City officials have launched Toronto's largest and most significant storm water management program — the Don River and Central Waterfront and Connected Project — which will halt the flow of sewage into Lake Ontario and clean up waterways. The first phase of the five-phase project — the Coxwell Bypass Tunnel — will see a 10.5 kilometre long and 6.3 metre wide tunnel built at a cost of $400 million. The overall project is expected to cost $3 billion.