Three small rivers flow through Kärdla: Nuutri River, Liivaoja and Kammioja, as well as innumerable ditches, streams and streamlets. These waterways are bridged with small bridges called trumms ("drums"). The word trumm is borrowed from the Estonian Swedish language (trumma) and it was used everywhere in Hiiumaa for a bridge that could be crossed with a carriage. Today, the word trumm is used for bridges only in Kärdla and all the trumms have names.