INSPEC26917

• Permit No: C1982057
• IBM Index Class Name: Inspection
• Doc Name: Inspection Report
• Inspection Date: 6/29/2006
• Media Type: D
• Archive: No

III. COMMENTS -COMPLIANCE
Below are comments on the inspection. The comments include discussion of observatioris made
during the inspection. Comments also describe any enforcement actions taken during the inspection
and the facts or evidence supporting the enforcement action.
• The steep lower segment is a trapezoidal riprapped channel that exceeds design dimensions,
and appears to be relatively stable. See Digital Image 2577.
006 Gulch Channel
GG to F (Upper end of channel upstream of Ridgeline Road down to 006-51 confluence)
This upper segment of the 006 Gulch drainage extends from a couple hundred yards upstream of the
Ridgeline Access Road down through Stock Pond T-5 and the fenced woody planting area below,
ending at the 006-S1 confluence, just west of the fenced planting area. Exhibit 20-5.1 depicts a concave
profile along the 2500'+ segment, with gradients in the 16%-17% range along the upper 1500',
decreasing to 2.8% at the S1 confluence. Figure 20-1.1 indicates "V" shaped vegetated channel 1.9'
deep, and 11.4 feet wide for channel segments in the 2% to 6% range. Design for channel segments in
the 7% to 18% range is trapezoid, with 2' bottom width, 0.8' depth, 6.8' top width, 6" D50 riprap.
At the very upper end of the watershed (upstream of the upper end of the constructed channel),
a gully has developed and water bars were breached along the steep reclaimed temporary route
from the Ridgeline light use road down to the aspen test plots. Regrading and repairs will be
required. Drainage from the Ridgeline light use road may have contributed to the
problem; diversion of runoff away from the upper end of the reclaimed temporary route
may be warranted. There are several other gullies on hill slopes on either side of the
upper channel segment above the Ridgeline Access Road that will also need to be
stabilized.
• Channel segment upstream of the Ridgeline Access Road appeared to conform with design
gradient; channel was trapezoid with dimensions exceeding design specifications. The channel
had been riprapped. There was minor scour in some locations with patches of underliner
exposed. It appears likely that the channel will stabilize and the scoured areas will fill in, but the
segment warrants monitoring.
The first +l- 250' segment of channel below the Ridgeline Access Road is at or slightly exceeds
the design gradient (measured at 20% gradej. The segment appears to have recently been
repaired (new riprap and fresh equipment tracks and ruts). Channel is trapezoid and appears to
exceed design dimensions, however the repair job appears to have not been fully completed.
The construction route adjacent to the channel needs to be scarified and stabilized to
eliminate ruts and prevent rill formation. Riprap needs to be graded out to eliminate
mounds and ridges along the channel sides that may prevent slope runoff from entering
the channel, and causing rills parallel to the channel. See Digital Image 2580.
• Channel appears to be within design limits down to Stock Pond T-5 inlet, and appears relatively
stable with some areas of minor scour that will need to be monitored, Construction road
parallel to the channel will need to be scarified, seeded and water-barred. There is a
gully extending from the road into the channel a short distance up from the pond inlet
that will need to be repaired.
• The low gradient channel segment downstream of the pond through the tree planting area down
to the S1 confluence is a large riprapped trapezoidal channel (rather than vegetated "V"
channel), but the reach appears to exceed design capacity and is stable.