&EPA
United States
Environmental Protection
Agency
Office of Water
(4203)
EPA833-F-00-014
January 2001
Fact Sheet 3.1
Storm Water Phase
Final Rule
Storm Water Phase II
Final Rule
Fact Sheet Series
Overview
1.0-Storm Water Phase II
Proposed Rule Overview
Small MS4 Program
2.0 - Small MS4 Storm Water
Program Overview
2.1 - Who's Covered? Designation
and Waivers of Regulated Small
MS4s
2.2 - Urbanized Areas: Definition
and Description
Minimum Control Measures
2.3 - Public Education and
Outreach
2.4 - Public Participation/
Involvement
2.5 - Illicit Discharge Detection
and Elimination
2.6 - Construction Site Runoff
Control
2.7 - Post-Construction Runoff
Control
2.8 - Pollution Prevention/Good
Housekeeping
2.9 - Permitting and Reporting:
The Process and Requirements
2.10-Federaland State-
Operated MS4s: Program
Implementation
Construction Program
3.0 - Construction Program
Overview
3.1 -Construction Rainfall
Erosivity Waiver
Industrial" No Exposure"
4.0 - Conditional No Exposure
Exclusion for Industrial Activity
Construction Rainfall Erosivity
Waiver
The 1972 amendments to the Federal Water Pollution Control Act, later referred to as the Clean
Water Act (CWA), prohibit the discharge of any pollutant to navigable waters of the United States
unless the discharge is authorized by a National Pollutant Discharge Elimination System (NPDES)
permit. Because construction site storm water runoff can contribute significantly to water quality
problems, the Phase I Storm Water Rule imposed a requirement that all construction sites with a
planned land disturbance of 5 acres or more obtain an NPDES permit and implement storm water
runoff control plans. Phase II extends the requirements of the storm water program to sites of
between 1 and 5 acres. The Rainfall erosivity waiver, along with the water quality waiver, allows
permitting authorities to waive those sites that do not have adverse water quality impacts.
What is Erosivity?
Erosivity is the term used to describe the potential for soil to wash off disturbed, devegetated earth
into waterways during storms. The potential for erosion is in part determined by the soil type
and geology of the site. For instance, dense, clay-like soils on a glacial plain will erode less readily
when it rains than will sandy soils on the side of a hill. Another important factor is the amount and
force of precipitation expected during the time the earth will be exposed. While it is impossible to
predict the weather several months in advance of construction, for many areas of the country, there
are definite optimal periods, such as a dry season when rain tends to fall less frequently and with less
force. When feasible, this is the time to disturb the earth, so that the site is stabilized by the time the
seasonal wet weather returns. There are many other important factors to consider in determining
erosivity, such as freeze/thaw cycles and snow pack.
How Is Site Erosivity Determined?
The method for determining if a site qualifies for the erosivity waiver is based on the Universal Soil
Loss Equation (USLE) developed by the U.S. Department of Agriculture (USDA) in the 1950s to
help farmers conserve their valuable topsoil. The USLE has been updated to the Revised USLE
(RUSLE). Using a computer model supported by decades worth of soil and rainfall data, USDA
established estimates of annual erosivity values (R) for sites throughout the country. These R factors
are used as surrogate measures of the impact that rainfall had on erosion from a particular site. They
have been mapped using isoerodent contours, as shown in Figures 2 through 5.
USDA developed the Erosivity Index Table (El Table, provided here in Table 1), to show how the
annual erosivity factor is distributed throughout the year in two-week increments. Table 1 is based on
120 rainfall distribution zones for the continental U.S. Detailed instructions for calculating a project
R Factor are provided later in this fact sheet.
The Storm Water Phase II rule allows permitting authorities to waive NPDES requirements for small
construction sites if the value of the rainfall erosivity factor is less than 5 during the period of
construction activity (see § 122.26(b)(15)(i)(A)). Note that the permitting authority has the option to
not allow waivers for small construction activity. If the permitting authority in a State chooses to use
the rainfall erosivity waiver, it will not become effective until permits are required from small
construction activity.
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Fact Sheet 3.1 - Construction Rainfall Erosivity Waiver
Page 2
If the R Factor for the period of construction calculates to 5 or
lower, and the permitting authority allows the use of the waiver,
the site owner may apply for a waiver under the low rainfall
erosivity provision of the applicable NPDES Construction
General Permit. When applying, owners are encouraged to
consider other site-specific factors, such as proximity to water
resources and the sensitivity of receiving waters to sedimentation
impacts. The small construction operator must certify to the
permitting authority that the construction activity will take place
during a period when the rainfall erosivity factor is less than 5.
The start and end dates used for the construction activity will be
the initial date of disturbance and the anticipated date when the
site will have achieved final stabilization as defined by the
permit. If the construction continues beyond this period, the
operator will need to recalculate the El for the site based on this
new ending date (but keeping the old start date) and either
resubmit the certification form or apply for NPDES permit
coverage.
What Other Factors Can Affect Waiver Availability
and Eligibility?
