While mayors throughout North America were scurrying last week to meet Amazon’s deadline for applications to host the online retailer’s second headquarters, in Toronto another big American tech company, Google’s parent Alphabet, was already proceeding with an ambitious plan to redevelop the city’s waterfront on Lake Ontario. Last Tuesday, the government agency Waterfront Toronto and Sidewalk Labs, a division of Alphabet, announced a $50 million project called Quayside to develop a nearly 5-hectare parcel on Lake Ontario. Sidewalk Labs executives and Toronto officials aim to demonstrate how Silicon Valley know-how can address chronic urban problems. “We believe that by leveraging technology and combining it with really smart, people-centric urban planning, we could have really dramatic impacts on quality of life,” said Daniel Doctoroff, the chief executive of Sidewalk Labs who was deputy mayor of New York City under Mayor Michael Bloomberg. “But you need to do it in a place – ideally a place large enough to be a laboratory for an integrated approach to innovation and planning.” The Toronto waterfront project ticks off all the boxes related to sustainability and cutting-edge technology. Carbon-neutral thermal energy would heat the development. Machines would separate trash from recyclable waste. Buildings would be modular so they can convert from residential to commercial space as needed. Sensors on street lamps and other fixtures would turn lights on and off, monitor air quality and provide guidance to autonomous vehicles. And heaters under sidewalks and bike paths would melt the snow in the winter. But experts warned that Toronto officials will need to oversee the project closely. Tech companies have failed to pursue smart design in Northern California, where their headquarters in San Francisco and San Jose have caused rents to skyrocket and where their sprawling suburban facilities are often exemplars of bad land use. The project also raises concerns about how Sidewalk Labs will use the data it collects with all its sensors. By John Dyer