Overview of Botswana’s Water Resources Demand and Deficits Projections up to Year 2035

1. Overview of Botswana’s Water Resources Demand and DeficitsProjections up to Year 2035 By Thato Seth Setloboko

2. 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

3. Overview of Botswana’s Water Resources Rainfall Distribution Zambia Namibia 650 600 550 500 450 Zimbabwe Namibia 400 350 300 South Africa Source: Bhallotra 1981 250

4. Surface Water Drainage Patterns Zambezi River Okavango River OkavangoDelta Okwavalley LimpopoRiver Molopo River Source: Botswana Atlas

5. Major Surface Water Works on the Limpopo

6. Planned Surface Water Works on the Limpopo

7. Available Surface Water Resources Estimated yield of existing and planned reservoirs

8. 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

9. 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.

10. Groundwater Exploitation • Department of Water Affairs: • 27 wellfields for major village water supply • Water Utilities Corporation: • DukwiWellfield for Sowa Town, Nata & Dukwi • Botswana Power Corporation: • PajeWellfield 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 officially-registered boreholes in Botswana (BNWMP – Review, 2006) Currently this type of setup is under review by MMEWR The ultimate goal being that all the wellfields are coordinated by one organisation

11. 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

12. NWMPR Water Demand Calculations

13. NWMPR Water Demand Calculations

14. 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.

15. Water Demand Clusters 17 Clusters

16. Water Demand Clusters 17 Clusters

18. Water Demand/Deficit & Surplus - 2035

19. Water Demand/Deficit & Surplus - 2035

20. Water Demand/Deficit & Surplus - 2035

21. Water Demand/Deficit & Surplus - 2035

22. 3 -Dimensional Surplus and Deficit Map of the Clusters

23. 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

24. 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.

25. 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.

26. 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

27. THANK YOU Kealeboga