The phrase "become dammed" can have various synonyms depending on the context. If we are talking about water or rivers, "become dammed" can be substituted with "blocked," "obstructed," or "dammed up." However, if the context shifts to emotions or energy, "become dammed" can be replaced with "restrained," "suppressed," or "bottled up." Another alternative can be "held back," "curtailed," or "restricted." In summary, choosing the appropriate synonym for "become dammed" will depend on the context and the message the writer or speaker is trying to convey.