The document discusses geological, hydrogeological and groundwater quality maps of the Molopo-Nossob basin region covering parts of Botswana, Namibia and South Africa. It provides details on the maps produced at different scales showing the geology, thickness of aquifers, borehole yields, transmissivity, and concentration of total dissolved solids, nitrates and fluoride in groundwater. Chemical data from databases of the three countries are presented on maps to indicate spatial variation in groundwater quality in the region. Treatment methods for removing excess chemicals from groundwater are also briefly covered.

1. Geological and
Hydrogeological Maps
And Groundwater Quality Maps

2. Groundwater
Resources
1:1,000,00
0
Groundwater
Pollution and
Vulnerability
1:1,000,00
0
The Pre-Kalahari
Geological Map
1:1,000,00
0
Namibia
Geological Map
1:1,000,00
0
Hydrogeological
Map
1:1,000,00
0
Hydrogeological
Map
1:2,000,00
0
Groundwater
Resources Map
1:2,500,00
0
HM Nossob 2419 1:500,000
HM Vryburg 2522 1:500,000
HM Kimberly
2722
1:500,000
HM Upington-
Alexander Bay
2718
1:500,000
Isopach Map of
the Kalahari
Group
1:2,500,0
00

3. Age million
years ago
Era Supergroup Group/Formation
<85 Cretaceous to
Recent
Kalahari Beds
65-145 Cretaceous Flow basalts and dolerite intrusions
(feeder dykes and sills)
145-360 Carboniferous to
Cretaceous
Karoo Stormberg Lava
Lebung (Ntane,
Mosolotsane)
Ecca
Dwyka
490-552 Cambrian Nama
552-2,500 Proterozoic to
Cambian
Waterberg
Dolomites
Olifantshoek
>2,500 Archean Various groups of rock formations
Geological Time – Rocks
considered in Molopo-Nossob
Basin

4. Botswana Namibia South Africa This Report
Dolerite intrusions
and dykes
Dolerite
intrusions and
dykes
Dolerite
intrusions and
dykes
Dolerite Sills
Stormberg lava Kalkrand Drakensberg Stormberg
Ntane Fm Etjo Clarens FM Ntane
Mosolotsane Fm Neu Loore Mosolotsane
Beaufort Kule Fm Beaufort
Otshe Fm Auob Auob Ecca
Kobe Mukorob Mukorob
Ncojane Nossob Nossob
Dwyka Dwyka Dwyka Dwyka
Karoo
Supergroup

6. Cross Section along the SAB,
Namibia
< Fig.2-1 Geological Cross Section of Study Area >

7. Thickness of the Kalahari Beds

8. Borehole yield
0 0 .5 1 1 .5 2 2 .5
1 0
L o g ( Y i e l d ) m 3
/ h
0
1 0
2 0
3 0
4 0
5 0
6 0
7 0
8 0
9 0
1 0 0
Probability%
D o lo m it e K a n y e
O lif a n t s h o e k B o t s w a n a
B a s a lt S A B
( 6 9 )
( 1 6 )
( 1 3 )
0 0 .5 1 1 .5 2 2 .5
1 0
L o g ( Y i e l d ) m 3
/ h
0
1 0
2 0
3 0
4 0
5 0
6 0
7 0
8 0
9 0
1 0 0
Probability%
K a la h a r i S A B
K a la h a r i B o t s w a n a
( 3 8 )
( 3 7 )

9. Borehole yield
0 0 .5 1 1 .5 2 2 .5
1 0 L o g ( Y i e l d ) m 3 / h
0
2 0
4 0
6 0
8 0
1 0 0
Probability%
N t a n e N c o j a n e
N o s s o b S A B
D w y k a B o k s p it s
( 1 2 )
( 7 )
( 7 )

10. Borehole yields Ecca
0 0 .5 1 1 .5 2 2 .5
1 0
L o g ( Y i e l d ) m 3
/ h
0
1 0
2 0
3 0
4 0
5 0
6 0
7 0
8 0
9 0
1 0 0
Probability%
N c o ja n e
K a n g
D u t lw e
S A B
B o k s p it s
( 4 2 )
( 3 8 )
( 2 1 )
( 1 9 )
( 4 8 )
E c c a
b o r e h o le s

