Sandy Elsworth Independent Consultant AJEWatercom Focus on groundwater Not on gw levels or CC impact on gw supplies in this short presentation Focus on boreholes and borehole management ID: 227853
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The Nymandhlovu Remediation Programme, Zimbabwe
Sandy ElsworthIndependent ConsultantAJEWater.comSlide2
Focus on groundwaterNot on
gw levels or CC impact on gw supplies in this short presentationFocus on boreholes and borehole managementExperience in Ethiopia, Tanzania and
Zimbabwe
Each year 10,000 boreholes are drilled in Zimbabwe – funded through UNICEF predominantly
Achieving water securitySlide3
Borehole functionality
50% not working after 15 yearsSlide4
Probably around 300,000 boreholes in country
Of which around 100,000 no longer functional.Unicef has a programme commencing in December 2014 to address 7,400 problem boreholesHowever this is always seen in the context of a pump failure, not a borehole issue.Tender typically delivered by a drilling company – who simply want to drill new
Lack of expertise and equipment to inspect and address borehole issue.
Zimbabwe BoreholesSlide5
Climate Change and WR Planning Issues paper published September 2014GW serves 70% of the pop
Recognised as critical in CC adaption“Yet its planning, development and management has received very little attention…”“…almost no monitoring of groundwater levels…”
Vision, and Climate ChangeSlide6
Addressing 3 core issues of
gw management:Inspect and remediate existing rather than drill
Proper testing programme
Long term monitoring and management
Nymandhlovu ProjectSlide7
Brief background
Bulawayo is Zimbabwe’s 2
nd
city
Population 650,000
Water primarily supplied from 6
seasonal dams
Cholera present in 2008
Average rainfall 590mm
But Effective
gw
recharge
Approx
3% of rainfall
CC modelling suggests surface runoff
Could be reduced to zero under
Some scenariosSlide8
Result of 12 month projectSlide9
Historic Information searchInternal Inspection of boreholes
Fishing, air lifting, flushing, re-inspectionStep test – at least 4 steps 60 minutesCRT – at least 1 day, up to 3 days3 primary delivery mains to WTW. Use of hydraulic model (EPANET)
Correct pump sizing for current, drought, operational variability, and CC conditions
Training on site and in office
ProgrammeSlide10
Appropriate Technology
Boreholes Inspection UnitsSlide11
Appropriate Technology
Test Pumping
EquipmentSlide12
Common Issues in BoreholesSlide13
Boreholes are abundantly distributedWhen a problem, the immediate response is typically: Drill another
Train borehole operators and managersRegular water level measurementsProtect headworksInspect, clean, fish, remediate existing before redrill
Invest in long term borehole and
gw management – training, equipment, resources
Conclusions