1. Groundwater avoiding the single story
Dr Roger Parsons
Parsons & Associates Specialist Groundwater Consultants

2. The next half hour . . . The single story Some context
Eight discussion points
Some concluding thoughts

3. The single story . . .

4. Some context . . .
I do not need to explain the current water situation to this audience
Below average rainfall over the past 3½ yrs has contributed to critical water shortages
Severe water restrictions have been applied to the agricultural sector, the industrial sector and the urban environment
This has had a devasting impact on the economy, and in particular the poorest of the poor
Day Zero was a useful tool, until it became a political football
While Day Zero is off the table for now, nothing has changed
Our dams are empty, we haven’t had significant rain and we have no idea how much rain we will have in the next 4 months

5. Some context
In spite of this, groundwater has continued to play an important role
About 13 % of the volume of municipal water in the Western Cape Province is source from groundwater
This includes some 62 towns and villages – this in spite of the collapse of hydrogeological skill within the DWS and the absence of hydrogeological knowledge at decision-making and management levels
There is plenty of evidence that groundwater levels across the Western Cape Province have not been significantly impacted by the drought
It remains of interest to me that since the onset of this drought, no information about the state of aquifers has been presented – but much comment from the so-called water experts

6. Some context . . . Water BCP Development of plans Supply interventions
Demand management

7. Water BCP . . . 90 facilities across the province
Programme rolled out in 3 parts
Work assigned in parcels
Hydrogeologist, driller, tester, engineer
Later – safety, licensing
Hydrogeologist - engineer

8. Teamwork . . .

9. Borehole construction . . .
Pump – 110mm
Riser – 50 mm
Obs.tube – 40 mm
Min. – 140 mm

10. Position of boreholes . . .

11. Pumping regime . . . Initial demand estimate Hydrogeologists target
Safe yield through testing
Engineer to confirm demand
AADD, peak demand
Treatment losses
Demand sometimes double
that of target
Communication

12. Pumping regime . . . Once demand sorted out
How do we match yield with demand
Low and slow (24 hr)
Short and sharp (6 hr)
Pumps continually switching on and off
Iron and oxygen
Balance between pumping rate, duration, fluctuating demand and storage

13. Pumping regime . . .
0.73 ML/d
0.42 ML/d

14. Pumping rates . . . Drilled two boreholes Tested better borehole
No guidance on untested borehole
Engineers were then left to make hydrogeological decisions

15. Groundwater quality . . . What is groundwater quality?
Stabilisation and disinfection
. . . but no T. Alk?
SANS 241 standard suite of analyses
SANS No Class II WHO
Colour & turbidity and odd metals
Iron
Nitrate

16. Groundwater treatment . . .
Hydrogeologists not qualified
Recommendations problematic
As an aside
Extra yield
SANS 241 and treatment
Expensive
O&M

17. Operation & Maintenance . . .
Dr Jude Cobbing been warning us for years
Its not the aquifer, but management
Maintenance of treatment plants
Adoption by facility management
Hydrogeological and engineering support

18. Some concluding thoughts . . .
The droughts not over . . .
We are experts at what we do
We have to provide useful information to those that need it
We have to guide and educate
We have to work as a team and nobody is the top dog

19. Thank you Acknowledgements
Gavin Kode and the Water BCP office team
Andy Cuninghame and Angelos Yainnou
Our team of hydrogeologists, drillers, testers, engineers,water treatment specialists, water laboratories, various national, provincial and local government officials