List of Abbreviations I

LIST OF ABBREVIATIONS

• ATAWAS Association of Tanzania Water Suppliers
• CBWSO Community Based Water Supply Organisations
• COWSOs Community Owned Water Supply Organizations
• CMIP5 Coupled Model Inter-comparison Project Phase 5
• DAWASA Dar es Salaam Water Supply and Sanitation Authority
• DEWAT Decentralized Wastewater Treatment Systems
• DCOM Design, Construction, Supervision, Operation and Maintenance
• EIA Environmental Impact Assessment
• EIS Environmental Impact Statement
• EMA Environmental Management Act
• ENSO El Nino-Southern Oscillation
• ERB Engineers Registration Board
• EWURA Energy and Water Utilities Regulating Authority
• GCMs Global Climate Models
• GHGs Greenhouse gases
• IHP International Hydrological Programme
• ICOLD International Commission on Large Dams
• ITCZ Inter-tropical Convergence Zone
• IOD Indian Ocean Dipole
• IPCC Intergovernmental Panel on Climate Change
• IWA International Water Association
• NAWAPO National Water Policy
• NEMC National Environmental Management Council
• NMAIST Nelson Mandela African Institution of Science and Technology
• NWSDS National Water Sector Development Strategy
• RCPs Representative Concentration Pathways
• RUWASA Rural Water Supply and Sanitation Agency
• SADC Southern Africa Development Community
• SDGs Sustainable Development Goals
• SST Sea Surface Temperature
• UNESCO United Nations Educational, Scientific and Cultural Organisation
• UNFCC United Nations Framework Convention on Climate Change
• UWSSA Urban Water Supply and Sanitation Authority
• UDSM University of Dar es Salaam
• URT United Republic of Tanzania
• TAWASANET Tanzania Water Supply and Sanitation Network
• WMO World Meteorological Organization
• WSDP Water Sector Development Programme

LIST OF TABLES

Table 3. 1: Mean annual river discharges for some of the principal rivers of Tanzania ......................................................................................................40
Table 3.2: Run-Off Coefficients for Different Surfaces ......................................................................................................50
Table 4.1: Minimum water requirements for various categorised domestic users ......................................................................................................71
Table 4.2: Institutional Water Demands........................................72
Table 4.3: Water requirements for ports and stations...................................73
Table 4.4: Specific industrial water requirements 74
Table 4.5 Industrial Water Demand (m3/ha/d) for future industries 75
Table 4.6: Approximate withdrawals and consumptions, not accounting for ambient temperature or plant efficiency. 76
Table 4.7: Commercial Water Requirements 77
Table 4.8: The IWA ‘Best Practice’ Standard Water Balance 80
Table 4.9: Consumers’ Peak Factors 84
Table 4.10: Peak factors for known population in the area 85
Table 5.1: Recommended pipe C-values (New pipes) 90
Table 6.1: Most Commonly Used Pump Types 103
Table 6.2(a): Selection of types of pumps for water supply by the head needed 106
Table 7.1: Recommended water treatment flow sheets for the most common water sources in Tanzania 108
Table 7.2: Important parameters for the design of lamella plate settler. 124
Table 7.3: Typical Performance of Slow Sand Filters 127
Table 7.4: Different sizes of media in a Roughing filter 133
Table 7.5: Comparison of Sludge Dewatering Systems 155
Table 9.1: Standard Break Pressure Tank of 5 l/s – 25 l/s 174
Table 11.1: Different models of prepaid water meters piloted in various WSSAs and in selected districts 212 Table 12.1 Common Standards Used in Water Projects 218
Table 12.2: Soil logging of borehole or test pit 224
Table 12.3: Number of blows comparison to soil type based on SPT 226
Table 13.1: Different roles of stakeholders in project planning and design stage 229
Table C.1:Common Daily Percentage Consumption Patterns 240
Table C.2: Determining Supply Deficiencies 240
Table D.1Design requirements and partial safety factors (BS 8007) 245
Table D.2 Cylindrical tanks: elastic analysis 1 250
Table D.3 Cylindrical tanks: elastic analysis 2 251
Table E.1: Most Commonly Used Pump Types 253
Table E.2: Specific Speeds for rotordynamic pumps 257
Table F.1: Altitude and temperature values (Factor B) 273
Table G.1 Design Guidelines for Horizontal Roughing Filters 277
Table I.1: Principle cations and anions associated with water hardness 288
Table I.2: Scale of Hardness (classification of hard waters) 288
Table I.3: Compounds Producing Temporary and Permanent Hardness 289

