The Gharraf Canal, Shaṭṭ al-Ḥayy (Arabic: شط الحي), also known as Shaṭṭ al-Gharrāf (Arabic: شط الغرّاف) or the Hai river, is an ancient canal that connects Tigris with Euphrates in Iraq. As an Ottoman defensive line lay along the canal, it was a theater to intense military action during the First World War; e.g. the siege of Kut. Between 1934 and 1939, the Kut Barrage was constructed in the Tigris to control the water level of the river and to provide a constant inflow of water to the Shatt al-Hayy.