51effective way to meet their water needs at a time when alternative sources of water
for drinking and agricultural purposes were not readily available (Oweis et al.
2001 ).
Historically, many settlements have been situated in arid and semiarid climates,
such as the Middle East, Northern Africa and Western Asia. These cultures largely
depended on subsistence farming with few other opportunities to generate income.
Water harvesting became widespread in many of these regions and, although vari-
ous methods were devised almost universally, each emerging culture established
their own unique way of collecting or diverting runoff for productive purposes
(Prinz 1996 ; Oweis et al. 2001 ; Oweis et al. 2012 ).
Many communities in arid and semiarid regions have been harvesting water for
almost as long as humans have engaged in agriculture (Bruins et al. 1986 ). Examples
of water harvesting structures are known from Babylonians, Israel, Tunisia, China
and the Americas (Frasier 1980 ; Boers and Ben-Asher 1982 ; Li 2005 ; Ouessar et al.
2004 ). Such structures have received renewed attention with the implementation of
policies to increase food production since the droughts and food crisis in sub-
Saharan Africa in the 1970s and 1980s (Critchley et al. 1992 ; Prinz and Singh 2000 ;
Denison and Wotshela 2012 ).
The Middle East was one of the first regions in the world to practice harvesting
water for consumption in both domestic and agricultural realms. WH structures
found in this part of the world date back more than 9000 years to Southern
Mesopotamia where simple WH structures were used as early as 4500 BC (Prinz
1996 ; Oweis et al. 2012 ). In the Negev Desert region, now modern day Israel, runoff
irrigation farming has been practiced since the 10th century BC. This form of WH
was used throughout Roman rule and well into the Byzantine era. In North Yemen,
a system dating back to at least 1000 BC diverted enough floodwater to irrigate 20
000 ha of agricultural crops that may have fed as many as 300 000 people. This
method of floodwater management is still in use today, making this region one of
the few places where runoff agriculture has been continuously practiced since the
earliest settlement (Prinz 1996 ; Oweis et al. 2001 ). Similarly, floodwater systems
have been used in regions of modern-day Pakistan and Saudi Arabia, both varying
the design and process to meet the needs of their climate and terrain.
Africa, Northern Africa in particular, has a long history of WH, where the tech-
nique was often devised to match the terrain of each region. Historically known as
the granary of the Roman Empire, in Libya, runoff irrigation was often used to grow
barley, wheat, olive, grapes, figs and dates in this arid region of the continent. This
form of WH also allowed for sheep, pig and cattle farming. The farming system
lasted for over 400 years and sustained a large stationary population, often wealthy,
which created enough crops to generate a surplus (Prinz 1996 ).
Many other WH methods employed in Northern Africa are still used today
including rainwater storage ponds called ʻlacs collinairesʼ in Algeria, Meskat and
Mgoud harvesting systems in Tunisia, Caag and Gawan systems in Somalia, and the
Zay system in Burkina Faso. To the east, in Tanzania, water harvesting has been a
mainstay with rural farmers using rainwater harvesting to irrigate their crops for
centuries. People who rely completely on rainwater for their survival have, over the
Water Harvesting in Dry Environments