APPCOR10528

• Permit No: C1994082
• IBM Index Class Name: Application Correspondence
• Doc Date: 6/19/1995
• Doc Name: INSERTION INSTRUCTIONS PERMIT APPLICATION C-94-082 YOAST MINE
• Media Type: D
• Archive: No

Erodible 1.70
Vegetated 2.26
*For both columns, ohe foot of freeboard is included
for all three diversion ditch designs.
The results show that a V-ditch 2.5-foot deep will
certainly carry the flows for both conditions.
Depth of Flow*
~~
Too Width of Ditch*
17.00
22.58
Diversion Ditch No. 2
No changes were
SEDCAD+ output
results:
Erodible
Vegetated
Therefore, the
deep with 3:1
generated.
necessary for
calculations
depth of Flow
1.61
2.28
results show
side slopes
the existing design. The
provided the following
Too Width of Ditch
9.67
13.70
that a V-ditch 2.5-foot
will handle the flows
Diversion Ditch No. 3
This ditch required that a new design be considered
because of the peak discharge generated by the storm
event. Instead of the original V-ditch design, the
revised trapezoidal design with a bottom width of 12
feet and 3:1 side slopes should provide adequate
carrying capacity. The SEDCAD+ output calculations are
as follows:
Depth of Flow* Ton Width of Ditch*
Erodible 1.24 19.44
Vegetated 1.62 21.70
This shows that a 2.0-foot deep trapezoidal channel
with a 12-foot wide bottom will be of sufficient size.
In closing, once all three diversion ditches are
constructed, they will be closely monitored for any
potential erosion. The SEDCAD+ results show conditions
should be stable. Additional appropriate sediment
control measures for these diversions are discussed on
Page 3 of Tab 13. Seneca believes the revised designs
should remain stable until vegetation is established.
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