11. Borehole yields m3
/h
0 .0 1 0 .1 1 1 0 1 0 0
Y ie ld m 3 /h
K a la h a r i - B o t s w a n a
K a la h a r i - S A B
B a s a lt - S A B
N t a n e - N c o ja n e
E c c a - D u t lw e
E c c a - N c o ja n e
E c c a - S A B
E c c a - B o k s p it s
N o s s o b - S A B
D w y k a - B o k s p it s
O lif a n t s h o e k - B o t s w a n a
D o l o m it e - K a n y e
E c c a - K a n g

12. Country Yield Classes (median borehole yield)
<1.8
m3
/h
1.8-7.2
m3
/h
7.2-18
m3
/h
>18
m3
/h
<0.5
m3
/h
0.5-3
m3
/h
3-15
m3
/h
>15
m3
/h
0.0-0.1
l/s
0.1-0.5
l/s
0.5-2.0
l/s
2.0-5.0
l/s
>5.0
l/s
Used Medium High
Borehole Median Yield Classes
Used

13. Groundwater Potential
Map over Molopo-Nossob
Basin

14. Transmissivity Ecca
0 0 .5 1 1 .5 2 2 .5 3
1 0
L o g ( T ) m 2
/ d
0
1 0
2 0
3 0
4 0
5 0
6 0
7 0
8 0
9 0
1 0 0
Probability%
N c o ja n e
A ll t o g e t h e r
B o k s p it s
D u t lw e
( 1 1 )
( 1 7 )
( 6 8 )
( 4 0 )
E c c a
b o r e h o le s

15. Transmissivity (T) versus Borehole
Yield (Q)

16. Transmissivity Ecca
1 1 0 1 0 0 1 0 0 0
T r a n s m i s s i v i t y m 2 / d a y
E c c a - D u t lw e
E c c a - B o k s p it s
E c c a - A ll t o g e t h e r
E c c a - N c o ja n e

17. Groundwater Quality
Parameters Considered for the Molopo-
Nossob Basin:
 Total Dissolved Solids, TDS
 Nitrate NO3
 Fluorid F
 Chloride Cl (only for recharge assessment, CMB)

18. Country Data bases containing information of
TDS, NO3
, F and Cl in groundwater
Botswana National Borehole Archive
Water Quality database
Investigation reports over selected areas
Namibia Groundwater database GROWAS
South Africa Water Management System

19. WHO
1993
Botswana, 2000
Guide-
line
Value
Class 1
Ideal
Class 2
Acceptable
Class 3
Max.
Allowable
mg/l mg/l mg/l mg/l
TDS 1,000 450 1,500 2,000
NO3
45 45 45 45
F 1.5 0.7 1.0 1.5

20. Namibia, 1991Namibia, 1991 South Africa, 2006South Africa, 2006
Group A
Excellent
Group B
Good
Group C
Low
Health
Risk
Group D
Unsuitable
Class I
Operational
Class II
Max allowable for
limited duration
mg/l mg/l mg/l mg/l mg/l mg/l
975* 1,950* 2,600* >2,600* <1,000 1,000-2,400
45 90 180 >180 45** 45-90**
1.5 2.0 3.0 >3.0 <1.0 1.0-1.5

21. Number of chemical data used
Parameter Botswana Namibia South
Africa
Total
TDS 2,147 * 6,905 7,367 14,933
NO3
1,560 6,898 5,464 13,922
Fluoride 1,648 5,870 5,391 12,909
* data included from neighboring areas outside the
Molopo-Nossob Basin

