[custom_adv] The Zayandeh starts in the Zard-Kuh subrange of the Zagros Mountains in Chaharmahal and Bakhtiari Province. It flows 400 kilometres (249 mi) eastward before ending in the Gavkhouni swamp, a seasonal salt lake, southeast of Isfahan city. [custom_adv] The Zayandeh used to have significant flow all year long, unlike many of rivers which are seasonal, but today runs dry due to water extraction before reaching the city of Esfahan. [custom_adv] In the early 2010s, the lower reaches of the river dried out completely after several years of seasonal dry-outs. The Zayandeh River basin has an area of 41,500 square kilometres (16,000 sq mi), altitude from 3,974 metres (13,038 ft) to 1,466 metres (4,810 ft), an average rain fall of 130 millimetres (5 in) and a monthly average temperature of 3 °C (37 °F) to 29 °C (84 °F). [custom_adv] There are 2,700 square kilometres (1,000 sq mi) of irrigated land in the Zayandeh River basin, with water derived from the nine main hydraulic units of the Zayandeh River, wells, qanat and springs in lateral valleys. [custom_adv] Zayandeh River water gave life to the people of central mainly in Isfahan and Yazd provinces. Before the drying-out, water diverted per person was 240 litre. [custom_adv] People have lived on the banks of Zayandeh River for thousands of years. The earliest evidence of human occupation along the River is found in a cave site called Qaleh Bozi near Dizicheh at SW of Isfahan. [custom_adv] More than 40,000 years ago, groups of Paleolithic hunters (Neanderthals) used Qaleh Bozi caves as shelter for seasonal or temporary occupations and left their stone tools and bones of hunted animals. [custom_adv] An ancient prehistoric culture, the Zayandeh River Civilization, flourished along the banks of the Zayandeh in the 6th Millennium BC. [custom_adv] Zayandeh River crosses the city of Isfahan, a major cultural and economic center. In the 17th century, Shaikh Bahai (an influential scholar and adviser to the Safavid dynasty), designed and built a system of canals (maadi), to distribute Zayandeh water to Isfahan's suburbs. [custom_adv] Water from the Zayandeh River helped the growth of the population and the economy, helped established Isfahan as an influential center, and gave a green landscape to Isfahan, a city in the middle of a desert. [custom_adv] The Zayandeh river bed is spanned by many historical Safavid era bridges, and the river used to flow through many parks. [custom_adv] Arthur Pope (an American archaeologist and historian of Persian art) and his wife Phyllis Ackerman are buried in a small tomb in pleasant surroundings in its banks. Richard Frye (an American scholar and Central Asian Studies) has also requested to be buried there. [custom_adv] Water discharge is increased during Persian New Year to allow the river to flow through Esfahan once more during the public holiday.
