2025-05-05_PERMIT FILE - C1981010 ‎(23)‎

• Permit No: C1981010
• IBM Index Class Name: Permit File
• Doc Date: 5/5/2025
• Doc Name: pages 4-172 to 4-222z
• Section_Exhibit Name: 4.8 Hydrologic Impacts
• Media Type: D
• Archive: No

Table 4.8-3. Diversion ditch sizing.

Peak Flow b D Slope v
Diversion (cfs)(1) (ft)(2) (ft)(3) (ft/ft) fps(4)

Far East Buzzard No. 1 0.7 0 0.44 0.02 1.5

East Pyeatt No. 1 51.0 17.0 0.45 0.05 6.3

South No. 3 0.1 1.1 0.05 0.07 1.7
South No. 4 8.2 1.0 0.66 0.04 5.3

No Name No. 1* N/A 0 0.25 0.03 N/A
No Name No. 2* N/A 0 0.25 0.02 N/A

West Pyeatt No. 1 72.0 12 0.43 0.156 13.04

West Flume No. 2 14.9 0 1.17 (5) 0.04 3.5

Horse 1.0 0 0.47 0.096 2.2

East Middle Flume A98-3** -- -- -- -- .08

East Flume*** -- -- -- -- --

Deal #2 Pond Diversion 9.41 12 1.24 0.07 5.86

Grouse Diversion to E. Pyeatt 33.36 15 0.49 0.028 4.22

No Name East 4.70 5.0 0.25 0.036 3.46
No Name West 10.86 5.0 0.40 0.036 4.63

Johnson Stockpile West 5.17 0.0 0.68 0.026 3.8
Johnson Stockpile East 3.25 0.0 0.64 0.014 2.7

N Pit***** 74.90 20 0.61 0.020 6.1

Coyote West 6.90 5.0 0.26 0.03 3.73

East C Pit 0.39 0 0.26 0.057 2.83

J Pit Diversion 0.82 0 0.42 0.022 2.37

L Pit Diversion 0.89 0 0.38 0.043 3.14

* Diversion carrying runoff from undisturbed areas.
**Diversion constructed using typical ditch design, (APP Q XVII).
***Diversion not constructed at this time.
****Deal Diversion model within Deal Pond model, (APP Q XXXVI).
*****Designed for a 25 year, 24 hour precipitation event.
(1) Peak flow for 10-year, 24-hour precipitation event (1.4" of rain)
(2) Diversion bottom width
(3) Flow depth D = ( Qn )0.375 (Manning's n = 0.03)
Ks1/2
(4) Flow velocity v = Q/A
(5) Manning's n = 0.06

[T4-8-3] 07/23
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