HALLOWELL — The proposed re-use of the Stevens School complex – a multi-million dollar, multi-year project – is now in the hands of city planners. The master plan for the Stevens School property at the top of Winthrop Street in Hallowell lays out a proposal that if completed, would be the biggest redevelopment project in city history. Owner and developer Matt Morrill submitted his vision for the campus, which is now known as Stevens Commons, to the city Sept.