|
<br />i"
<br />
<br />TIME 1-Hour Design Storm - Cumulative Depth
<br />(MIN) 2-Yr 5-Yr 10-Yr 50-Yr 100-Yr
<br />0 0.000 0.000 0.000 0.000 0.000
<br />5 0.238 0,347 0.416 0.516 0,595
<br />10 0.389 0.567 0.680 0,819 0.943
<br />15 0.468 0.683 0.819 1.050 1.210
<br />20 0.511 0.746 0.895 1.181 1.360
<br />25 0.554 0.809 0,970 1,311 1.510
<br />30 0.598 0.872 1,046 1,442 1,661
<br />35 0.618 0.901 1.082 1.498 1.725
<br />40 0.638 0.931 1.117 1.555 1,790
<br />45 0.659 0.961 1,153 1.611 1,855
<br />50 0.679 0.991 1.189 1.667 1.920
<br />55 0.700 1.020 1.224 1.724 1.985
<br />60 0,720 1.050 1.260 1.780 2.050
<br />
<br />100 - Yr Storm Event, Durations Less than 1-hr
<br />From "Short duration rainfall relations for the Western United
<br />States", Arkell and Richards
<br />Ratios to 1-Hr Storm Point Rainfall
<br />- -
<br />5 min 15 min
<br />- -
<br />0.29 0,59
<br />
<br />2 - Yr Storm Event, Durations Less than 1-hr
<br />From "Short duration rainfall relations for the Western United
<br />States" I Arkell and Richards
<br />Ratios to 1-Hr Storm Point Rainfall
<br />10 min
<br />0.54
<br />
<br />5min
<br />0.33
<br />
<br />10 min
<br />0.46
<br />
<br />15 min
<br />0,65
<br />
<br />Depth
<br />30min
<br />0.81
<br />
<br />Depth
<br />30 min
<br />0.83
<br />
<br />1
<br />
<br />hr
<br />1
<br />
<br />hr
<br />1
<br />
<br />TIME 2-Hour Design Storm - Cumulative Depth
<br />(MIN) 2-Yr 5-Yr 10-Yr 50-Yr 100-Yr
<br />0 0.000 0.000 0.000 0.000 0,000
<br />5 0.014 0,021 0,025 0.023 0.021
<br />10 0.043 0.060 0,072 0,085 0.082
<br />15 0,104 0.151 0.175 0,174 0.176
<br />20 0,219 0.312 0.364 0.317 0.340
<br />25 0.399 0.574 0.679 0.584 0.627
<br />30 0.500 0.711 0.830 1.029 1.140
<br />35 0.545 0.772 0.901 1.242 1.427
<br />40 0.581 0,818 0.955 1.385 1.591
<br />45 0.603 0.856 1.003 1.474 1.718
<br />50 0.624 0.894 1.043 1,563 1.820
<br />55 0,646 0.925 1.084 1.620 1,902
<br />60 0.667 0.957 1.124 1.677 1.984
<br />65 0.689 0.988 1.164 1.734 2.066
<br />70 0.703 1.020 1.205 1.776 2.107
<br />75 0.718 1.046 1.245 1.819 2.148
<br />80 0.732 1.069 1.276 1,851 2.173
<br />85 0.747 1.092 1.300 1.883 2.198
<br />90 0.761 1.115 1.324 1.908 2.222
<br />95 0.775 1.138 1,348 1.933 2.247
<br />100 0.790 1.154 1.372 1,958 2.271
<br />105 0,804 1.170 1.396 1.983 2.296
<br />110 0.819 1,185 1 .420 2.008 2,321
<br />115 0.826 1.201 1.441 2.033 2.345
<br />120 0.833 1.215 1.458 2.058 2.370
<br />
<br />TIME
<br />(MIN)
<br />5
<br />10
<br />15
<br />20
<br />25
<br />30
<br />35
<br />40
<br />45
<br />50
<br />55
<br />60
<br />65
<br />70
<br />75
<br />80
<br />85
<br />90
<br />95
<br />100
<br />105
<br />110
<br />115
<br />120
<br />125
<br />130
<br />135
<br />140
<br />145
<br />150
<br />155
<br />160
<br />165
<br />170
<br />175
<br />180
<br />
<br />0.013
<br />0.019
<br />0.025
<br />0,034
<br />0.040
<br />0.050
<br />0.057
<br />0.066
<br />0.075
<br />0.085
<br />0.096
<br />0,106
<br />0.116
<br />0.128
<br />0.140
<br />0.153
<br />0.165
<br />0,180
<br />0.196
<br />0.211
<br />0.235
<br />0.255
<br />0.300
<br />0.363
<br />0.450
<br />0.529
<br />0,613
<br />0.690
<br />0.757
<br />0.784
<br />0.810
<br />0,828
<br />0.850
<br />0,872
<br />0.888
<br />0,905
<br />
<br />6-Hour Design Storm -
<br />Cumulative Depth
<br />- -
<br />5-Yr 100-Yr
<br />
<br />0.024
<br />0.036
<br />0.048
<br />0.065
<br />0.077
<br />0.096
<br />0.110
<br />0.127
<br />0.144
<br />0.163
<br />0.185
<br />0.204
<br />0.223
<br />0.245
<br />0.269
<br />0.293
<br />0.317
<br />0,346
<br />0.377
<br />0.406
<br />0.451
<br />0.490
<br />0.576
<br />0.696
<br />0.864
<br />1.015
<br />1.176
<br />1.325
<br />1 .454
<br />1,505
<br />1.555
<br />1,589
<br />1.632
<br />1.675
<br />1.704
<br />1.738
<br />
<br /> 6-Hour Design Storm -
<br />TIME Cumulative Depth
<br />(MINT 5-vr 1 OO-yr
<br />185 0.922 1.771
<br />190 0,939 1,802
<br />195 0,951 1.826
<br />200 0.965 1.853
<br />205 0.979 1.879
<br />210 0,993 1.906
<br />215 1.006 1.932
<br />220 1.019 1.956
<br />225 1.,029 1.975
<br />230 1.040 1.997
<br />235 1.051 2.018
<br />240 1,063 2.040
<br />245 1,075 2.064
<br />250 1.086 2.086
<br />255 1.097 2.107
<br />260 1.104 2.119
<br />265 1.115 2.141
<br />270 1.126 2.162
<br />275 1.134 2.177
<br />280 1.143 2.194
<br />285 1.150 2.208
<br />290 1.159 2.225
<br />295 1.168 2.242
<br />300 1.176 2.258
<br />305 1.185 2.275
<br />310 1.193 2.290
<br />315 1.200 2.304
<br />320 1.209 2.321
<br />325 1.216 2.335
<br />330 1.224 2.350
<br />335 1.231 2.364
<br />340 1.238 2.376
<br />345 1.243 2.386
<br />350 1.247 2.395
<br />355 1.250 2.400
<br />360 1.250 2.400
<br />
<br />1
<br />
<br />2-Hour Storm Depths based on Douglas County Storm Drainage
<br />Design and Technical Criteria for Basins 10 to 20 square miles for
<br />Zone III
<br />
<br />6-Hour Storm Depths based on USGS storm distribution for 100-year storm
<br />
<br />1-HR STORM EVENT DISTRIBUTION
<br />
<br />2-HR STORM EVENT DISTRIBUTION
<br />
<br />RAINFAll DISTRIBUTION FOR 1-HOUR, 2-HOUR, AND 6-HOUR STORMS
<br />
<br />6-HR STORM EVENT DISTRIBUTION
<br />
|