO
• Type & Sequence: AM3
• Media Type: D
• Archive: No

character of the drainages as a whole. In some cases it was felt that too much vegetation was
growing in the drainage to be considered a real channel or the vegetation was not distinctive
enough from normal valley bottom and side slope vegetation, considering the variations
within those vegetation units. In other cases, some sites that were initially considered
questionable were included in the Waters of the United States category.
Once all sites were located, they were measured to determine the amount of land
included in the Waters of the United States category throughout the site. The amount of land
in the Waters of the United States category would determine what action was appropriate
with respect to the regulatory structure.
Measuring such units is no simple matter as the boundaries between adjacent units are
often broad and although the edges may more or less parallel the channel, the actu;d
boundary can meander irregularly producing variable widths. The extent of such an area up
and down a drainageway is more easily defined than the width. Boundaries between units
along the drainageway are often defined by topographic changes in stream gradient or
changes in rock types or the configuration of the valley bottom. But the edges of such units
where they meet side slope vegetation are often vague, especially where the vegetation on the
side slopes differ little from the vegetation along the channel (e.g. east and west faring
slopes along a northward trending drainage).
Furthermore, with highly intermittent streams many species found in the bottom of
the valleys can be similar to those that are found on the side slopes above the draicage,
irrespective of slope aspect or drainageway orientation. In a sense, such drainagew;rys do not
necessarily form a separate vegetation unit but are the transition zone between adjacent slope
vegetation units.
The vegetation in such situations can be a blend of the vegetation found on adjacent
slopes plus a few other species that prefer the somewhat more moist conditions of the
drainageway. In those cases, deciding what is Waters of the United States and what is not
becomes a value judgement based on how different the vegetation is from side slope
vegetation and how many distinctive species are found in those areas but not gener;rlly found
on the side slopes. Once again, this forms a spectrum from highly distinctive (e.g. cattails
and willows in the drainageway with cactus and Juniper on adjacent slopes) to a di:;tinction
that may be defined by slightly larger Rocky Mountain Maples or slightly more Poison Ivy in
the drainageway than is found on the side slopes.
In marginal situations, the nature of the drairtage channel and the soils were used to
decide. If the drainage channel was present, but had vegetation (anything from grass to small
trees) growing in the path the site was rejected. But if the drainageway was as described and
the soils appeared to be wet throughout most of the year then it was included as Waters of
the United States .Water seeps and small springs, especially if present in August and
September, were always included as Waters of the United States sites.
Waters of the US Study Menzer Quarry Page 2