Laserfiche WebLink
Targeted Drainage Report— Twentieth Ave Substation WO# 100026553 <br />1.3 DEVELOPED CONDITIONS <br />The proposal is to expand existing Twentieth Ave substation in order replace aging equipment and to maintain <br />and maintain maintenance access. <br />The substation will generally remain as it has in it was described in 1.2 Existing Conditions with the exception of <br />one of the existing metalclad switchgears being replaced with a new one. <br />Temporary erosion and sediment control measures will be implemented during construction in accordance with <br />City stormwater management requirements. All on -site soils disturbed by construction activities will be <br />stabilized with grass and or landscaping prior to the removal of any temporary erosion and sediment control <br />measures <br />Granular fill material will be imported to provide a suitable base for the driveway and station yard area within <br />the station security fence. The station yard and perimeter area outside the security fence will be surfaced with <br />substation rock. A new gate which expands the accessibility to the station from within the Operations Center <br />will be added and paved. <br />Precipitation falling within the station yard will infiltrate through the substation rock. Below the substation rock, <br />stormwater will be temporarily stored within the voids of the crushed surfacing base course (CSBC) while it <br />slowly infiltrates into the native soil. <br />A french drain will be installed at the foot of the graded slope to collect, retain, infiltrate, and convey runoff <br />generated from the graded slope west of the substation. <br />Page 4 <br />