City staff together with Toronto and Region Conservation Authority (TRCA) have initiated a Flood Remediation Study of Highland Creek (Markham Branch) to evaluate the options for flood remediation measures that eliminate the risk of flooding within the study area (see Figure 1). The study follows the direction of Council which approved the redevelopment of the lands at the southeast corner of Corporate Drive and Consilium Place with four residential buildings, ranging in height from 36 to 45 storeys and containing 1,515 dwelling units. Council approval was subject to a Holding (H) provision in the Zoning By-law which would not be removed until issues related to floodplain and stormwater management have been resolved.

 

Study area of the Highland Creek (Markham Branch) Flood Remediation Study.

Study area of the Highland Creek (Markham Branch) Flood Remediation Study

View of the Highland Creek (Markham Branch) Bounded on the west by McCowan Road, Highway 401 to the north, Markham road to the east and Ellesmere Road to the south

View of the Highland Creek (Markham Branch) bounded on the west by McCowan Road, Highway 401 to the north, Markham road to the east and Ellesmere Road to the south

Project Goals

  • To characterize existing flood risks from riverine flooding and identify causes/mechanism of flooding;
  • To develop appropriate flood remediation measures that eliminate the risk of flooding within the Study Area and unlock the potential for redevelopment opportunities;
  • To identify design considerations, constraints to implementation, and approximate costs to minimize uncertainty for future design phases in terms of design and constructability; and
  • To identify mitigation measures required as a result of implementing flood remediation.

Study Overview

The Study is being undertaken in 2 stages. Stage 1 involves a Technical (Feasibility) Study and Stage 2  involves a Municipal Class Environmental Assessment. The Project Team have hired the consulting firm Morrison Hershfield to undertake the study.

view of Highland Creek at Corporate Drive
Corporate Dr. – Upstream Face
view of Highland Creek at Bellamy Road North
Progress Av.  – Downstream Face
view of Highland Creek at Progress Avenue.
Bellamy Rd. North – Downstream Face
 

Project Schedule & Phasing

Anticipated project duration June 2019 – April 2021

Stage 1 Technical (Feasibility) Study

Phase 1: Project Problem/Opportunities and Constraints

  • Background Review and Gap Analysis
  • Fluvial Geomorphic Assessment
  • Hydraulic Modelling
  • Erosion Threshold Assessment

Phase 2: Screening of Initial High Level Alternative Solutions

  • Identify alternative solutions that can provide Flood Protection to meet the Project Objectives
  • Protection, Screen to meet Project Objectives

Phase 3 – Development and Evaluation of Refined Alternative Solutions

  • Hydraulic Validation of Refined Alternative Solutions
  • Geotechnical and Foundation Investigation Including Borehole Sampling and Analysis
  • Identification and Mitigation of Impacts to the Creek
  • Evaluate Refined Alternative Solutions and Identify Feasible Solutions
  • Technical Report

Stage 2 Class Environmental Assessment

The commencement of the Class EA is subject to the recommendations and outcome of the Technical (Feasibility) Study.

View the Municipal Class EA Planning and Design Process.

Additional information will be provided at a future date.

Information and Reports

On June 22, 2010, Scarborough Community Council received a Report from City Planning Staff regarding development on the southeast corner of Consilium Place and Corporate Drive.