217133 - Civil Engineering Ricer Road Stormwater Management Plan

A Feasibility Application Request (FAR) was submitted to Indigenous Services Canada (ISC) in March 2023 to develop a storm water management plan as an added scope to an existing ISC funded project which is at the detailed design phase.
The FAR proposes to determine the most appropriate method of storm water management for the River Road area. Currently the storm sewer flows from this area and is impeded by a dyke which is built along the Cowichan River. The stormwater pools in several areas during high rain events, then eventually discharges either through storm sewer outlets with control gates or through ground percolation. Water pools in low lying areas near the dyke and the feasibility study seeks to find options for transport and disposal of the stormwater pooling around the dyke structure.
The deliverables include, but are not limited to:

1. Project Start up – The successful proponent will meet with the Cowichan Tribes project lead to review the proposed feasibility study tasks and deliverables. Additional items to be discussed will include:
   1. A history of the project area including previous flooding events and drainage issues.
   2. Any protocol and processes for accessing Cowichan Tribes Reserve Lands.
   3. Overview of any future plans for development in the project area.
   4. Project Schedule.
2. Document Review and Compilation - The successful proponent will request all pertinent documents from the Province, Local Municipalities, Indigenous Services Canada (ISC) and Cowichan Tribes and will review all relevant information to the Feasibility Study. This includes and is not limited to:
   1. Existing infrastructure record drawings
   2. Previous Reports or Studies
   3. Aerial Imagery
   4. Land Use Plans
   5. Topographic Maps
   6. LiDAR
3. Site Review and Existing Systems Plan – The successful proponent will review the site areas prior to preparing the existing systems plan. This review will include:
   1. A site visit to determine the accuracy of the LiDAR data
   2. Compiled as-built drawings
   3. Review of the local drainage courses, ditches and road run-off surrounding the project area
   4. Problem areas identified by Cowichan Tribes

• A site plan of the project area including existing systems and topography
• Minor Flow catchment area map
• Major Flow catchment area map

4. Storm Sewer Catchment Area and Minor Flow Calculations – Proposed Drainage Analysis

1. Delineating the individual watersheds and sub catchments within each area
2. Establishing the physical parameters of the sub-catchments and its drainage system
3. Collate the data for input into the model
4. Select the appropriate design storm type, duration and frequency
5. Evaluate and verify the model results.

• A map showing the minor and major flow paths of the modelled watersheds
• A Storm Water Management Model of the catchment areas and the proposed conduits required to convey water along River Road. Meta Data information file shall be included with this deliverable.

5. Option Analysis for stormwater management solutions for the Minor Flows

1. Capital Costs – Class D
2. O&M Costs – Class D
3. Life-cycle Costs
4. Non-monetary Costs

• A recommendation for the best option to be utilized for the project area that should include the pro’s and con’s of each option analyzed, impacts that each option will have on the existing and future development within the project area and what is needed for flood protection for each option identified.

6. Major Flow Hazard Assessment and Major and Minor Flood Construction Levels