Pomona Mills Washout Bank Stabilization Project

Toronto and Region Conservation Authority (TRCA) has undertaken remedial bank stabilization works to protect York Region’s sanitary infrastructure along Pomona Creek, a tributary of the East Don River, in the City of Markham. The main objective of the works was to remediate the failed bank in order to provide underground sanitary infrastructure protection and reduce public safety risks. 

Project Location

The project area is located along a stretch of Pomona Creek, a tributary of the East Don River, northwest of the closet major intersection at John Street and Bayview Avenue. The immediate bank failure is located northeast of the Pomona Valley Tennis Club parking lot, which is found within Pomona Mills Park at 200 John Street, Markham.

Figure 1. Pomona Mills Project Location. Source: TRCA, 2018.
Learn More About This Project

Project Background

In early 2018, the Regional Municipality of York Environmental Services Department advised TRCA of a bank failure near the Region’s Central Collector Sewer in Pomona Mills Park. TRCA’s Erosion Risk Management team immediately initiated hazard monitoring to assess the risk and commenced planning, design and permitting for remedial infrastructure protection and bank stabilization works in March 2018. Remedial works were implemented between November 19th and November 30th, 2018.

Pomona Mills washout in April 2018
Figure 2. Pomona Mills washout in early spring of 2018. Source: TRCA, 2018
Pomona Mills washout in August 2018
Figure 3. Pomona Mills washout with significant vegetation in August 2018. Source: TRCA, 2018.
Scope of Work
  • Development of detailed designs drawings
  • Obtain all necessary permits and approvals to proceed with construction
  • Construction of remedial works

Construction Information

The remedial works were implemented by TRCA between November 19th and November 30th, 2018. The bank stabilization works include a vegetated stone erosion control mat.

Excavator installing a vegetated stone erosion control mat for bank stabilization works in Pomona Mills Park
Figure 4. Construction of bank stabilization works at Pomona Mills Washout. Source: TRCA, 2018.
Public Consultation

Prior to mobilization, Notice of Construction signage was installed within Pomona Mills Park. Construction notices were also delivered to properties in close vicinity to the project area.

Project Updates

Week of June 3, 2019

Vegetation has begun to establish within the bank treatment and the restored areas of the project site. TRCA will continue to monitor the treatment to ensure the bank stabilization is performing as intended.

Figure 5. Vegetation is establishing within the project site. Source: TRCA, 2019.


Week of December 3, 2018

TRCA completed the project on November 30th, 2018. TRCA will continue to monitor the treatment to ensure the bank stabilization is performing as intended.

Restored project area including the regraded washout, installed vegetated stone erosion control mat, sod, tree plantings and restored fence.
Figure 6. Completed bank stabilization and restoration plantings for Pomona Mills Washout Project. Source: TRCA, 2018.
Contact Us:

The Project Planning Team is located at TRCA’s Boyd Field Centre Office in Vaughan:

Restoration and Infrastructure Division, Erosion Risk Management
9755 Canada Company Avenue
Vaughan, Ontario
L4H 0A3

For more information regarding this project, please contact Phil Wolfraim, Project Manager:
Phil Wolfraim, Project Manager