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3.4 Drinking Water Ponds in Spate Irrigation Systems. Drinking water in spate irrigated areas: main issues. Low annual rainfall Deep water table / sometimes fluoride groundwater Public tubewells out of order Water from ponds – for humans and livestock: Polluted
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Drinking water in spate irrigated areas: main issues • Low annual rainfall • Deep water table / sometimes fluoride groundwater • Public tubewells out of order • Water from ponds – for humans and livestock: • Polluted • Limited duration of storage • Major reason for hardship
IMPORTANCE OF DRINKING WATER PONDS: LOCAL HINDU SAINT IN PAKISTAN STILL REVERRED BECAUSE OF THE POND HE MADE
Traditional system – shallow ponds, water being use by humans and livestock alike
IMPROVED DRINKING WATER PONDS • Have reliable water storage for long period • Have ‘relatively’ clean water • Have ponds well maintained
IMPROVED DRINKING WATER PONDS Reliability • Close to flood inlet • Make ponds deep enough (4-7 meters) to reduce evaporation • Trees on banks of ponds to further reduce evaporation • Where available clay lining • Plastic lining – adequately anchored and covered with at least 30 cm of soils to avoid punching
CONSTRUCTING DRINKING WATER PONDS Cleanliness/ water quality • Fencing to avoid animal tresspassing • Use slow sand filter to pump water from reservoir • Cascade system – water overflowing from other (livestock) pond after sediment settled in it • Use of sediment trapping vegetation in the overflow structure • Later, sometimes: wells near ponds fed by leakage
CONSTRUCTING DRINKING WATER PONDS Ease of maintenance • Gentle slope • Sediment trap (can be part of livestock pond) • No entry of livestock
Hand Pump Sand Filter Filter of graded layers of sand Appropriate for potable water
IMPACTS • Availability of potable water for humans • And livestock • Reduced out migration • Decreased 40 % enteric disorder cases • Provide sediment free water
In spite of importance experience from Balochistan (Pakistan) indicates that maintenance of ponds is main challenge Only 25% of ponds was well maintained. Those that were well-maintained were: • Close to primary schools or mosks • Were used by visiting nomads as well, who paid for the use of the ponds for their livestock
Maintenance • Management is important: • Cleaning out the silt • Protecting the ponds from animals tresspassing • Collecting funds for caretaker and maintenance
Maintenance of Community Ponds Fencing or trenching– against tresspassing animals Collecting funds for guarding and cleaning
OR: TO BE ALLOWED TO TAKE WATER YOU HAVE TO FIRST REMOVE SILT.. WOMEN WITHOUT A HUSBAND EXEMPT FROM THIS DUTY
Manual maintenance limits the capacity of the community ponds Local organisation
Introduce scraper boards to maintain harvesting ponds will make them deeper and stronger – longer storage time Local organisation