EPA has established the R Factor of 5 or lower as the criteria
for determining waiver eligibility. However, since the intent
is to waive only those construction activities that will not
adversely impact water quality, State and Tribal permitting
authorities have considerable discretion in determining where,
when, and how to offer it. They can establish an R Factor
threshold lower than 5, or they can suspend the waiver within an
area where watersheds are known to be heavily impacted by, or
sensitive to, sedimentation. They can also suspend the waiver
during certain periods of the year. They may opt not to offer the
waiver at all. NOTE: This waiver is not available to sites that
will disturb more than 5 acres of land (large construction).
What if My Site Is Not Eligible?
If your site is not eligible for a waiver, you must submit a Notice
of Intent under the NPDES General Permit, and comply with
its requirements. These requirements are described in more
detail in Storm Water Phase II Fact Sheet 3.0.
How Do I Compute the R Factor for My Project?
1. Estimate the construction start date. This is the day you
expect to begin disturbing soils, including grubbing,
stockpiling, excavating, and grading activities. Pick the 15-
day period for your start date (e.g., June 1-15.)
2. Estimate the day you expect to have a permanent vegetative
cover of at least 70%, or as defined by your permitting
authority, over all previous disturbed areas. Round to the
nearest 15-day period.
3. Refer to Figure 1 to find your Erosivity Index (El) Zone
based on your geographic location.
4. Refer to Table 1, the Erosivity Index (El) Table. Find the
number of your El Zone in the left column. Locate the El
values for the 15-day periods that correspond to the project
start and end periods you identified in Steps 1 and 2.
Subtract the start value from the end value to find the % El
for your site. The maximum annual El value for a project is
100%.
5. Refer to the appropriate Isoerodent Map (Figures 2 through
5). Interpolate the annual isoerodent value for your area.
This is the annual R Factor for your site.
6. Multiply the percent value obtained in Step 4 by the annual
isoerodent value obtained in Step 5. This is the R Factor for
your scheduled project.
Examples
1. Construction started and completed in one
calendar year.
Find the R value of a construction site in Denver, Colorado.
Assume the site -will be disturbed from March 1 to May 15.
The El distribution zone is 84 (Figure 1). Referring to Table 1,
the project period will span from March 1 to May 15. The
difference in values between these two periods is 4.7 % (4.9-0.2
=4.7). Since the annual erosion index for this location is about
45 (interpolated from Figure 2), the R Factor for the scheduled
construction project is 4.7% of 45, or 2.1.
Because 2.1 is less than 5, the operator of this site would be
able to seek a waiver under the low rainfall erosivity provision.
2. Construction spanning two calendar years.
Find the R value for a construction site in Pittsburgh,
Pennsylvania. Assume the site -will be disturbed from August 1
to April 15.
The El distribution zone is 111 (Figure 1). Referring to Table
1, the project will span from August 1 to April 15. The
difference in values between August 1 and December 30 is 35%
(100- 65.0 = 35.0). The difference between January 1 and April
15 is 8%. The total percentage El for this project is 43% (35 +
8). Since the annual erosion index for this location is 112
(interpolated from Figure 2), the R Factor for the scheduled
construction is 43% of 112, or 48.
Since 48 is greater than 5, the operator of this site would not be
able to seek a waiver under the low rainfall erosivity provision.
-------
Fact Sheet 3.1 - Construction Rainfall Erosivity Waiver
Page 3
Can I Use A Personal Computer to Calculate the R
Factor?
The computer program used by USDA to develop the current R
Factor maps and table is called the Revised Universal Soil
Loss Equation, or RUSLE. The current version of RUSLE (v.
1.60) will calculate the R factor for the entire year for a limited
number of cities in the U.S., but does not allow the R factor to be
easily adjusted based on a shorter period of construction. If you
are interested in using RUSLE; Version 1.06 for Mined Lands,
Construction Sites, and Reclaimed Lands, is downloadable free of
charge from the Internet at http://www.sedlab.olemiss.edu/rusle.
Where Can I Get Help?
A copy of "Chapter 2, Rainfall-Runoff Erosivity Factor (R)"
from the USDA Handbook 703 - Predicting Soil Erosion by
Water: A Guide to Conservation Planning With the Revised
Universal Soil Loss Equation (RUSLE), January 1997, is
available on EPA's web site at http://www.epa.gov/npdes/stormwater.
Your local soil conservation district office can provide
assistance with R Factors and other conservation-related
issues. To find the office nearest you, look in the
government section of the phone book under soil
conservation district, conservation district, natural resource
conservation district, etc.
For Additional Information
Reference Documents
Storm Water Phase II Final Rule Fact Sheet Series
Internet: cfpub.epa.gov/npdes/stormwater/swfinal.cfm
• Storm Water Phase II Final Rule(64 FR 68722)
Internet: www.epa.gov/npdes/regulations/phase2.pdf
Contact the U.S. EPA Water Resource Center
• Phone: (202) 564-9545
Agricultural Handbook Number 703, Predicting Soil
Erosion by Water: A Guide to Conservation Planning
With the Revised Universal Soil Loss Equation
(RUSLE), Chapter 2, pp. 21-64, January 1997.
