Environmental Engineering Reference
demand escalated, aggravating regional power outages, a
renewed in the Himalayan, Andean and Southeast Asian regions. In this wave of
projects, estimated hydropower bene
race to the top
ts outweighed irrigation, leading to debates
once again about run of river versus multipurpose storage projects (Siddiqi and
Wescoat 2013 ). The International Hydropower Association is currently developing
a streamlined assessment project.
3.3 The Groundwater Irrigation Power Nexus
One of the reasons for continuing emphasis on surface water storage projects
arguably stemmed from the almost worldwide failure in modern times to manage
groundwater resources. From antiquity, shallow groundwater lifts were likely the
most pervasive means of domestic water and local food supply. This was certainly
the case in semi-arid plains environments prior to large-scale colonial canal irri-
flow and in some cases generated
hydropower for milling and transportation. A monumental example of successful
gravity-fed groundwater development involved qanats (aka qarez, foggara, a
irrigation employed gravity
emanating from Persia and found from the Americas to China. 5 They involved
intensive control of piedmont groundwater aquifers, tapped by drilling ' mother
, avoiding well interference, managing time-based water shares, as well as
maintaining subterranean channels over the course of centuries.
Groundwater pumping technologies changed these early patterns of groundwater
dramatically from the 1950s onwards with the development of increasingly deep
pumping technologies. Cities drew upon water supplies with more consistent
temperature and water quality conditions. But it was groundwater pumping for
irrigation with tubewell and centre pivot irrigation systems that vastly increased
irrigated areas including those with variable terrain (Green 1981 ).
Groundwater appealed to farmers for their more precise individual control over
the timing and quantities of irrigation supply. Naturally, some farmers could afford
individual pump sets while others could not, which gave the former additional
markets, generally monopolistic, over their less prosperous and more dependent
neighbours. Other farmers joined together to co-purchase movable pump sets, while
still others set themselves up in the business of pump rental services.
As groundwater pumping expanded, so too did food production, but at a cost and
in unsustainable patterns. Well interference was an early concern. In places where it
was obvious which well dewatered its neighbour, it became a source of litigation,
remedy and progressive development of groundwater law. In other areas, ground-
water drilling cut through saline aquifers that leaked into fresh ones, diminishing
In other areas groundwater
injection contaminated supplies for
domestic and irrigation use.
For more information see http://en.wikipedia.org/wiki/Qanat .