22. 1 7 ° E 1 8 ° E 1 9 ° E 2 0 ° E 2 1 ° E 2 2 ° E 2 3 ° E 2 4 ° E 2 5 ° E 2 6 ° E
- 2 8 ° S
- 2 7 ° S
- 2 6 ° S
- 2 5 ° S
- 2 4 ° S
- 2 3 ° S
- 2 2 ° S
W in d h o e k
S t a m p r ie t
G o c h a s
G o b a b i s
A m in iu s
A r o a b B o k s p it s
H u k u n t s i
K a n g
N c o ja n e
T s a b o n g
W e r d a
G o o d h o p e
M m a b a t h o
K u r u m a n
V a n z y ls r u s
T o s c a
4 5 0
1 , 0 0 0
2 , 0 0 0
5 , 0 0 0
1 0 , 0 0 0
2 0 , 0 0 0
5 0 , 0 0 0
T D S
m g /l

23. TDS in the Nossob Aquifer

25. 1 7 ° E 1 8 ° E 1 9 ° E 2 0 ° E 2 1 ° E 2 2 ° E 2 3 ° E 2 4 ° E 2 5 ° E 2 6 ° E
- 2 8 ° S
- 2 7 ° S
- 2 6 ° S
- 2 5 ° S
- 2 4 ° S
- 2 3 ° S
- 2 2 ° S
W in d h o e k
S t a m p r ie t
G o c h a s
G o b a b i s
A m i n iu s
A r o a b
B o k s p it s
H u k u n t s i
K a n g
N c o ja n e
T s a b o n g
W e r d a
G o o d h o p e
M m a b a t h o
K u r u m a n
V a n z y ls r u s
T o s c a
2 7
4 5
9 0
1 8 0
N it r a t e
N O 3
m g /l

26. 1 7 ° E 1 8 ° E 1 9 ° E 2 0 ° E 2 1 ° E 2 2 ° E 2 3 ° E 2 4 ° E 2 5 ° E 2 6 ° E
- 2 9 ° S
- 2 8 ° S
- 2 7 ° S
- 2 6 ° S
- 2 5 ° S
- 2 4 ° S
- 2 3 ° S
- 2 2 ° S
W i n d h o e k
S t a m p r ie t
G o c h a s
G o b a b is
A m i n i u s
A r o a b B o k s p it s
H u k u n t s i
K a n g
N c o ja n e
T s a b o n g
W e r d a
G o o d h o p e
M m a b a t h o
K u r u m a n
V a n z y l s r u s
T o s c a
0 . 7
1 . 5
4
6
8
F lu o r id e
m g /l

27. F in the Nossob Aquifer

30. Treatment Methods
TDS (costly and sophisticated)
Ion Exchange
Reverse Osmosis
Electro Dialysis
Distillation
Blending
NO3 (not uncomplicated)
Reverse Osmosis
Ion Exchange
Blending
F (difficult)
Adsorption on Active Alumina
Ion Exchange
Membrane Processes
Reverse Osmosis
Electro Dialysis

31. Data used in chemical maps
1 7 ° E 1 8 ° E 1 9 ° E 2 0 ° E 2 1 ° E 2 2 ° E 2 3 ° E 2 4 ° E 2 5 ° E 2 6 ° E
- 2 9 ° S
- 2 8 ° S
- 2 7 ° S
- 2 6 ° S
- 2 5 ° S
- 2 4 ° S
- 2 3 ° S
- 2 2 ° S
- 2 1 ° S
N it r a t e
N O 3
1 7 ° E 1 8 ° E 1 9 ° E 2 0 ° E 2 1 ° E 2 2 ° E 2 3 ° E 2 4 ° E 2 5 ° E 2 6 ° E
- 2 8 ° S
- 2 7 ° S
- 2 6 ° S
- 2 5 ° S
- 2 4 ° S
- 2 3 ° S
- 2 2 ° S
- 2 1 ° S
T D S
1 7 ° E 1 8 ° E 1 9 ° E 2 0 ° E 2 1 ° E 2 2 ° E 2 3 ° E 2 4 ° E 2 5 ° E 2 6 ° E
- 2 9 ° S
- 2 8 ° S
- 2 7 ° S
- 2 6 ° S
- 2 5 ° S
- 2 4 ° S
- 2 3 ° S
- 2 2 ° S
- 2 1 ° S
F l u o r i d e
F