This may look like an ordinary sidewalk planter, but it’s actually part of a strategy to make New Haven greener. Sunk below street level, this “bioswale” diverts rainwater back into the ground instead of into the city’s sewer system. In a project organized by the Urban Resources Initiative at Yale’s School of Forestry and Environmental Studies, the city plans to install more than 275 bioswales downtown and in other parts of the city. Even Harvard approves: the project recently won a green infrastructure award from the Kennedy School of Government.