Wiktionary
vb. (context intransitive English) To become filled or clogged with silt.
WordNet
v. become chocked with silt; "The river silted up" [syn: silt]
Usage examples of "silt up".
Had some valve given way in my unconscious, releasing a river of libido that cut big chunks of miscellanea from the banks it rushed between, to deposit them in shiny layers of silt up front here where I normally take my ease?
What good will it do to stop these mysterious magical murderers, if it allows common thieves to run amok, or we let the walls fall into ruin, or the harbor silt up so that no ships can dock?
And some branches of the delta silt up, others are redirected to the river by artificial channels, still others are allowed to flow, because it is impossible to restrain everything and it is better for the river to lose a part of its water and still maintain its course, if it wants to have a recognizable course.
The two slipways were left to rot, two tidal docks were allowed to silt up.