SPATE IRRIGATION IN PAKISTAN 1.3

History of spate irrigation in Pakistan Some bunds in Balochistan are more than 5000 years old The construction of spurs and bunds in the Bolan river (Balochistan) during dry period was one of first opportunities to control surface flows and resulted in strong population increase In 2600 BC Source: French Archeological Mission

Spate irrigation - globally Pakistan has the single largest area under spate irrigation The area is 9% of the total irrigated area Even so – it is completely ignored

Spate irrigation in Pakistan – where? Major area NWFP DI Khan, Tank, Laki Marwat, Bannu, Karak Punjab DG Khan, Rajanpur, Mianwali Sindh Dadu, Larkana, Jamshoro, Thatta, Karachi Balochistan Kacchi, Sibi, Jal Magsi, Kharan, Qila Saifullah, Musakhel, Barkhan, Lorelai, Las Bela

HILL TORRENT AREAS

DI KHAN

TANK

TAUNSA AREA

DG KHAN

KACCHI PLAINS

KACCHI PLAINS MIDDLE SECTION as elsewhere based on earthen bunds distance from river as important as head tail huge fields many braiding stream (flat gradient)

Type of spate irrigation systems: (1) large systems along the Kohi Suleiman, Kirthar Range and in Kacchi Plains

Type of spate irrigation (2) smaller systems – coastal Las Bela, interior Balochistan, smaller rivers from Koh-i-Sulaiman and Kirthar Range

Type of spate irrigation (3) mini systems – mountain systems

General typology Spate irrigation in Pakistan: World’s largest area under spate irrigation: 1.4 M ha! Equivalent to 9% of canal irrigated area Completely neglected Very low productivity compared to other countries Major poverty pocket in the country Important environmental functions Some areas short range from mountain to Indus Special characteristics Based on large earthen bunds and deflectors Overstretched area – command area compared to floods is large – many areas only irrigation < 1 in 5 years Few floods (<5), elsewhere more floods Large fields Mainly flat and sandy areas Interventions Based on failed civil engineering concepts not appropriate to spate system – high failure rate (65%) Lost its dynamism – no new development Role of local government in management was positive but is weakened Spate irrigation seen as nuisance (flood damage) not as potential

Potentials Potential is large: Water management: Revive and resource local management by communities and local government Rationalize area under spate irrigation Ensure affordable availability of bulldozers in public or private sector Stay away from inappropriate civil engineering solutions, such as weirs and flood storage dams. Instead – attenuate and regulate flood patterns Appropriate civil engineering solutions are: flow dividers, fixing flood canal inlets, bed stabilizers, improved/ strengthened earthen bunds (gabion sections, abutments), guide bunds, controlled field inlets and overflow structures Improve drinking water supply – improved shallow ponds and subsurface dams Combine spate irrigation with groundwater use and recharge

Potentials Potential is large: Agronomy and livestock: Improved soil moisture conservation (mulching, ploughing, improved equipment) Improve yield of major crops such as sorghum by better varieties and better soil moisture conservation – in Eritrea yield of sorghum is 8 times more!! Better marketing and processing of promising minor crops (guar, sesame for instance) Improve prospects for local vegetables and medicinal plants Spate irrigated forestry (gum arabica) Improve local livestock varieties (Bagh Nari) Improved fodder for livestock

Potentials Potential is large, if managed well: Environment Stabilizes the area, avoid desertification Recharge of groundwater Local wetlands and lakes High biodiversity, indigeneous plants Low external input (organic) farming