OE


The speaker cannot be watching his town wash away from an estuary (A) or river, or he would have washed away as well. Neither can he be watching from a ravine (B), as being in a narrow steep-walled canyon would not place him above the town or afford him a vista. He could, however, watch the town below being swept away from a butte (C) or hill rising abruptly from the surrounding, flat landscape.

The barriers did not countenance ( E ), meaning placate or pacify as this would make no sense in the context of the sentence. Neither did they assuage ( F ) or soothe the flood waters. The makeshift barriers obviously gave in or capitulated (D) to the rising flood waters.
Neither calumny (G) nor aspersion (H) make sense in the context of the sentence. Both refer to verbal attacks meant to destroy reputations or friendships (calumny) or disparaging remarks (aspersions) that cast doubt. Aspersion, furthermore, is almost invariably used in the plural with the word "cast" as in "cast aspersions." The town washed away like so much debris or detritus (J), for it is indeed the detritus that gets sucked down the drain.