TECHNICAL DESIGN BRIEF - 9 ERSKINE LANE VIEW ROYAL, BC MULTI FAMILY RESIDENTIAL DEVELOPMENT

TABLE OF CONTENTS

1 INTRODUCTION..................................................................................................................................3 2 SERVICING.........................................................................................................................................3 2.1 Water Servicing (Domestic)........................................................................................................3 2.2 Fire Flow Capacity (Fire Underwriters Survey).......................................................................3 2.3 Sanitary Sewer Servicing.............................................................................................................4 2.4 Rain Water Management Calculations.....................................................................................7 2.4(a) Town of View Royal Rain Water Management Criteria...................................................7 2.4(b) Design Storm...........................................................................................................................8 2.5 Storm Water Management – Onsite.........................................................................................9 2.6 Storm Water Management – Offsite....................................................................................... 11 2.7 Hydro/Tel/Cable/Gas................................................................................................................ 11 2.8 Transportation, Road Access and Egress...............................................................................12 3 CLOSURE..........................................................................................................................................12

APPENDIX

A Site Plan – Figure 1 B Water Network – Figure 2 and FUS Calculations C Offsite Sanitary Sewer – Figure 3 and Sanitary Sewer Capacity Assessment D Stormwater Management – Figure 4

1 INTRODUCTION

This design brief comments on the general servicing proposed for the development of 9 Erskine Lane, located within the Town of View Royal (Legal Description: Lot B, Plan VIP26648). The site area is approximately 2.35 hectares and the developer proposes the creation of a 372-unit residential development comprising four buildings (5 to 6 stories each) as illustrated in Appendix A, Figure 1. The site is bounded to the north by Watkiss Way, to the south by a similar multifamily development and to the east by the Victoria General Hospital. The existing site topography consists of a local high point at the northeast property line of approximately 27m, sloping gently to the southwest corner of the site where the elevation is approximately 14m. The site is split approx. one third/two thirds by the existing CRDIS trunk supply mains. A conceptual site plan, drainage plan, and sanitary sewer plan for the proposed development has been included in the appendices.

2 SERVICING

2.1 Water Servicing (Domestic)

The domestic water meters will be sized according to the American Water Works Association (AWWA) M22 meter sizing guidelines. It is anticipated that each building will require a minimum 50mm diameter domestic service. Service will be provided from the proposed 300mm dia. PVC watermain along Erskine Lane as shown in Appendix B. Proposed service lines will include domestic and fire metering with backflow prevention.

2.2 Fire Flow Capacity (Fire Underwriters Survey)

Fire flow demand shall be in accordance with the current Fire Underwriters Survey (FUS) Water Supply for Public Fire Protection. A brief summary of fire flow requirements has been included in Table 1 below; a detailed preliminary FUS calculation for the proposed development has been included as Appendix B.

Table 1 - Fire Flow Requirements

Based on the preliminary fire flow analysis (FUS), the maximum required fire flow is anticipated to be 266.7 L/sec (Appendix B). It is anticipated that the proposed 300mm PVC watermain along Erskine Lane will meet these requirements. Existing fire hydrants in proximity to the site include hydrant VRFD103, which is 186m from Bldg A and B, 80m from Bldg C and 114m from Bldg D. As this hydrant is located more than 45m from the proposed Siamese connectors, additional hydrants will be required (see Figure 2). The practical pumping limit for a single pump truck is approximately 150 L/sec per hydrant; therefore, one additional hydrant will be required at each site access road (within 45m of each Siamese connection point). Both hydrants would be used simultaneously to reach the required 266.7 L/sec fire flow dictated through FUS analysis.

2.3 Sanitary Sewer Servicing

An existing 200mm diameter PVC sanitary sewer main runs along Erskine Lane fronting the property. This 200mm diameter main represents the northern reach of a larger system which collects sewage from the immediate area before crossing the Trans-Canada Highway, through the back yards of properties along Vickery Road, across Helmcken Road, into Helmcken Park Pump Station as depicted in Figure 3, Appendix C. This system ultimately ties into the CRD Craigflower Pump Station approximately 1.45km southeast of the site.

A Sanitary Master Plan was completed for the Town of View Royal by McElhanney Consulting Services Ltd. (McElhanney), Final Report dated January 2nd, 2019. The report analyzed the sanitary sewer systems adjacent to the proposed development site including the gravity system fronting the site and the downstream pump station and forcemain systems described previously. The assessment included inflow and outflow characteristics based on present and future development conditions. The sanitary design requirements