By
Thato Seth Setloboko
Climate and Topography of Botswana
 Average rainfall of 450 mm
 Temperatures range from below zero in the south
and can be greater than 40 degrees
 Topography is relatively flat with low rates of
surface runoff and deep (>250 m) overburden
 Low rates of recharge to its groundwater with about
40 mm in small areas in the Chobe District in the
north and over most of the Kalahari region it 18mm
or approaches zero
Overview of Botswana’s Water Resources
Rainfall Distribution
Zambia
Namibia
650
600
550
500
450
Zimbabwe
Namibia
40
0
350
300
250
South Africa
Source: Bhallotra 1981
Surface Water Drainage Patterns
Zambezi
River
Okavango River
Okavango Delta
Okwa valley
Limpopo River
Molopo River
Source: Botswana Atlas
Major Surface Water Works on the Limpopo
Name of Dam
River Name
Capacity (Mm3)
Gaborone
Ngotwane
141.4
Shashe
Shashe
85
Nnywane
Nnywane
2.3
Bokaa
Metsimotlhaba
18.5
Ntimbale
Tati
26.4
Letsibogo
Motloutse
100
Planned Surface Water Works on the Limpopo
Name of Dam
River Name
Capacity (Mm3)
Dikgatlhong
Shashe
400
Lotsane
Lotsane
40
Thune
Thune
90
Available Surface Water Resources
Estimated yield of existing and planned reservoirs
Name of Reservoir
Existing
Gaborone
Nywane
Bokaa
Shashe
Letsibogo
Ntimbale
Planned
Dikgatlhong
Lotsane
Mosetse
Thune
River
Yield /annum (Mm3)
Notwane
Nywane
Metsemotlhaba
Shashe
Motloutse
Ntshe
9.4
1.9
4.9
25.3
30.8
2.95
Shashe
Lotsane
Mosetse
Thune
62
6.5
7.92
4.18
Available and Potential W/Resources-Cont.
SURFACE WATER RESOURCES
 Developed Surface Water Resources
= 88 680 000 m3/Year
 Potential New Surface Water Resources / Undeveloped
= 72 680 000 m3/Year
Facts
a) No more dam sites available
b) Concentrated along the Eastern Corridor
b) Chobe-Zambezi Transfer Scheme, Lesotho Highlands
Water Transfer to Botswana
 Negotiations with Riparian States /Transboudary
Groundwater Occurrence Patterns
Influenced by geology and climate
Limited, both in quantity and quality
is unevenly distributed over the country
And considered non-renewable
Depth to gw: < 40m in the N and E to >
100m in the drier central and south-western
parts.
Groundwater Exploitation
•
Department of Water Affairs:
• 27 wellfields for major village water
supply
•
Water Utilities Corporation:
• Dukwi Wellfield for Sowa Town, Nata
& Dukwi
•
Botswana Power Corporation:
• Paje Wellfield for Morupule Colliery
•
District Councils (MLG):
• Several wellfields for rural village
water supply
•
Debswana Mining Company:
• For Orapa, Letlhakane, Damtshaa &
Jwaneng Mines
•
Private Farmers
• For livestock-watering and limited
irrigation
At present there are around 25,000 officiallyregistered boreholes in Botswana
Currently this type of setup is under review by MMEWR
(BNWMP – Review, 2006)
The ultimate goal being that all the wellfields are coordinated by one
organisation
Available and Potential W/Resources
GROUNDWATER RESOURCES
 Developed Sustainable Groundwater Resources
= 46 306 000 m3/Year (Does not include Wellfields that are
operated by Mines and other Privately owned
Boreholes)
 Potential New Groundwater Resources / Undeveloped
= 5 501
500 m3/Year
Unknown
a) Saline Groundwater Resources- not yet quantified
b) Other Aquifers – e.g Sand rivers, CKGR, Sorilatholo, etc.
