User Manual
Watershed Area
sq mi
1 Hour Storm
Point Precipitation
in.
Areal Adjustment Factor
%
Adjusted Point Precipitation
Slope of Rainfall Intensity  Duration Curve
3 Hour Storm
Point Precipitation
in.
Areal Adjustment Factor
%
Adjusted Point Precipitation
6 Hour Storm
Point Precipitation
in.
Areal Adjustment Factor
%
Adjusted Point Precipitation
24 Hour Storm
Point Precipitation
in.
Areal Adjustment Factor
%
Adjusted Point Precipitation
Refer to Plate E5.8
Lag Time Calculator
Basin Factor  n
Length along longest watercourse  L
ft
Length along longest watercourse measured upstream
to a point opposite the centroid of the area  Lca
ft
Elevation Difference
ft
Lag Time
hr
40% Lag Time
min
Loss Rate Data
Effective Rainfall
SGraphs
Average Adjusted Loss Rate Calculator (Plate E2.1)
Average Adjusted Loss Rate (Manual Entry)
Add Loss Rate Values
AMC Condition:
I
II
III
Soil Group / Cover Type
View Chart
RI Number
Perv. Area Infiltrn Rate (in/hr)
Land Use
Imp. Area Decimal %
Adj.Infiltrn Rate (in/hr)
Area (acres)

Barren
Chapparrel, Broadleaf
Chapparrel, Narrowleaf
Fallow
Grass
Legumes, Close Seeded
Meadow or Cienegas
Open Brush
Orchards, Evergreen
Pasture, Dryland
Pasture, Irrigated
Row Crops
Small Grain
Turf
Urban Landscaping
Woodlands
Woodlands, Grass
Soil Group / Cover Type
RI Number
Perv. Area Infiltrn Rate (in/hr)
Land Use
Imp. Area Decimal %
Adj.Infiltrn Rate (in/hr)
Area (acres)
Area/ Total Area
Ave. Adj. Rate (in/hr)
Total area =
Average Soil Loss =
Unit Time Period
5
10
15
30
min (Use interval less than 40% of lag time)
Low Loss
%
Fm (Percentage of F)
(24hour Storm Only)
% (Typically 5075%)
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1 Hour
Unit Time
Effective Rainfall
3 Hour
Unit Time
Effective Rainfall
6 Hour
Unit Time
Effective Rainfall
24 Hour
Unit Time
Effective Rainfall
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SGraph 1
SGraph 2
SGraph 3
SGraph 4
Type:
Mountain
Type:
Valley
Type:
Foothill
Type:
Desert
Weight %
Weight %
Weight %
Weight %
Time in Percent of Lag
Discharge (percent)
Time in Percent of Lag
Discharge (percent)
Time in Percent of Lag
Discharge (percent)
Time in Percent of Lag
Discharge (percent)
SGraph Combined
Type:
Combined
Weight %
Time in Percent of Lag
Discharge (percent)
SGraph Combined