|Wadi Al Ain, Yemen|
Spate irrigation has a long history. Several sources assume that in Yemen spate irrigation started when the wet climate of the Neolithic gave way to more arid circumstances and that spate irrigation thus has been in use for five thousand years. Similarly, archeologists have discovered the remains of checkdams for spate rivers in Tauran, Iran and Balochistan, Pakistan. In Yemen spate irrigation witnessed its zenith during the Shebean period in the first millenium BC. The great Mar’ib Dam, constructed on Wadi Dhana, irrigated two oases on either banks, estimated to cover 9600 ha.
One can only speculate how the technique spread across the world. The intense development of trade after the Islamic period may have helped spread innovations from the Yemen area. The recent development of spate irrigation in Eritrea is for instance traced back to the arrival of Yemeni migrants 80-100 years ago. Yet it is likely that spate irrigation techmology has sprung up independently in several areas – particularly as it is found in areas as diverse and remote as West Africa, Arabia, Central Asia and Latin America.