APPCOR13152

• Permit No: C1981031
• IBM Index Class Name: Application Correspondence
• Doc Date: 9/30/1983
• Doc Name: STIPULATION NO. 3 RESPONSES
• From: J F SATO & ASSOCIATES
• To: MLRD
• Media Type: D
• Archive: No

EXHIBIT B
Sediment Calculations
Reference: National Cooperative Highway Research Program
Report 221, Transportion Research Board, Apri1.1980. .
General equation: A R x K x LS x VM
R: From Figure 5.2, R is 70 for the 2-yr recurrence
interval. For the 10-yr recurrence interval,
Figure 2.2 gives an EI/R of 1.65, for an R10 of
116.
K: From Figure 2.2 (attached) using the result of the
soil sample in the Manzano and Louviers/Travessilla
soils, K 0.25. This is low for the area, uae 0.30
LS:From Figure 2.3 (attached), with elope of 7.5% and
flow line of 400 feet: LS = 2.
VM: From Figure 2.8, with grass of 5% and less than 25%
weeds, VM = 0.35.
Then
and
A= 70x .30x2x .35
= 14.7 tons/acre/year (2-yr rec. int.)
A 116 x .30 x 2 x .35
= 24.4 tons/acre/yr (10-yr rec. int.)
Converting to acre-feet using a soil density of 95
ibs/cu. ft:
14.7t/yr/acre x 2.1 acre x 20001bs x 1 cu ft =650 cu.ft.
ton ~-I~
650 cu. ft./43560 sq ft/ac = 0.015 AF
24.4t/yr/acre x 2.1 acre x 20001bs x 1 cu ft =1080 cu.ft.
ton ~5~b
1080 cu. ft./ 43560 sq ft/ac = 0.025 AF
Assume that pond is cleaned every year and that the
10-year flow event occurs at the end of the year used for
the 10-year recurrence interval in the sediment analysis.
Thus use 0.025, rounded to 0.03 AFB as the sediment
volume.