originating in Iran allow the Tigris's flow to increase, and it maintains a steady course thereafter. The three marshes once provided an intertwined environment, particularly during periods of flooding as the rivers overflowed. Central The Central Marshes receive water from influxes of the Tigris's distributaries, namely the Shatt al-Muminah and Majar al-Kabir south of Amarah. The Tigris serves as the marshes' eastern boundary while the Euphrates serves as its southern boundary. Covering an area of , the marshes consist of reed beds and several permanent lakes including Umm al Binni lake. The Al-Zikri and Hawr Umm Al-Binni lakes are two of the notable lakes and are deep. Hammar The Hammar Marshes are primarily fed by the Euphrates and lie south of it with a western extent to Nasiriyah, eastern border of the Shatt al-Arab and southern extent of Basrah. Normally, the marshes are a area of permanent marsh and lake but during period of flooding can extend to . In periods of flooding, water from the Central Marsh, fed by the Tigris can overflow and supply the marshes with water. Hammar Lake is the largest water body within the marsh and has an area of by , with depths ranging between -. In the summer, large portion of the marshes' and lake's shore are exposed, revealing islands that are used for agriculture. Hawizeh The Hawizeh Marshes lie east of the Tigris and a portion lie in Iran. The Iranian side of the marshes, known as Hawr Al-Azim, is fed by the Karkheh River, while the Tigris distributaries Al-Musharrah and Al-Kahla supply the Iraqi side, only with much less water than the Karkheh. During spring flooding, the Tigris may directly flow into the marshes. The marshes are drained by the Al-Kassarah. This river plays a critical role in maintaining the Al-Hawizeh marshes as a flow-through system and preventing it from becoming a closed saline basin. The marshes are from north to south and about from east to west, covering a total area of . Permanent portions of the marshes include the northern and central portion while the southern part is generally seasonal. Moderately dense vegetation can be found in the permanent areas along with large -deep lakes in the northern portions. As the Hawizeh Marshes fared the best during the draining, they can facilitate the reproduction of flora, fauna and other species in Central and Hammar marshes. Ecology The marshes constitute