The River Šuica (or Šujica) is a sinking river flowing through Duvanjsko Polje and the wider region of Tropolje in Bosnia and Herzegovina. Its sources are Mali Stržanj and Veliki Stržanj, both close to village of Stržanj. It flows through and draines most of its waters from Kupreško Polje, the Šuica Valley and Duvanjsko Polje. The river disappears underground in large Kovači estavelle, eponymous of nearby village Kovači, in southwestern corner of Duvanjsko Polje. Waters of the Šuica than partially re-emerges at the source of Ričina in village Prisoje, which than empties into the reservoir of Buško Blato after a short flow of cca 0-50 meters, depending on water levels of in resservoir.