Dan,
Jeya reviewed and requested that DCR should be notified since it is DCR jurisdiction.

Thank you for reporting this issue to the City of Cambridge. Unfortunately, the City is not responsible for addressing issues on state property, but we've shared this report with the Massachusetts Dept. of Conservation & Recreation (DCR) and asked them to address. Please contact DCR Community Relations at 617-626-4973 for direct follow-up about this.