Internet: www.epa.gov/npdes/pubs/ruslech2.pdf
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Fact Sheet 3.1 - Construction Rainfall Erosivity Waiver
Page 4
Figure 1. Erosivity Index Zone Map
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Fact Sheet 3.1 - Construction Rainfall Erosivity Waiver
Page 5
Figure 2. Isoerodent Map of the Eastern U.S.
Note: Units for all maps on this page are are hundreds
-------
Fact Sheet 3.1 - Construction Rainfall Erosivity Waiver
Page 6
Figure 3. Isoerodent Map of the Western U.S.
Note: Units for all maps on this page are are hundreds
-------
Fact Sheet 3.1 - Construction Rainfall Erosivity Waiver
Page 7
Figure 4. Isoerodent Map of California
Note: Units for all maps on this page are are hundreds ft«tonf«in(ac«h«yr)"
-------
Fact Sheet 3.1 - Construction Rainfall Erosivity Waiver
PageS
Figure 5. Isoerodent Map of Oregon and Washington
Note: Units for all maps on this page are are hundreds
-------
Table 1. Erosivity Index Table
EI as a percentage of Average Annual R Value Computed for Geographic Areas Shown in Figure 1
El#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Jan
1-15
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Jan
16-31
4.3
4.3
7.4
3.9
2.3
0.0
0.0
0.0
0.8
0.3
5.4
3.5
0.0
0.7
0.0
0.0
0.0
0.0
1.0
9.8
7.5
1.2
7.9
12.2
9.8
2.0
0.0
0.0
0.6
0.0
Feb
1-15
8.3
8.3
13.8
7.9
3.6
0.0
0.0
0.0
3.1
0.5
11.3
7.8
0.0
1.8
0.0
0.0
0.0
0.0
2.6
18.5
13.6
1.6
15.0
23.6
20.8
5.4
0.0
0.0
0.7
0.0
Feb
16-29
12.8
12.8
20.9
12.6
4.7
0.5
0.0
0.0
4.7
0.9
18.8
14.0
1.8
3.3
0.5
0.5
0.7
0.6
7.4
25.4
18.1
1.6
20.9
33.0
30.2
9.8
1.0
0.0
0.7
0.0
Mar
1-15
17.3
17.3
26.5
17.4
6.0
2.0
0.0
0.0
7.4
2.0
26.3
21.1
7.2
6.9
2.0
2.0
2.8
2.5
16.4
30.2
21.1
1.6
25.7
39.7
37.6
15.6
4.0
0.2
0.7
0.0
Mar
16-31
21.6
21.6
31.8
21.6
7.7
4.1
1.2
0.9
11.7
4.3
33.2
27.4
11.9
16.5
4.4
5.5
6.1
6.2
23.5
35.6
24.4
1.6
31.1
47.1
45.8
21.5
5.9
0.5
1.5
0.2
Apr
1-15
25.1
25.1
35.3
25.2
10.7
8.1
4.9
3.6
17.8
9.2
37.4
31.5
16.7
26.6
8.7
12.3
10.7
12.4
28.0
38.9
27.0
1.6
35.7
51.7
50.6
24.7
8.0
1.5
3.9
0.8
Apr
16-30
28.0
28.0
38.5
28.7
13.9
12.6
8.5
7.8
22.5
13.1
40.7
35.0
19.7
29.9
12.0
16.2
12.9
16.4
31.0
41.5
29.4
2.2
40.2
55.9
54.4
26.6
11.1
3.3
6.0
2.8
May
1-15
30.9
30.9
40.2
31.9
17.8
17.6
13.9
15.0
27.0
18.0
42.5
37.3
24.0
32.0
16.6
20.9
16.1
20.2
33.5
42.9
31.7
3.9
43.2
57.7
56.0
27.4
13.0
7.2
10.5
7.9
May
16-31
34.9
34.9
41.6
35.1
21.2
21.6
19.0
20.2
31.4
22.7
44.3
39.8
