ice jam

New Boston Fire Chief Dan MacDonald

The freeze-thaw weather cycle of recent weeks is fueling ice jams in rivers across New Hampshire – including in New Boston, where a huge, persistent blockage could cause flooding this spring.

The jam on the Piscataquog River is more than 3,000 feet long – the length of 10 football fields.

New Boston Fire Chief Dan MacDonald says it's made of foot-thick icebergs that have melted and cracked, then frozen back up into a single solid glacier.