Laserfiche WebLink
Technical Information Report July 2015 <br /> Everett Public Storage <br /> 4.1 Flow Control Analysis <br /> As required by the City of Everett's 2010 Stormwater Management Manual, hydrologic modeling of <br /> the proposed site runoff and flow control facilities have been completed using the WWHM <br /> software. The following details the modeling parameters used and the results of the hydrologic <br /> model verifying that the proposed flow control facilities described in Section 4.0 are adequate for <br /> meeting the required standard. Stormwater discharges from the new and replaced impervious <br /> areas are required to match developed site discharge durations to pre-developed durations for the <br /> range of pre-developed discharge rates from 50% of the 2-year peak flow up to the full 50-year <br /> peak flow. The pre-developed condition has been assumed as a forested land cover condition. <br /> WWHM Precipitation Factor= EVERETT 1.0 <br /> Existing Conditions: Till Forest = 2.50 Ac. <br /> Developed Conditions: Impervious Area = 2.13 Ac. (85% impervious) <br /> Till Grass =0.37 Ac. (landscape) <br /> The vault will have an internal footprint of 6,200 square feet providing a 10% factor of safety in the <br /> vault design. The WWHM model output has been included herein, verifying that the required <br /> standard is met. <br /> 14114 Everett Storage TIR Revised 0715.doc 13 AAM <br />