31.2
35.4
21.4
26.4
21.9
23.9
37.0
44.0
34.6
4.6
46.2
58.6
56.8
28.0
14.0
11.9
17.9
14.2
Jun
1-15
39.1
39.1
42.5
38.2
24.5
25.5
26.1
27.4
36.0
29.2
45.4
41.9
42.4
40.2
29.7
35.2
32.8
29.3
41.7
45.2
37.3
6.4
47.7
58.9
57.1
28.7
14.6
17.7
28.8
24.7
Jun
16-30
42.6
42.6
43.6
42.0
28.1
29.6
35.4
38.1
41.6
39.5
46.5
44.3
55.0
45.1
44.5
48.1
45.9
37.7
48.1
48.2
39.6
14.2
48.8
59.1
57.1
29.8
15.3
21.4
36.6
35.6
Jul
1-15
45.4
45.4
44.5
44.9
31.1
34.5
43.9
49.8
46.4
46.3
47.1
45.6
60.0
51.9
56.0
58.1
55.5
45.6
51.1
50.8
41.6
32.8
49.4
59.1
57.2
32.5
17.0
27.0
43.8
45.4
Jul
16-31
48.2
48.2
45.1
46.7
33.1
40.0
48.8
57.9
50.1
48.8
47.4
46.3
60.8
61.1
60.8
63.1
60.3
49.8
52.0
51.7
43.4
47.2
49.9
59.2
57.6
36.6
23.2
37.1
51.5
52.2
Aug
1-15
50.8
50.8
45.7
48.2
35.3
45.7
53.9
65.0
53.4
51.1
47.8
46.8
61.2
67.5
63.9
66.5
64.0
53.3
52.5
52.5
45.4
58.8
50.7
59.2
58.5
44.9
39.1
51.4
59.3
58.7
Aug
16-31
53.0
53.0
46.4
50.1
38.2
50.7
64.5
75.6
57.4
57.2
48.3
47.9
62.6
70.7
69.1
71.9
71.2
58.4
53.6
54.6
48.1
69.1
51.8
59.3
59.8
55.4
60.0
62.3
68.0
68.5
Sep
1-15
56.0
56.0
47.7
53.1
43.2
55.6
73.4
82.7
61.7
64.4
49.4
50.0
65.3
72.8
74.5
77.0
77.2
64.3
55.7
57.4
51.3
76.0
54.1
59.5
62.2
65.7
76.3
70.6
74.8
77.6
Sep
16-31
60.8
60.8
49.4
56.6
48.7
60.2
77.5
86.8
64.9
67.7
50.7
52.9
67.6
75.4
79.1
81.6
80.3
69.0
57.6
58.5
53.3
82.0
57.7
60.0
65.3
72.6
86.1
78.8
80.3
84.5
Oct
1-15
66.8
66.8
52.8
62.2
57.3
66.5
80.4
89.4
69.7
71.1
53.6
57.9
71.6
78.6
83.1
85.1
83.1
75.0
61.1
60.1
56.6
87.1
62.8
61.4
67.5
77.8
89.7
84.6
84.3
88.9
Oct
16-31
71.0
71.0
57.0
67.9
67.8
75.5
84.8
93.4
79.0
77.2
57.5
62.3
76.1
81.9
87.0
88.4
87.7
86.6
65.8
63.2
62.4
96.7
65.9
63.0
68.2
84.4
90.4
90.6
88.8
93.7
Nov
1-15
75.7
75.7
64.5
75.2
77.9
85.6
89.9
96.3
89.6
85.1
65.5
69.3
83.1
86.4
90.9
91.5
92.6
93.9
74.7
69.6
72.4
99.9
70.1
66.5
69.4
89.5
90.9
94.4
92.7
96.2
Nov
16-31
82.0
82.0
73.1
83.5
86.0
95.9
96.6
99.1
97.4
92.5
76.2
81.3
93.3
93.6
96.6
96.3
97.2
96.6
88.0
76.7
81.3
99.9
77.3
71.8
74.8
93.9
93.1
97.9
98.0
97.6
Dec
1-15
89.1
89.1
83.3
90.5
91.3
99.5
99.2
100.0
100.0
96.5
87.4
91.5
98.2
97.7
99.1
98.7
99.1
98.0
95.8
85.4
88.9
99.9
86.8
81.3
86.6
96.5
96.6
99.3
99.8
98.3
Dec
16-31
95.2
95.2
92.3
96.0
96.9
99.9
99.7
100.0
100.0
99.0
94.8
96.7
99.6
99.3
99.8
99.6
99.8
100.0
98.7
92.4
94.7
99.9
93.5
89.6
93.0
98.4
99.1
100.0
99.9
99.6
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Table 1. Erosivity Index Table (cont.)
