On my first helicopter flight in Afghanistan, I saw lines of “craters” running across the landscape seemingly everywhere. I had no idea what they were. They were systematic and obviously manmade. They couldn’t have been bomb craters or exploded improvised explosive devices, I thought.
My guess was they had something to do with irrigation. I have come to find out that these “craters” are actually kariz shafts that form part of an ancient and extremely complex water management system that supplies water for every purpose in many areas of Afghanistan.
Very similar to the Balinese Water Temples I have previously discussed, the kariz define the cultural identity and structures of villages and towns, so are much more than mere irrigation systems. In many places, these are called qanat systems and they originated in Persia (now Iran) over 3,500 years ago. Some of these systems have been operating for over 2,000 years and today supply all the water to many areas of the Middle East and North Africa, including large cities.
The kariz consiste of a series of vertical shafts or wells, if you will, connected by underground horizontal shafts linking the vertical wells. At some point, the water flowing through these underground canals comes out at the surface downstream into surface canals for use as drinking water, irrigation, and other purposes. Kariz systems are even used for air conditioning and ice production and storage.
These systems are extremely complex and require an understanding of water tables and where water may be found underground upslope of the target village or town. The horizontal shafts must be dug at a precise downward angle so water does not flow too quickly or slowly. If too fast, the channel erodes and the system collaspes. If too slowly, water won’t flow at all.
These water hydraulic systems have been described as the single most important Persian (Iranian) contribution to hydraulic science and they developed this technology in antiquity.
Modern development workers and agricultural scientists in Afghanistan I ran into had absolutely no appreciation of the wonders of this ancient technology and many had never heard of it. I spoke with one State Department person who told me that one of the agricultural priorities was a holding dam in Ghazni Province to temporarily collect spring runoff for later use in surface canals for irrigation. My question to him was, why not repair kariz systems that are permanent and far more efficient. He had no response.
There are three primary advantages of kariz systems over dams. One is that water flowing underground is not subject to the intense evaporation issues that surface water is. Another is that the water remains pure at least until it is brought to the surface into shorter canals. One of the cultural aspects of the kariz system is that wealthier people live closer to the output of the kariz, thus having purer water and more of it for irrigation.
Water quality and amount deteriorates as the surface canals move water farther downstream. Third, while kariz certainly require
maintenance, there are specialists in place who build and maintain them. Machinery is not required, although it is certainly possible that some machinery could make certain tasks easier, such as digging. But, the kariz does not require it. Dams all require complex machinery and canal maintenance that Afghanis do not have and, if given to them, they cannot properly maintain. Long open canals require much more maintenance than canals associated with the kariz system.
So, with American agricultural and other development experts, it is likely that the kariz systems will be ignored or replaced with systems that are harder to maintain and will inevitably fail. I can only hope that the indigenous knowledge assiciated with kariz building and maintenance will not be lost. When the development experts are gone and the dam infrastructures fall apart, the karizes will hopefully remain.
Much like the Balinese Water Temple water management systems, the kariz systems are an integral cultural part of Afghan life in many places. Specialists exist to build and maintain them and, traditionally, all work is done by hand. Normally, kariz are commissioned and owned by wealthy individuals and rulers who can afford the expense. They own them and control the water rights and a complex series of laws have originated to take care of these issues in communities. Those kariz that have been supplying water for centuries have laws that have been governing the water use all that time.
The kariz, or qanat, system of water supply and management is perhaps still be best option for arid and semi-arid conditions. I will do a future post that provides more details of kariz construction. It truly is amazing. And the western agricultural and water management “experts” must take them into consideration before they recommend expensive and unmaintainable alternatives as they always do.