_PERMIT FILE - C1981008A ‎(13)‎

• Permit No: C1981008A
• IBM Index Class Name: PERMIT FILE
• Doc Name: Sedimentation Pond 004
• Section_Exhibit Name: Tab 13 Attachment D
• Media Type: D
• Archive: Yes

TABLE 6
Design Storage Capacity Summary
Sediment Pond 004
Stage Capacity
Elevation (Feet) (Ac-ft) Description
5658. 0.0 0.00 Bottom of Pond
5662.0 4.0 0. 11 Elevation of Principal
Spillway and 100%
Sediment Storage
5665.07 7.07 0.29 10-year, 24-hour Peak
Stage
5665.89 7.89 0.34 25-year, 24-hour Peak
Stage
5666.0 8.0 0.35 Elevation of Emergency
Spillway
5667.42 9.42 0.48 100-year, 24-hour Peak
Stage
5668.0 10.0 0.53 Top of Embankment
Peabody does not anticipate any pit pumpage or other inflow to the pond
at this time.
SPILLWAY
Sediment Pond 004 provides for a combination of principal-emergency
spillway to safely discharge the runoff from a 25-year, 24-hour storm.
The principal spillway inlet will also be used as the nonclogging
dewatering device and is located at an elevation higher than the maximum
sediment storage volume. The principal spillway inlet is located in a
position on the embankment so as to prevent short-circuiting diameter as
much as possible. The stage-discharge relationship of the emergency
spillway inlet was calculated using SEDIMOT II , while the
stage-discharge relationship of the principal spillway inlet was
calculated using the orifice flow equation below:
9