The Ma'rib Dam of Yemen

The kingdon of Saba was known to the Hebrews as Sheba, and is the origin of the Biblical Queen of Sheba, who visited Solomon in Jerusalem.  Saba was located in present day Yemen, and had as its capital the ancient city of Marib or Ma'rib.  Marib is near the wide shallow Wadi Dhana, which is a seasonal river.  For most of the year the wadi would be bone dry, but seasonal rains and flash floods from nearby mountains would sometimes turn the wadi into a strong river.  About 750 BC the Sabaeans built a dam across the wadi to form a lake behind the dam, which was one of the wonders of the ancient world.  Water was let out to irrigate about 35 square miles, forming an agricultural paradise.

Map of the Wadi Dhana and the Marib dam and sluice gates, from Ueli Brunner's book, Yemen:  A German Gem

 Marib was the terminus of a caravan route in the ancient world, by which the much sought after incense resins francincense and myrrr were transported to markets around the Meditteranian.  Taxes on the caravan merchants made Marib a rich city, until other trade routes were developed in Roman times .

Photo of the wadi and stone sluice gate, with earthen dam washed away, from Nabatea.net. 

The first version of the dam was a 4 meter high earthen dam, 580 meters long, with a sluice gate at one end.  In 500 BC because of filling with silt the dam was raised to 7 m, the earthen dam was faced with stone, and a sluice gate at the other end was added. 

In 115 BC the dam was raised to 14 m, and the sluice gates were rebuilt in masonry and stone, with extensive distribution channels, settling ponds, andstone spillway channels.   In  450 and 542 AD the dam was  breached and rebuilt.  In 575 AD  the dam was breached and never rebuilt, as Marib was abandoned by then.

Information from:

The Hydraulics of  Open Channel Flow, Hubert Chanson

Nabatea.net

Review of Ueli Brunner's book, Yemen: A German Gem