A little more on irrigation:
Nan garhar's Arable Land
Nan garhar's Critical Irrigation Infrastructure
Existing primary irrigation structures are in red. The dashed lines represent the primary canals and the red fields indicate the area irrigated.
The blue areas represent projected irrigation structures. The small blue circles represent locations that will support and benefit from medium size watershed dams. (The dams will also double down as macro-hydro power production plants). The longest red dotted line at the center is Nan garhar's Grand Canal (or Dur anta Canal). At the Eastern end of the Grand Canal is the Dur anta Dam, which serves as the Canal's single source of water. The Grand Canal feeds about 35,000 hectares of arable land. It's primary artery is 72 kilometers long with well over a thousand kilometers of secondary and tertiary canals.
The Dam, the Grand Canal, and all associated structures were built with the financial and technical assistance of the Soviet Union between 1965 and 1967 (approximate). The Dam was designed to provide 50 cubic meters of water per second to the canal while simultaneously using the remaining available water to generate 11.5 megawatts of power. Due to a number of reasons, the Grand Canal now receives only between 30 and 40 cubic meters of water per second, while the electrical output is typically around 5 or 6 megawatts (with a high of 8.5 megawatts and a low of .5 megawatts).
The canal as it runs through Sur-kh Rod District
Pump station #1 in South J-alalabad
Failed secondary canals near Ad-ah Farms
The canal's maintenance facilities. Unchanged since 1965...asbestos roofing and all.
The Grand Canal has about 25 major siphons. The picture above is the up-stream control gate of the fifth siphon along the canal. The siphon was damaged some 15 to 20 years ago and has been deteriorating at an accelerated pace ever since. If it were to completely fail, it would shut off irrigation to a tremendous about of land, and cut off the livelihood of more than 600,000 Afghans.
Over the last year, we spent a great deal of time documenting and cataloging the problems with the Grand Canal. And then we spent a bit of time setting up a major repair project, which will start in a few months.
Posted by paul at February 21, 2008 04:15 PM