FLOOD00281

• County: Larimer
• Community: Greeley
• Title: Design Criteria and Construction Specifications volume 2 of 5 Storm Drainage Criteria
• Date: 10/1/1997
• Prepared For: Greeley
• Prepared By: Department of Public Works
• Floodplain - Doc Type: Educational/Technical/Reference Information

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STORM DRAINAGE DESIGN AND TECHNICAL CRITERIA TABLE 3-2
INTENSITY-DURA TION-FREQUENCY TABULATION
DURATION: 5MIN 10MIN 15MIN 30MIN 60MIN 120 MIN 180MIN
FACTOR: 0.29 0.45 0.57 0.79 1.00
2-YEAR
l-HR DEPTH (IN): 1.04 1.04 1.04 1.04 1.04
DEPTH AT DURATION (IN): 0.30 0.47 0.59 0.82 1.04 1.16 1.25
INTENSITY (INIHR): 3.62 2.81 2.37 1.64 1.04 0.58 0.42
5- YEAR
l-HR DEPTH (IN): 1.49 1.49 1.49 1.49 1.49
DEPTH AT DURATION (IN): 0.43 0.67 0.85 1.18 1.49 1.60 1.69
INTENSITY (INIHR): 5.19 4.02 3.40 2.35 1.49 0.80 0.56
10- YEAR
l-HR DEPTH (IN): 1.76 1.76 1.76 1.76 1.76
DEPTH AT DURATION (IN): 0.51 0.79 1.00 1.39 1.76 1.91 2.02
INTENSITY (INIHR): 6.12 4.75 4.01 2.78 1.76 0.96 0.67
50-YEAR
l-HR DEPTH (IN): 2.51 2.51 2.51 2.51 2.51
DEPTH AT DURATION (IN): 0.73 1.13 1.43 1.98 2.51 2.65 2.75
INTENSITY (INIHR): 8.73 6.78 5.72 3.97 2.51 1.33 0.92
100- YEAR
l-HR DEPTH (IN): 2.78 2.78 2.78 2.78 2.78
DEPTH AT DURATION (IN): 0.81 1.25 1.58 2.20 2.78 2.99 3.15
INTENSITY (INIHR): 9.67 7.51 6.34 4.39 2.78 1.50 1.05
NOTE: DEPTH AT EACH DURATION = l-HOUR OF RAINFALL DEPTH X RESPECTIVE DURATION FACTOR
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DATE: 11/21/94 REFERENCE: MILLER, J.F., AND TRACEY, R.J.
REV: PRECIPITATION-FREQUENCY ANALYSIS OF THE WESTERN
UNITED STATES
. ATL III-GOl J.W.