El#
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Jan
1-15
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Jan
16-31
0
0.1
0
0
0
0
0
0
0
0
0.1
0
0
1.7
0.2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Feb
1-15
0
0.1
0
0
0
0
0
0
0
0
0.2
0
0
2.3
0.2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Feb
16-29
0
0.1
0
0
0
0
0
1.1
0
0
0.2
0
0
2.4
0.3
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Mar
1-15
0
0.1
0
0
0
0
0
4.3
0
0
0.2
0
0
2.4
0.3
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Mar
16-31
0.2
0.6
0.6
1.8
2.5
0.9
0
7.2
1.6
1.5
0.2
0
0
2.4
0.4
0
0
0
0
0.1
0.3
0
0
0.2
0
0
0
0.2
0
0
Apr
1-15
1
2.2
2.3
7.3
10.2
3.4
0
11
6.5
6.2
0.2
0
0
2.4
0.6
0
0
0
0
0.4
1
0
0
0.7
0
0
0.1
0.9
0
0
Apr
16-30
3.5
4.3
4.2
10.7
15.9
6.7
1
13.9
11
10.1
0.4
0.2
0.1
2.7
0.8
0.6
0.4
0
0.7
2.4
3.1
0.6
0.8
2.4
1.3
1.3
1
2.9
2.2
0.4
May
1-15
9.9
9
8.8
15.5
22.2
12.7
3.9
17.9
17.8
16.3
1.1
0.9
0.4
3.5
1.4
2.6
1.6
0
2.7
8.2
8.7
2.5
3
7.2
5.4
5.1
3.5
8
8.9
1.5
May
16-31
15.7
14.2
16.1
22
27.9
18.5
9.1
22.3
24.7
23.3
6.8
5.2
2.7
7.6
3.7
7.5
5.8
2
8.3
13.7
18.8
6.8
9.5
14.7
13.3
11.4
9.2
13.2
15.6
4
Jun
1-15
26.4
23.3
30
29.9
34.7
26.6
19.1
30.3
33.1
32.5
22.9
17.3
9.5
18.5
10.2
19.6
17
8.1
20
23.8
35.8
17.5
24.2
27.2
25.5
22.3
21.5
21
24.2
9.5
Jun
16-30
47.2
34.6
46.9
35.9
43.9
36.3
26.7
43.1
42.8
42.2
40.1
33.8
21.9
34.3
22.6
32.9
33
15.4
27.5
38.8
49.6
29.8
35.3
37.2
31.6
29.5
31
29.1
31.1
13.3
Jul
1-15
61.4
46.3
57.9
42
51.9
46
36.3
55.1
50.3
50.1
54.9
53.2
42.7
52.5
41.8
48.9
52.5
27.8
35.6
55.1
60.4
46.1
48
47.3
38.8
38.5
43.5
38
38.3
20.5
Jul
16-31
65.9
54.2
62.8
48.5
56.9
53.5
47.9
61.3
54.9
55.6
63.8
66.5
58.6
64
54
63
66.4
40.7
44.6
66.1
70.2
60.5
63.1
58.8
52.5
51.1
60.4
45.9
46
33.6
Aug
1-15
69
61.7
66.2
56.9
61.3
60.2
61.4
65.7
59.7
60.5
70.7
75.9
71.1
72.3
64.5
73.5
75.7
52.6
56
73.6
77
72.7
76.1
67.6
66.8
65.2
75.1
54.5
54.9
52.8
Aug
16-31
77.2
72.9
72.1
67
67.3
68.3
75.1
72.1
68.9
67.5
81.5
87.6
84.6
83.3
78.7
83.3
85.5
61.1
70.2
81.8
84
86
87.7
74
75.5
77.8
86.1
65.4
64.2
66.5
Sep
1-15
86
82.5
79.1
76.9
73.9
75.8
84.5
77.9
78.1
74.3
89.8
93.7
91.9
90
88.4
89.5
91.3
69.3
81.3
87.7
88.8
92.8
93.5
79.2
81.2
85.6
91.6
74.8
73.2
76.7
Sep
16-31
91.6
89.6
85.9
85.8
80.1
82.6
92.3
82.6
83.6
79.4
96.3
97.5
97.1
95.1
96
95.6
96.5
82.6
89.2
93.8
93.8
96.8
97.2
86.7
87.9
91.7
96.2
82.1
81.9
88.1
Oct
1-15
94.8
93.7
91.1
91.2
85.1
88.3
96
86.3
87.5
84.1
98.7
99
99
97.3
98.7
98.3
98.8
92
93.6
97
96.6
98.4
98.6
92.6
92.8
95
98.1
87.5
88.5
94.2
Oct
16-31
98.7
98.2
97
95.7
89.6
96.3
99.1
90.3
93
91.1
99.2
99.7
99.8
98.5
99.4
99.6
100
98
98.5
99.4
99.1
99.7
99.5
97.9
98.3
98.7
99.4
95.4
95.7
98.6
Nov
1-15
100
99.7
98.9
97.8
93.2
99.3
100
93.8
96.5
95.8
99.3
100
100
98.9
99.7
100
100
100
100
100
100
100
99.8
99.8
100
100
99.9
98.8
98.6
100
Nov
16-31
100
99.9
98.9
99.6
98.2
99.9
100
98.4
99.2
99.1
99.4
100
100
98.9
99.7
100
100
100
100
100
100
100
99.9
99.9
100
100
99.9
99.7
99.4
100
Dec
1-15
100
99.9
98.9
100
99.8
100
100
100
100
100
99.4
100
100
98.9
99.8
100
100
100
100
100
100
100
100
100
100
100
100
100
99.7
100
Dec
16-31
100
99.9
98.9
100
99.8
100
100
100
100
100
99.7
100
100
99.2
99.9
100
100
100
100
100
100
100
100
100