c) Groundwater Recharge Rates
 Research required
NWMPR Water Demand Calculations
Dam
Yield
Existing surface water Resources
Gaborone
Shashe
Molatedi
letsibogo
Nnywane
Bokaa
Moshopa
Ntimbale
Existing Groundwater
Resources
Potential surface water
resources
Lotsane
Dikgatlhong
Thune
Potential ground water
resources
Botlhapatlou*
Mabule Dolomite Cluster*
Kodibeleng (Coal Bed
Methane)*
per Dam
Cumulative Yield
9,400,000
25,300,000
7,300,000
30,800,000
1,930,000
4,500,000
2,950,000
6,500,000
9,400,000
34,700,000
42,000,000
72,800,000
74,730,000
79,230,000
82,180,000
88,680,000
46,306,000
134,986,000
6,500,000
62,000,000
4,180,000
141,486,000
203,486,000
207,666,000
2,555,000
1,095,000
210,221,000
211,316,000
1,861,500
213,177,500
NWMPR Water Demand Calculations
Total Yield
Demand
Household, Commercial
and Institutions
2010
2011
2012
1
2
3
134,986,000 134,986,000 134,986,000
206,999,790 187,723,164 190,853,885
100,353,290
103,193,964 106,324,685
Livestock
77,197,500
36,424,200
36,424,200
Irrigated Farms
Mining
% Demand met
1,314,000
28,135,000
0.65
19,970,000
28,135,000
0.72
19,970,000
28,135,000
0.71
2013
2014
2015
2016 Comments
4
5
6
7
134,986,000 141,486,000 203,486,000 207,666,000
193,979,920 197,220,964 200,542,124 203,494,978
Extract from Volume 5/6
109,450,720 112,691,764 116,012,924 118,965,778
Extract from Volume 8 pg 125 & Statistics
36,424,200 36,424,200 36,424,200 36,424,200 from Agric
Extract from Volume 8 pg 169, 175 &
19,970,000 19,970,000 19,970,000 19,970,000 Statistics from Agric
28,135,000 28,135,000 28,135,000 28,135,000 Extract from Volume 5/6
0.70
0.72
1.01
1.02
Water Demand Clusters Investigations
This project was formulated to evaluate the Water
Demands, Water Resources and to Propose the most
Cost Effective Water transfer Schemes to deliver the
Water from Source to the Demand Centre. Concluded
in 2008.
Water Demand Clusters
17 Clusters
Cluster No.
1
2
3
4
5
6
7
8
9
10
Cluster Name / Definition
Kgalagadi South (Khokohtsa - Werda - Tshabong - Bokspits )
Gaborone (Ramotwsa - Lobatse - Kanye - Mochudi – Molepolole)
Jwaneng – Letlhakeng-Sekoma
Mahalapye
Serowe – Palapye
Tswapong
Bobirwa
Selibe-Phikwe village and associated villages - not Bobonong
Francistown
Masunga
Water Demand Clusters
17 Clusters
Cluster No.
11
12
13
14
15
16
Cluster Name / Definition
Nata –Gweta-Sowa Town
Central East – Since merged with Clusters 8 & 13
Boteti -including Orapa and Letlhakane
Chobe- (Kasane - and river side villages and Kavimba)
Maun-(Maun, Toteng and Sehitwa and Delta villages )
Ngamiland (North West Ngamiland and Pan Handle
villages)
17
Ghanzi-Mamuno-Kang
Water Demand/Deficit & Surplus - 2035
Cluster
Number
1 - Kgalagadi
Water
(m3/day)
Demand Water Resource Surplus/Deficit
(m3/day)
(m3/day)
2,740
No regional water
resources available
-2,740
2 - Greater
70,800 – Gabz Only
74,400
-111,900
Gaborone
115,500 - Rest of Cluster
65,000
39,000
40,000
-2,700
South
186,300 - in Total
3 - Jwaneng
34,00 - Jwaneng Mine
5,700 - Rest of Cluster
39,700
4 - Mahalapye
42,700
Comment
Tsabong currently
provided for by a
sort
of
small
'wellfield' - series of
spread out boreholes
Assumes
average
inflow into both
Gaborone
and
Bokaa Dam
Assumes
large
operational
wellfield developed
at Botlhalotlau
Assumes full high
pumping resource
from
Masama
Water Demand/Deficit & Surplus - 2035
Cluster
Number
Water
(m3/day)
Demand Water Resource Surplus/Deficit
(m3/day)
(m3/day)
Comment
5 - Serowe Palapye
6 - Tswapong
30,100
12,800
-17,300
Not part of study
Not part of study
7 - Bobirwa
