PERMFILE112403

• Permit No: C1980001
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Doc Name: Rationale for Sedimont II Input Parameters
• Section_Exhibit Name: 4.6 APPENDIX 4.6-M‎(a)‎
• Media Type: D
• Archive: No

• RATIONALE FOR SEDIMOT II INPUT PARAMETERS
I. In preparing the Sedimot II check dam outputs the following parameter
values were used to obtain output values listed in the worksheet summaries.
(A). Storm Input
(1). Storm Type - SCS's Type 2 which is the Sedimot II default
value.
(2). Rainfall depth and duration - Based on l0 year (1.80")
and 100 year (2.62") 24 hour precipitation event. These
rainfall depths and duration values were obtained from
section 2.5-4 of the approved Edna Mine Permit
Application.
(3). Time Increments -One-tenth (1/10) of an hour was
considered an acceptable value of time for these size
watersheds by the originator of Sedimot lI, (University of
Kentucky).
(B). W atershed Data
Watershed data - Watersheds were dissected using the
map illustration shown on Exhibit 4.6-M2.
(C). B etween Structure Rautin¢ Parameters - Between structure
routing parameters were derived from calculations
• obtained in worksheet I in Appendix 4.6-M(a).
(D). Hy draulic Input Values For Subwatersheds -The area for water-
sheds was planimetered for acres and the curve numbers
derived from values listed in Table 2.20, T~ Applied
Iiydroloev i~ Sedimentolo¢v E4.C Disturbed fig,
Barfield, Warner and Haan, Oklahoma Technical Press 1981.
(1). Curve No. 70 - Represents forest land with good cover.
(2). Curve No. 74 -Represents range land in good condition.
(Topsoil)
(3). Curve No. 79 - Represents range land in poor condition.
(Spoils)
(4). Time of Concentration - Derived from calculation
on worksheet I & II contained in Appendix 4.6-M(a).
(5). Travel Time - Derived from calculation on
worksheet I & II of Appendix 4.6-M(a).
(6). K Value -Derived from calculation on worksheet I
& U of Appendix 4.6-M(a).
(7). X Value -Derived from calculation on worksheet I &
TI of Appendix 4.6-M(a)
(E). Unit Hydrograph - Based on an agricultural condition.
•