100
100
100
100
99.7
100
-------
Table 1. Erosivity Index Table (cont)
El#
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
Jan
1-15
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Jan
16-31
0
0
0
0
3.6
0
0
2.3
2
0.5
0.7
0
0
0
0.1
0
0.2
0
0
0.6
0.1
0
0
0
0
0
0
0
0
1
Feb
1-15
0
0
0
0
7
0
0
4.5
3.7
0.7
1.2
0
0.1
0
0.1
0
0.3
0
0
1.2
0.1
0.1
0.1
0.1
0
0
0
0
1
2
Feb
16-29
0
0.1
0
0.7
9.6
0
0
7.8
5.7
1
1.6
0
0.1
0
0.1
0
0.3
0
0
1.6
0.2
0.1
0.1
0.1
0
0
0
0
1
3
Mar
1-15
0
0.3
0
2.8
11.4
0
0
10.4
7.8
1.3
2.1
0
0.2
0
0.2
0
0.4
0
0
2.1
0.4
0.2
0.1
0.2
0
0
1
1
2
4
Mar
16-31
0
0.8
0
7.4
13
0.1
0.1
12
10.5
1.7
2.8
0
0.2
0.1
0.5
0.1
0.8
0
0.2
2.5
0.5
0.2
0.3
0.3
0
0
1
1
3
6
Apr
1-15
0
2.1
0
12.4
14.4
0.5
0.4
13.3
12.4
2.2
3.3
0.1
0.3
0.2
1.3
0.2
1.5
0.2
0.7
3.3
0.8
0.5
0.9
0.6
1
1
2
2
4
8
Apr
16-30
1.3
3.6
0.9
14.4
16.3
1.1
0.9
16.3
13.7
2.8
3.6
0.2
0.6
0.5
1.9
0.6
2
0.5
1.3
4.5
0.9
1.2
1.6
1.7
2
2
3
3
7
13
May
1-15
5
6.5
3.7
15.6
17.7
2.2
1.6
17.7
14.3
3.4
4
0.7
1.3
1.2
3
1.3
2.8
1.6
2.7
6.9
1.5
3.1
3.5
4.9
3
3
6
6
12
21
May
16-31
8.5
9.7
7.8
17.3
18.4
3.6
1.9
18.1
14.7
3.9
4.5
0.8
4.1
2.7
4.1
2
3.9
3.8
5.8
10.1
3.9
6.7
8.3
9.9
6
6
10
13
18
29
Jun
1-15
15.5
13.7
13.3
19.4
19.3
6
2.4
18.2
15.1
4.7
5.6
1.3
11.5
6.4
6.6
3.5
5.9
8.9
12.7
15.5
9.9
14.4
19.4
19.5
11
11
17
23
27
37
Jun
16-30
29.8
16.5
15.8
21
20.5
7.6
5
18.3
15.7
5.4
6.5
3.5
18.1
10.2
10
4.9
7.2
13.2
18.8
19.7
12.8
20.1
30
27.2
23
23
29
37
38
46
Jul
1-15
41.8
20.8
19.9
24.4
23.6
11.1
12.1
18.4
17.1
7.4
9.1
9.9
28.3
18.4
17.6
8.4
10.3
21.8
28.8
26.6
18.2
29.8
44
38.3
36
36
43
51
48
54
Jul
16-31
46
27.3
29
32.3
32
19.8
24.8
19.9
22.7
15.7
18.5
24.7
40.2
31
28.3
17.4
21.5
35.8
41.6
36.4
30.7
44.5
59.2
52.8
49
49
55
61
55
60
Aug
1-15
49.2
40.1
46.8
48
50
38.9
48.3
24.5
36.7
36.5
40.6
51.4
54.1
50.7
44.7
37.3
46.5
56.6
58.4
51.7
54.1
64.2
72.4
68.8
63
63
67
69
62
65
Aug
16-31
56
56.9
64.7
61.4
66.2
59.7
73.6
35
50.4
55.8
59.7
71.5
67
68.7
59.4
57.5
66.3
75.4
75.7
67.5
77.1
83.1
84.6
83.9
77
77
77
78
69
69
Sep
1-15
65.1
72.6
78.3
72.1
77.2
74.4
86.5
54.4
63.6
70.3
74
83.6
77.2
81.2
71.6
72.9
78.3
86
86.5
79.4
89
92.2
91.2
91.6
90
90
85
85
76
74
Sep
16-31
71.6
83.4
88.8
81.9
85.4
83.2
92
69.4
75
80.9
86.3
93.8
87.7
91.6
83.9
83.7
86.5
92.9
94.2
88.8
94.9
96.4
96.5
96.4
95
95
91
91
83
81
Oct
1-15
78.6
89.4
93.9
87
88.8
88.1
94.3
78.6
81.8
86.4
91.7
97.7
93.3
96.1
90.3
89.5
90.8
95.9
97.3
93.2
97.2
98.1
98.6
98.2
98
98
96
94
90
87
Oct
16-31
91.1
95.5
98.5
90.1
90.4
94.6
96.6
85.7
87.8
90.9
94.7
99.2
97.5
98.4
94.7
95.8
96
98.2
98.9
96.1
98.7
99.3
99.5
99.2
99
99
98
96
94
92
Nov
1-15
97.3
98.1
100
92.4
91.3
97.7
97.9
89.2
90.8
93.4
96
99.8
99.1
99.2
96.7
98.4
98.2
99.2
99.5
97.3
99.3
99.7
99.8
99.6
100
100
99
98
97
95
Nov
16-31
99.3
99.6
100
98.1
92.7
99.4
99.5
91.9
93.2
96.4
96.7
99.9
99.6
99.8
98.8
99.6
99.1
99.8
99.9
98.2
99.6
99.8
99.9
99.8
100
100
100
99
98
97
Dec
1-15
100
100
100
100
94.8
100
100
93.9
94.9
98.1
97.3
99.9
99.8
100
99.6
100
99.5
100
100
98.7
99.7
99.8
100
99.8
100
100
100
99
99
98
Dec
16-31
100
100
100
100
97
100
100
97
97.5
99.4
98.8
100
100
100
99.9
100
99.8
100
100
99.3
99.9
99.9
100
99.9
100
100
100
100
100
99
-------
Table 1. Erosivity Index Table (cont.)
