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<br />TABLE OF CONTENTS <br /> <br />DRAiNAGE CRITERIA MANUAL (V. 1) <br /> <br />12.0 CLEAN WATER ACT SECTION 404 PERMiTTING PROCESS .............,........_...............,_....,PL-26 <br />12,1 Purpose of the 404 Permil..._.......................................................,-..........................,... PL-26 <br />12.2 Activities Requiring Permit. ....... ..... .............. .....,.......... ...... ..,............ ....,....,..... ,...... ...., PL-26 <br />12.3 Who Should Obtain a Permit........_...............,..................................................,...........PL-26 <br />12.4 Definition of Waters of the United States........................,.......................,.................... PL-26 <br />12.5 Pre-Application Meetings .",... .".. ..,....... .". ..". ..".. .". .'".. .",.. .". ..",..,... .".. .,... .". ..",."... PL-27 <br /> <br />13,0 REFERENCES.. ........... ....,............ ...,... ..,................. ..... .........,........... ...... ......... ........... ..........., PL-28 <br /> <br />Rainfall <br /> <br />1.0 OVERViEW...........,.. ..................... ........... ,.....,............. ...................... ...... ......... .... ........,....... ..... RA-l <br /> <br />2.0 RAINFALL DEPTH-DURATiON-FREQUENCY ......................................................................., RA-2 <br />2.1 Rainfall Depth-Duration-Frequency Maps .......................,............................................ RA-2 <br />2,2 Rainfall Depths For Durations Between 1- and 6-Hours ................................,....,........ RA-2 <br /> <br />3.0 DESIGN STORM DISTRIBUTION FOR CUHP..............,..............,..........,................................ RA-3 <br />3.1 Temporal Distribution..............................................,...................................................., RA-3 <br />3.2 Adjustment to Rainfall Distribution for Watershed Size................................,.............., RA-4 <br /> <br />4,0 INTENSITY-DURATION CURVES FOR RATIONAL METHOD ............................._................. RA-6 <br /> <br />5.0 BASIS FOR DESIGN STORM DISTRIBUTION .......................,...........,.................................... RA-7 <br /> <br />6.0 SREADSHEET DESIGN AIDS ............_.......,......................,............,....................,.................... RA-8 <br /> <br />EXAMPLES... .,.. .,. .,.". ..',... ."....... .",... .',.. .."...... .".. .". ..".,.". ."... .". .,."... .,.. .',.,. .,'. ..,.., .". ..,.. .". .,. RA-9 <br />7,1 Example Computation of Point Rainfall....................................................................,... RA-9 <br />7.2 Example Distribution of Point Rainfall .......................................................................... RA-9 <br />7.3 Example Preparation of intensity-Duration-Frequency Curve................,................... RA-lO <br /> <br />8,0 REFERENCES..... ........... .......... .....,..........,..".....,.....,.......................... .......... .....,.........,......... RA-12 <br /> <br />7,0 <br /> <br />Runoff <br /> <br />1.0 OVERViEW.................................,..................................,.............,.....................,..............,.....,.. RO-l <br /> <br />2,0 RATIONAL METHOD. ....,.................,..... _........,..... _....,................... ....,.. ......... ...... ..........,.......... RO-3 <br />2,1 Rational Formula .......................,.....................,....................................,....,...............,..RO-3 <br />2.2 Assumptions .......................... ........... .......... ..,.. ...................... ..,.. .............. .......... .......... RO-4 <br /> <br />2.3 Limitations",.. .".,.',....,.. .,_.. ..",. ...,... .". .,.... .". ..',.,.". ."... .".,. .".. .',.. .".,.','.. .,. ..". .'-" ."... .,. RO-4 <br />2.4 Time of Concentration _................................................................................................_RO-5 <br />2.4,1 Initial Fiow Time........__...,......,.....,...................,.......,....__......................,__........' RO-5 <br />2.4.2 Overland Travel Time ...._.......,.....,.......,..__..............,.........,....__................'....... RO-6 <br />2.4,3 First Design Point Time of Concentration............._.........,.........,..................._.. RO-6 <br />2.4.4 Minimum Time of Concentratlon.._.,................................................................. RO-7 <br />2,4,5 Common Errors in Calculating Time of Concentration ....,........__....__............... RO-7 <br />2.5 Intensity..,.....,...... __........ __.... .....,................... ..,.. .... .................. __........ --.. ..... ....... --,......... RO-7 <br />2.6 Watershed Imperviousness........ ___.............................., .... ......,..... __.... --... __.., ....,.... --.., -, RO-7 <br />2.7 Runoff Coefficient .........,. ...............,..,. .......... ............................ ...................,....,. -.,. ....., RO-8 <br /> <br />COLORADO URBAN HYDROGRAPH PROCEDURE ..,....................,..................._.............,RO-19 <br /> <br />3.1 Background.. .._." .......... _...,......,... _, _............_.....,..........................'.' .....,....,...-,.... ....,... RO-19 <br />3.2 Effective Rainfall for CUHP....,....._.......,.........................,..........,....--...........--, ,..,.....,. RO-19 <br />3,2.1 Pervious-Impervious Areas .......,_._..,....,..__....,.......,_........._.........___......'......... RO-19 <br />3.2.2 Depression Losses ,.....,..........__..........._....,.....,....,......._.........._.'..........,..,.-,.. RO-20 <br /> <br />3.0 <br /> <br />TOC-vi <br />Urban Drainage and Flood Control District <br /> <br />6/2001 <br /> <br />e <br /> <br />e <br /> <br />e <br />