New London and Norwich each will receive multimillion-dollar grants to boost downtown development projects through a $45 million Connecticut Communities Challenge Grant program announced by Gov. Ned Lamont on Wednesday. New London will receive $5.9 million to help renovate several buildings on State, Bank, Water and South Water streets, and Norwich will receive $2 million to assist a Baltic construction company to revitalize the derelict former YMCA property at a prominent Main Street gateway. Mattern submitted the lone bid to the city of Norwich for the YMCA property. The $2 million grant will contribute to the company’s plans to do a partial demolition and partial renovation to relocate the construction company’s headquarters on the property. Accompanying commercial space could be marketed for a brew pub, restaurant and/or coffee shop. The $5,985,460 coming to New London will fund a mix of public and private projects, including downtown lighting, sidewalk and traffic signal improvements and rehabilitation of murals on downtown buildings. It also will fund a new home for the city’s shuttle service.