El#
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
Jan
1-15
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Jan
16-31
0
0
1
1
1
2
1
1
0
0
0
0
1
2
1
3
3
3
3
1
1
0
1
1
1
1
1
2
1
8
Feb
1-15
0
0
1
2
3
4
3
2
0
0
0
1
2
3
3
6
5
6
6
3
2
0
2
2
2
3
2
4
2
16
Feb
16-29
0
0
2
4
5
6
5
4
1
0
1
2
3
5
6
9
7
9
10
5
3
1
3
4
3
5
3
6
4
25
Mar
1-15
1
1
3
6
7
9
7
6
1
1
2
3
4
7
9
13
10
12
13
7
4
2
4
6
4
7
4
8
6
33
Mar
16-31
1
1
4
8
9
12
10
8
2
1
3
4
6
10
12
17
14
16
16
9
5
3
5
8
5
9
5
12
7
41
Apr
1-15
1
1
6
10
11
17
14
10
3
2
4
6
8
13
16
21
18
20
19
12
6
4
6
11
6
12
7
16
9
46
Apr
16-30
2
2
8
15
14
23
20
13
5
3
6
8
10
16
21
27
23
24
23
15
8
5
8
13
8
15
9
20
12
50
May
1-15
6
6
13
21
18
30
28
19
7
5
9
11
14
19
26
33
27
28
26
18
11
7
10
11
10
18
11
25
15
53
May
16-31
16
16
25
29
27
37
37
26
12
9
14
15
18
23
31
38
31
33
29
21
15
12
12
13
14
21
14
30
18
54
Jun
1-15
29
29
40
38
35
43
48
34
19
15
20
22
25
27
37
44
35
38
33
25
20
17
17
21
19
25
17
35
23
55
Jun
16-30
39
39
49
47
41
49
56
42
33
27
28
31
34
34
43
49
39
43
39
29
28
24
22
26
26
29
22
41
31
56
Jul
1-15
46
46
56
53
46
54
61
50
48
38
39
40
45
44
50
55
45
50
47
36
41
33
31
32
34
36
31
47
40
56.5
Jul
16-31
53
53
62
57
51
58
64
58
57
50
52
49
56
54
57
61
53
59
58
45
54
42
42
38
45
45
42
56
48
57
Aug
1-15
60
60
67
61
57
62
68
63
65
62
63
59
64
63
64
67
60
69
68
56
65
55
52
46
56
56
54
67
57
57.75
Aug
16-31
67
67
72
65
62
66
72
68
72
74
72
69
72
72
71
71
67
75
75
68
74
67
60
55
66
68
65
75
63
58
Sep
1-15
74
74
76
70
68
70
77
74
82
84
80
78
79
80
77
75
74
80
80
77
82
76
68
64
76
77
74
81
72
58.75
Sep
16-31
81
81
80
76
73
74
81
79
88
91
87
85
84
85
81
78
80
84
83
83
87
83
75
71
82
83
83
85
78
60
Oct
1-15
88
88
85
83
79
78
86
84
93
95
91
91
89
89
85
81
84
87
86
88
92
89
80
77
86
88
89
87
88
61
Oct
16-31
95
95
91
88
84
82
89
89
96
97
94
94
92
91
88
84
86
90
88
91
94
92
85
81
90
91
92
89
92
63
Nov
1-15
99
99
97
91
89
86
92
93
98
98
97
96
95
93
91
86
88
92
90
93
96
94
89
85
93
93
95
91
96
66.5
Nov
16-31
99
99
98
94
93
90
95
95
99
99
98
98
97
95
93
90
90
94
92
95
97
96
92
89
95
95
97
93
97
72
Dec
1-15
100
100
99
96
96
94
98
97
100
99
99
99
98
96
95
94
93
96
95
97
98
98
96
93
97
97
98
95
98
80
Dec
16-31
100
100
99
98
98
97
99
99
100
100
100
100
99
98
97
97
95
98
97
99
99
99
98
97
99
99
99
97
99
90
-------
Table 1. Erosivity Index Table (cont)
0
El#
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
Jan
1-15
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Jan
16-31
7
4
4
7
9
8
8
9
10
8
10
8
12
7
11
10
11
8
10.6
0.2
10.7
2.7
8.7
4.3
11.7
4.8
0
5.5
2.4
Feb
1-15
14
8
9
12
16
15
15
16
