FLOOD09931

• County: Statewide
• Community: Urbanizing Areas of Colorado
• Basin: Statewide
• Title: A Guide for Erosion & Sediment Control in Urbanizing Areas of Colorado
• Date: 1/1/1973
• Prepared For: State of Colorado
• Prepared By: USDA Soil Conservation Service
• Floodplain - Doc Type: Educational/Technical/Reference Information

FIGURE 9
Values of the Topographic Factor -"LS"

length Percent Slope (S)
of
Slope (l)
Ft. 0.2 0.3 0.4 0.5 1.0 2.0 3,0 4.0 5.0 6.0 8,0 10.0 12,0 14.0 16.0 18.0 20.0 25.0 30,0 40,0 50.0 60.0
20 .05 .05 .06 .06 .08 .12 .18 .21 .24 .30 .44 .61 .81 1.0 1.3 1.6 1.8 2.6 3.5 5.5 8 10
40 .06 .07 .07 .08 .10 .15 .22 .28 .34 .43 .63 .87 1.2 1.4 1.8 2.2 2.6 3.5 5.0 8 11 15
60 .07 .08 .08 .08 .11 .17 .25 .33 .41 .5? .77 1.0 1.4 1.8 2.2 2.6 3.0 4.5 6.0 10 14 18
80 .08 .08 .09 .09 .12 .19 .27 .37 .48 .60 .89 1.2 1.6 2.0 2.6 3.0 3.5 5.5 7 11 16 21
100 .08 .09 .09 .10 .13 .20 .29 .40 .54 .67 .99 1.4 1.5 2.2 2.8 3.5 4.0 6.0 8 13 18 23
110 .08 .09 .10 .10 .13 .21 .30 .42 .56 .71 1.0 1.3 1.8 ].3 2.0 3.5 4.5 6.0 8 13 19 24
120 .09 .09 .10 .10 .14 .21 .30 .43 .59 .74 1.0 1.6 2.0 2.6 3.0 4.0 4.5 6.0 9 14 20 25
130 .09 .09 .10 .11 .14 .22 .31 .44 .61 ,77 1.2 1.6 2.0 2.6 3.0 4.0 4.5 7 9 14 20 26
140 .09 .10 .10 .11 .14 .22 .32 .46 .63 .80 1.2 1.6 2.2 2.8 3.5 4.0 5.0 7 9 15 21 27
150 .09 .10 .11 ' .11 .15 .23 .32 .47 .66 .82 1.2 1.6 2.2 2.8 3.5 4.0 5.0 7 10 15 22 28
160 .09 .10 .11 .11 .15 .23 .33 .48 .68 .85 1.2 1.8 2.2 3.0 3.5 4.5 5.0 7 10 16 23 29
180 .10 .10 .11 .12 .15 .24 .34 .51 .72 .90 1.4 1.8 2.4 3.0 4.0 4.5 5.5 8 11 17 24 31
200 .10 .11 .11 .12 .16 .25 .35 .53 .76 .95 1.4 2.0 2.6 3.0 4.0 5.0 6.0 8 11 18 25 33
JOO .11 .12 .13 .14 .18 .28 .40 .62 .93 1.2 1.8 .24 3.0 4.0 5.0 6.0 7 10 14 22 31 40 0\
N
400 .12 .13 .14 .15 .20 .31 .44 .70 1.0 1.4 2.0 2.8 3.5 4.5 5.5 7 8 12 16 25 36 46
500 .13 .14 .15 .16 .21 .33 .47 .76 1.2 1.6 2,2 3.0 4.0 5.0 6.0 8 9 13 18 28 40 52
600 .14 .15 .16 .17 .22 .34 .49 .82 1.4 1.6 2.4 3.5 4.5 5.5 7 8 10 14 19 31 44 57
700 .15 .16 .17 .18 .23 .36 .52 .87 1.4 1.8 2,6 3.5 5.0 6.0 8 9 11 16 21 33 47 61
800 .15 .16 .17 .18 .24 .38 .54 .92 1.6 2.0 2.8 4.0 5.0 6.0 8 10 12 17 22 36 50 65
900 .16 .17 .18 .19 .25 .39 .56 .96 1.6 2.0 3.0 4.0 5.5 7 9 10 12 18 24 38 53 69
1000 .16 .18 .19 .20 .26 .40 .57 1.0 1.6 2.2 3.0 4.5 5.5 7 9 11 13 19 25 40 56 73
1100 .17 .18 .19 .20 .27 .41 .59 1.0 1.8 2,2 3.5 4.5 6.0 8 9 11 14 20 26 42 59 77
1200 .17 .18 .20 .21 .27 .42 .81 .10 .18 2.4 3.5 4.5 6.0 8 10 12 14 20 28 44 62 80
1300 .18 .19 .20 .21 .28 .43 .82 1.2 2.0 2.4 3.5 5.0 7 8 10 12 15 21 29 46 64 83
1400 .18 .19 .21 .22 .29 .44 .63 1.2 2.0 2.6 3.5 5.0 7 9 11 13 15 22 30 47 67 87
1500 .19 .20 .21 .22 .29 .45 .65 1.2 2.0 2.6 4,0 5.5 7 9 11 13 16 23 31 49 69 90
1600 .19 .20 .21 .23 .30 .46 .66 1.2 2.2 2.6 4.0 5.5 7 9 11 14 16 24 32 51 71 93
1700 .19 A21 .22 .23 .30 .47 .67 1.2 2.2 2.8 4.0 5.5 7 9 12 14 17 24 33 52 73 95
2000 .20 .22 .23 .24 .32 .49 .71 1.4 2.4 3.0 4.5 6.0 8 10 13 15 18 26 36 57 80 104
Countour limits - 2 percent 400 feet. 8 percent 200 feet. 10 percent 100 feet. 14 - 24 percent 60 feet. The effectiveness
of contouring beyond these limits is speculative.
When the length of slope exceeds 400 feet and (or) percent of slope exceeds 24 percent. soil loss estimates are speculative
IS these values are beyond the range of research data.