Ancient aqueducts receive cleaning
January 5, 2013
TARNEK WA JALDAK, Afghanistan - Subterranean aqueducts, or karez in Persian, have provided rural Afghan villages with water for centuries in a land perpetually challenged with poor resources. In many places throughout the war torn country, however, karez have fallen into disrepair. The Mississippi National Guard Agricultural Development Team is working in Zabul province, Afghanistan, to help villagers repair the problems caused by years of neglect.
Karez are built by boring a series of wells and tunnels into an aquifer. Water infiltrates from the aquifer into the bored wells and tunnels and is then conducted by gravity over declining elevation in a system of underground channels.
Karez can extend for miles through the countryside and move water, protected from evaporation in the arid climate of southern Afghanistan, to surface canals and eventually reservoirs or basins.
Rural Afghans use the collected water for everything from cooking to crop irrigation.
While the system remains fairly efficient, it does require upkeep. The ADT helps villages evaluate what type of work is needed to repair and maintain their karez.
Periodically, the silt must be cleared to prevent it from clogging the channels. Additionally, the walls of the karez often need to be reinforced or redug after a cave in.
"Sediment builds up over time," said Sgt. Bradley Thomas, a security force member of the ADT. "We look for blockages in the karez and any signs of collapsing in the karez walls."
After evaluating the karez's condition, the ADT loans the villagers the equipment to make the necessary repairs and picks it up again when the project's complete.
"We periodically check on their progress when we visit," said Sgt. Paul Marshall, an agricultural specialist with the ADT. "A lot of times villages cooperate and pass the equipment."
Villages working together to make karez repairs is common because often karez provide water to villages located near one another. It is also common for the ADT to drop off gear to villages that are higher or lower on the same karez.
The amount of time a village needs the equipment depends on the length of karez that the village is responsible for and the extent of the required repairs.
"A village may keep equipment for a month, or they might keep it the whole winter," Marshall said. "It just depends."
The Zabul ADT has currently dropped of three sets of karez cleaning equipment to various villages throughout the Tarnek Wa Jaldak district of Afghanistan. They plan to drop off four additional sets in the near future.