20
15
18
16
22
15
21
18
22
14
21.2
0.3
21.4
5.5
17.5
8.6
23.3
9.6
4.7
11
4.9
Feb
16-29
20
12
15
17
23
22
22
22
28
22
25
24
31
22
29
25
31
20
28.6
0.3
28.7
5.7
25.2
9.3
33.5
13.1
9.4
19.2
7.4
Mar
1-15
25.5
17
23
24
30
28
29
27
35
28
29
32
39
30
37
30
39
25
36
0.3
36
5.9
33
10.1
43.7
16.5
10.8
27.5
9.9
Mar
16-31
33.5
23
29
30
37
33
34
32
41
33
33
40
45
37
44
39
46
32
41.4
0.3
41.7
7.1
39.9
11.1
50.7
22.6
12.2
36.6
11.7
Apr
1-15
38
29
34
39
43
38
40
37
46
38
36
46
49
43
50
46
52
37
46.8
0.3
47.3
8.4
46.7
12
57.6
28.7
13.2
45.7
13.6
Apr
16-30
43
34
40
45
47
42
45
41
49
41
39
51
52
49
55
51
56
42
49.3
0.8
50.3
10
50.8
15.3
60.3
30.8
14.3
47.8
14.6
May
1-15
46
38
44
50
50
46
48
45
51
44
41
54
54
53
57
54
58
47
51.8
1.3
53.2
11.7
54.8
18.6
63
32.8
14.9
50
15.6
May
16-31
50
44
48
53
52
50
51
48
53
47
42
56
55
55
59
57
59
50
52.5
5.3
54.5
15.3
56.2
22.7
63.5
33.3
15.5
50.9
16.2
Jun
1-15
52.5
49
50
55
54
52
54
51
55
49
44
57
56
57
60
58
60
53
53.2
9.3
55.7
19
57.6
26.7
64.1
33.8
24.2
51.7
16.8
Jun
16-30
54.5
53
51
56
55
53
57
53
56
51
45
58
56
58
60
59
61
55
53.5
30.1
56.2
22.6
58
28.7
64.2
34
32.8
52.1
17.2
Jul
1-15
56
56
52
57
56
53
59
55
56
53
46
58
56
59
60
59
61
56
53.7
50.8
56.7
26.1
58.4
30.7
64.2
34.2
45.5
52.5
17.7
Jul
16-31
58
59
53
58
57
53
62
56
57
55
47
59
56
60
60
60
61
58
53.9
56.8
56.9
29
58.9
31.3
64.5
36.4
58.2
54.2
24.7
Aug
1-15
59
62
55
59
58
53
63
57
58
56
48
59
57
61
61
60
61
59
54
62.9
57
31.9
59.4
32
64.8
38.6
67.9
55.9
31.7
Aug
16-31
60
65
57
61
59
54
64
57
59
58
49
60
57
62
61
60
62
61
54.3
67.5
57.4
36.6
60.8
34
66.1
43
77.6
60.1
46.9
Sep
1-15
61.5
69
60
62
60
55
65
58
60
59
51
60
57
63
61
61
62
63
54.7
72.2
57.8
41.2
62.3
36
67.3
47.5
86.3
64.4
62.1
Sep
16-31
63
72
62
63
62
57
66
59
61
60
53
61
57
65
62
62
62
64
55.7
75.8
59
46
64.1
44.4
68.6
56
95.1
70.5
67
Oct
1-15
65
75
64
64
64
59
67
61
62
63
56
62
58
67
63
63
63
66
56.8
79.4
60.2
50.7
65.9
52.9
69.8
64.5
95.6
76.7
72
Oct
16-31
68
79
67
66
67
63
69
64
65
65
59
64
59
70
64
64
64
68
61.6
85.6
64.1
62.3
68.8
60.1
70.7
66.2
96.1
81.2
80.7
Nov
1-15
72
83
72
70
71
68
72
68
69
69
64
68
62
74
67
67
66
71
65.3
91.7
67.9
73.9
71.7
67.3
71.6
67.9
98
85.7
89.3
Nov
16-31
79
88
80
77
77
75
76
73
74
75
70
74
68
79
71
72
71
76
73.9
95.9
76.1
83.5
78.6
78.2
79.2
77.9
100
90.4
92.3
Dec
1-15
86
93
88
84
86
83
83
79
81
84
80
83
77
85
78
80
78
85
82.5
100
84.2
93.1
85.5
89.2
86.7
88
100
101
95.3
Dec
16-31
93
96
95
92
93
92
91
89
90
92
90
91
88
92
89
90
89
93
91.2
100
92.1
96.6
92.7
94.6
93.4
94
100
97.6
97.7
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