Date post: | 21-Jun-2015 |
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Understanding Afghan Traditional Irrigation and Water Management Systems
Prepared by: Ron Savage, Field Program, DST Spin Boldak, Kandahar Feb. 2011
Issues: •Most of Afghanistan’s water for irrigation, industry and household use depends on winter snowfall. •There is little watershed management taking place in the country •Lack of access to water contributes to poverty and exacerbates tribal tensions
Precipitation and Evapo-Transpiration Comparison Kandahar and Kunduz
SPIN BOLDAK
•Rainfall primarily in winter and spring
•Spin Boldak ET exceeds precip. in very month, including winter,
• Precip. Mostly absent throughout growing season
•Few mountains to capture snow
•Need for water storage and irrigation for successful agriculture
•Winter wheat largest crop in ha
•Wind is a major contributor to ET and crop stress
KUNDUZ
•More favorable with all parameters
•Frost is probably an issue
•Kunduz has more precip. than ET in winter and spring.
Understanding Afghan Traditional Irrigation Systems
Gravity flow sources:
- Reservoirs
- Wadis or ruds
- Rivers & streams
- Springs
Two principal types of irrigation systems: Gravity Flow and Pumped
Pumped sources:
- Tube wells
- Hand dug (bauris)
- Boreholes
- Reservoirs
Delivery: - Diesel Electric Pumps -Solar Elecric Pumps -Hand pumps -Pipes & Hoses -Buckets
Delivery: - Canals -Furrows - Pipes -Hoses
Surface Water systems
Reservoirs & Check Dams
Rock dam for reservoir Sand bag check dams
Canal Systems
Earthen canals: Low costs, 20-30% seepage, high maintenance, lower volumes of water, erosion
Concrete lined: High cost, <5 seepage, low maintenance, high volumes of water, dangerous
Irrigated vineyards outside Kandahar
Secondary canal for field distribution
Traditional Pumping system
Pumped from shallow well
Typical pumping system for shallow wells, usually less than 40 m, hand dug well
A farmer quickly clears the way for rushing irrigation water being pumped from pools in the wadi below
Note: The yellow arrow indicates the flexible hosing used to carry the water, which is then pumped into a higher channel, and from there into the furrows
Traditional
• Stream diversion
• Flood or runoff systems
• Karez
• Handdug wells (bauri)
• Waffle grid cultivation
Diversion ditches are often built along permanent streams.
A Karez seen from the air
Kerez systems
Kerez systems – two views
Kerez Systems
Upstream: Kerez maintenance shaft
Downstream: Permanent flow with mulberry trees
Wadi Systems
Floodwater diversion
Wadis wander, making runoff diversion challenging
Ever widening wadi channel Protection Walls help protect banks but should normally not be made of concrete. Gabions are a much better
option
Traditional structures require ongoing maintenance
Canals not lined with concrete usually require constant maintenance
Kerez shafts often fill up with sediment or can be intentionally plugged
Smaller catchments catch more runoff and are more effective at controlling erosion than one large catchment.
Use of gabions to control bank erosion
Challenges
• Lack of concern for watershed management by donors
• Short-term thinking and lack of scaling up of interventions results in piecemeal approach
• Land tenure issues and feuding between communities
• Lack of trained extension staff
• Poor oversight of projects
Recommendations
• Better use of CFW to address watershed management and irrigation issues
• Train up a large cadre (hundreds) of watershed managers
• Increased use of gabions
• Reforestation, afforestation and agroforestry
• Use traditional water management as starting point