Sentence:  At the mouth of the river there is shoal water, in which the ice grounds, and in severe weather, it forms a point of support for successive floating masses, until it sometimes <WSD>gorges</WSD> up for many miles above the ferry of the railway line. 
Meaning of the word marked with <WSD> tags:  To fill up (an organ, a vein, etc.); to block up or obstruct;  of ice: to choke or fill a channel or passage, causing an obstruction.