001-40 WC 143 JULY-AUG25 PT - Flipbook - Page 19
Black and Veatch, Wikimedia
idea is to contain excess rain, snow and greywater, which mixes
with sewage in the city’s combined sewers, and then convey it
in controlled, manageable volumes by gravity to the Ashbridges
Bay Wastewater Treatment Plant for eventual, safe dispatch into
Lake Ontario.
But the Coxwell Bypass is just the beginning. Construction
of a 27-hectare landform next to Ashbridges Bay started in
2019 and it, too, is nearly completed. Built using shale and
rock excavated during the tunnel’s construction, the landform
is integral in that it will accommodate a new high-rate wet
weather flow treatment plant. A new pumping station and
ultra-violet disinfection facility at Ashbridges Bay, meanwhile,
are about one-third built, and two more tunnels are planned
to complement the Coxwell bypass. Detailed design work for
the six-kilometre Inner Harbour tunnel is underway and, with
several interconnects into the harbour, is expected to begin in
2029. Then, the City will start designing the Taylor-Massey
Creek tunnel. All told, the three tunnels will be integrated,
span 22 kilometres alongside the three waterways, and feature
a supporting cast of seven storage tanks, 12 storage shafts, 27
sewer connection points, a real-time control system to regulate
flows, and an outfall directing treated wastewater 3.5 kilometres
out into Lake Ontario.
WAT E R C A N A D A . N E T
DON RIVER AND CENTRAL WATERFRONT WET
WEATHER FLOW SYSTEM (DR&CW WWF System):
$3.7 billion
Location: Toronto
Owner: City of Toronto
Funding: Public
Substantial Completion: 2038
• Coxwell bypass (stage 1): Black & Veatch Canada
in association with R.V. Anderson Associates Limited
(consultants); North Tunnel Constructors (contractor).
• Inner Harbour West Tunnel: Hatch/AECOM
(consultant)
• Mid Toronto-Interceptor (MTI) Real-Time Control: Tetra Tech (consultant)
• Integrated Pumping Station (IPS) Black & Veatch
Canada in association with R.V. Anderson Associates
Ltd. (consultants); Strabag Canada (contractor —
contract 2)
• Ashbridges Bay Landform Project: Toronto and
Region Conservation Authority (TRCA) with Shoreplan
Engineering (designer); TRCA (constructor of landform)
• UV (Ultraviolet) Disinfection Facility: AECOM
(consultants); Graham (contractor)
• Outfall: Hatch, Jacobs and Baird (consultants);
(SAJV) Southland Astaldi Joint Venture (contractor)
Other Key Players: Wood (WSP) (environmental
engineer/geotechnical studies);
Golder (WSP) (geotechnical services); Arcadis-IBI
Group (risk assessment); LEA Consulting (engineer-planning); R.V. Anderson Associates Ltd.; E.S. Fox;
Arup (engineer); KSB PUMPS INC (product supplier)
Legal: Strikeman Elliott LLP (advisor)
The Don River and
Central Waterfront
Wet Weather Flow
System program is
particularly driven by
the realization that
the city is densifying
downtown, close to
the lake and the Don.
WATER C AN ADA • JULY/AUGUS T 2025
19