Not part of study
Not part of study
8 - Phikwe
40,300 - BCL Mine
53,300
8,400
Letsibogo
Dam
main resource
44,900 - in Total
46,100
221,700
175,600
Assumes
Lower
Shashe
Dam
Completed - Dam
on boundary of
Cluster 8 and 9
Not part of study
Not part of study
4,600 - Rest of Cluster
9
Francistown
10 - North East
-
Water Demand/Deficit & Surplus - 2035
Cluster
Number
11Nata/Gweta
Water
(m3/day)
Demand Water Resource Surplus/Deficit
(m3/day)
(m3/day)
6,300
12 - Central No Longer a separate
East
Cluster
13 - Orapa
48,200 - Orapa Mine
32,700
No Longer a
separate Cluster
43,000
3,200 - Rest of
Cluster
51,400 - in Total
14 - Kasane
2,900
Extensive from
Chobe
26,400
Comment
Assumes Mosetse
Dam and Gweta
developed
This Cluster was
amalgamated into
Clusters 13 and 8
-8,400
Assumes
Letlhakane Mine
closed. Flat rate
for Orapa - does
not include Saline
Option
Uncertain and not Potentially huge
included in study transfer
from
Chobe /Zambezi
Water Demand/Deficit & Surplus - 2035
Cluster
Number
Water
(m3/day)
Demand Water Resource Surplus/Deficit Comment
(m3/day)
(m3/day)
15 - Maun
15,200
22,000
6,800
Assumes
new
wellfields Gomoti,
Kunyere
all
developed
16
Ngamiland
5,900
30,000
24,100
Extensive
Groundwater
available although
not developed at all
17 - Ghanzi Kang
5,400
22,900
17,500
Ncojane Basin fully
developed
3 -Dimensional Surplus and Deficit Map of the Clusters
Shashe and Lower Shashe Dams
Greater Gaborone
Cluster 17
Cluster 1
Water Supply
To address deficits and ensure a sustainable Water
Supply:
 Conjunctive use of Surface and Groundwater
Resources – Eastern Corridor
- Availability of dams/reservoirs
- Aquifers to recover during wet seasons
- Artificial recharge of aquifers with excess runoff
- Groundwater should be used as back-up since
surface water is lost to evaporation processes
 Use Saline Groundwater where possible e.g Debswana
 Construct Water Transfer Schemes
Proposed Transfer Schemes
The net effect of the proposed schemes is
to supply those clusters presumed to have a
water deficit by 2035, namely Clusters 1, 2,
4, 5 and 13, with water from the Clusters in
surplus.
RECOMMENDATIONS
 Water Demands and Deficit Projections are based on
Population growth rates that needs to be monitored as time
goes on to see if changes in population and life styles add
extra demand to high density population clusters.
 There is a need to reduce losses in the reticulation and bulk
transfer systems.
 Industry should be encouraged to move/locate in areas
where water resources are more plentiful.
 Large new industrial developments should be encouraged
(financially even?) to locate where water resources are not
so scarce
 International agreements to water sharing, water
abstraction should be started as soon as possible.
RECOMMENDATIONS
 Surface water must be used preferentially to groundwater
wherever possible even if this means higher water costs.
 Transfer schemes should be prioritized and carried out in a
structured progressive manner so that each new section can
link into providing on going water supply
 Saline water should be sought as an alternative for process
water at all mines
 Water supply projects for private and public sector (including
parastatals) should be integrated - for example the recent BPC
Paje wellfield area project will be supplying water from north
of Serowe to Palapye whilst the NSC is going to be providing
water from Palapye to Serowe - ie: there will be two pipelines
carrying water in opposite directions along the same section of
road
THANK YOU
Kealeboga