LIST OF FIGURES
Figure 2.1: Projects Planning Process 20
Figure 5.1: Longitudinal section of pumping main showing hydraulic gradient and characteristic curve 92
Figure 5.2: Distribution System Basic Layouts 93
Table 5.3 Characteristics of Different Pipe Materials 100
Figure 7.1: Flow sheets for treatment of lake water, dam, reservoir (multiple water intakes) 110
Figure 7.2: Flow sheets for treatment of surface water with pesticides 110
Figure 7.3: Flow sheets for treatment of deep well water with fluoride 110
Figure 7.4: Flow sheets for treatment of deep well water with iron and manganese 110
Figure 7.5: Flow sheers for treatment of upland stream with no soil erosion 110
Figure 7.6: Flow sheets for treatment of imported water with high natural organic matters 110
Figure 7.7: Flow sheets for treatment of very turbid surface water or silted lowland stream 111
Figure 7.8: Flow sheets for treatment of water with cadmium, selenium, arsenic, mercury, lead, copper, uranium, chromium, cyanide and nickel 111
Figure 7.9: A Typical Skimmer 113
Figure7.10: The Head loss Calculation Formula Through Screens (Source: Poppel, 1982). 114
Figure 7.11: Typical Trapezoidal Section of a Grit Channel 116
Figure 7.12: Single and Common Section Type of Grit Channels 116
Figure 7.13: The Schematic Layout Plan of a Grit Chamber With Proportional Sutro Weir 117
Figure 7.14: Cross Section through the Grit channel 117
Figure 7.15: Typical layout plan of a sand trap for a small scheme 118
Figure 7.16: Longitudinal cross section 118
Figure 7.17: Transverse cross section 119
Figure 7.18: Cylindrical sedimentation tank 121
Figure 7.19: Rectangular sedimentation tank 122
Figure 7.20: Typical Purpose Built Lamella Settler 123
Figure 7.21: Typical Purpose Built Lamella Settle 124
Figure 7.22: Pilot Lamella Settler installed at Nadosoito, in Monduli district, Tanzania for Dam water treatment (Courtesy, K. Njau, 2020). 125
Figure 7.23: (a) A cross section of the Slow Sand Filter (SSF) 126
Figure 7.24: A diagram of Dissolved –air flotation mechanism 136
Figure 7.25: Diagram of a Cascade aerator 140
Figure 7.26: Ozonation Process 146
Figure 7.27: Gravity thickener plan and height 154
Figure 8.1: Configuration of Capacitive Deionization 166
Figure 8.2: Sketches showing installation of a nanofiltration unit. 167
Figure 9.1: The four functional zones of a continuous flow settling basin 173
Figure 11.1: Water Kiosk/ Point with a prepaid meter in Kishapu E-Water point and in Sangara village Babati. 214
Figure E.1: Classification of rotary pumps (Source: MoW Design Manual, 2009, 3rd Edition). 254
Figure E.2: Section through single stage end suction centrifugal pump 255
Figure E.3 Axially split multistage pump 255
Figure E.4: Radially split ring section multistage pump 256
Figure E.5: Types of Positive Displacement Pumps 257
Figure E.6: Duplex – two piston pump 258
Figure E.7: Hand pump with single-acting, bucket piston 260
Figure E.8: Types of Rotary Pumps(Coker, 2014 #2381) 261
Figure E.9: Turbine pump 262
Figure E.10: Submersible Pump (Source: Water Supply Design Manual, 2009) 263
Figure F.1: Modern diesel generator set 266
Figure F.2: Biogas Generator 267
Figure F.3: Windmill driven water pumping 268
Figure F.4: Arrangement for solar driven pumping of water 270
Figure F.5: Diurnal Power Generation from a Solar PV Panel. 272
Figure G.1:Layout of Horizontal-Flow Roughing Filter 279
Figure G.2: Layout of Upflow Vertical-Flow Roughing Filters 280
Figure G.3: Layout of the Dynamic intake and Dynamic roughing filter 280
Figure G.4: Schematic diagram of processes affecting water quality during the bank filtration process 281
Figure J.1: Typical Example Linearized rainfall at Different Return periods 293
Figure J.2: Typical Example IDF Curve 293

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