UNITED REPUBLIC OF TANZANIA I DANISH INTERNATIONAL DEVELOPMENT AGENCY ° DANE DA 8 2 4 LIBRARY •• . , INTERNATIONAL REFERENCE'1 CENTR T Z.R U 8 2 ,-OR CCWIWJXI7Y v/AT£3 SUPPLY'AX • SANITATION (IRC) : ^'-.^ RUVUMA WATER MASTER PLAN I SUMMARY ' VOLUME ,000009 '•1:;'l;:::.;:':;.': :.;.::..'. "«••: •.;;;;-:';• GARL BRO • COWICONSULT • KAMPSAX-.KRUGER *;. ;i UNITED REPUBLIC OF TANZANIA DANISH INTERNATIONAL DEVELOPMENT AGENCY • DANIDA RUVUMA WATER MASTER PLAN SUMMARY VOLUME 3 0 jj LIBRARY, INTE^vATIorC'L R .!;-:_• ;<?.-;.'~E I C£i\'7.'-?£ F: R CC:.::'-:'. • .1 ( / WA s £R C JPPLY | AND SAAiTA'TOA li-C) [• ! P.O. L<O.\ G3M/O. 210!; AD 7ho Kar | Tal. (070) 8i43 1i oxi. 141/1 v2 I / s !| LO: CARL BRO • COWICONSULT • KAMPSAX - KRliGER • CCKK 1982 GUIDE TO RUVUMA WATER MASTER PLAN POPULATION 3/2, 4A/2/4, 12/3 DEVELOPMENT LIVESTOCK 3/2, 4A/2/3/5, 12/2 FRAMEWORK AGKICULTURE 3/2, 4A/3/5, 11/3, 12/2 INDUSTRY 3/2 INVENTORY 5A/1, 12/4 VILLAGES AND DEVELOPMENT 4A/4 EXISTING TRADITIONAL W.S. 4A/6, 12/5 WATER SUPPLY IMPROVED W.S. 4A/6 HUMAN CONSUMPTION 3/5, 5A/4, 12/8 WATER USE AND LIVESTOCK DEMAND 3/5, 5A/4, 12/9 DESIGN CRITERIA TECHNICAL ASPECTS 3/5, 5A/4 a. a. TECHNOLOGY OPTIONS 5A/5, 12/7 WATER SUPPLY WATER QUALITY 3/5, 4A/6, 4B/7, 5A/3, 12/5/10/11 PLANNING CRITERIA SOURCE SELECTION 3/6, 4B/7, 12/5 PRIORITY CRITERIA 3/5, 5A/2, 12/12 COST CRITERIA 5A/2/6, 12/12 u _] REHABILITATION 4B/8 > PROPOSED SINGLE VILLAGE SCHEMES 4B/8 SUPPLIES GROUP VILLAGE SCHEMES 4B/8 SCHEME LAY-OUT AND DETAILS 5B, 5C, 5D ECONOMIC COST 3/6, 4B/9/1O, 5B, 5C, 5D FINANCIAL COST 3/6, 4B/9/10 STRATEGIES 3/6, 4B/10 PROGRAMME 3/6, 4B/10 IMPLEMENTATION ORGANISATION 3/6, 4B/11, 12/6 PARTICIPATION 3/6, 4B/10/11, 12/6 RAINFALL 3/3, 7/3 EVAPORATION 3/3, 7/4 HYDROLOGY RUNOFF 3/3, 7/5/6 MODELLING 3/3, 7/7 BALANCES 3/3, 7/7/8 GEOLOGY 3/4 9/5 GROUNDWATER DOMAINS 3/4 9/7 HYDROGEOLOGY GEOPHYSICS 3/4 9/8 CHEMISTRY 3/4 9/9 GROUNDWATER DEVELOPMENT 3/4 9/12 DRILLING 3/4 9/11 WATER RELATED IRRIGATION 11/4, 12/9 PROJECTS HYDROPOWER 11/4 NOTES THE CHAPTERS REFERRED TO ARE THOSE WHERE THE MAIN DESCRIPTIONS APPEAR. THE REFERENCE CODE 5A/6 MEANS, VOLUME 5A, CHAPTER 6. CONTENTS VOLUME 3, SUMMARY Page 1. INTRODUCTION 1.1 1.1 General 1.1 2. DEVELOPMENT CONTEXT 2.1 2.1 Regional character 2.1 2.2 Development strategies ' 2.3 2.2.1 General 2.3 2.2.2 Agriculture 2.4 2.2.3 Livestock 2.6 2.2.4 Fishing 2.7 2.2.5 Industry 2.7 2.3 Population growth and village development 2.8 2.3.1 Population growth 2.8 2.3.2 Village character 2.10 2.3.3 Village facilities 2.13 2.4 Existing water supply structure 2.15 2.4.1 Improved water supplies 2.15 2.4.2 Design and construction 2.15 2.4.3 Operation and maintenance 2.16 2.4.4 Traditional sources 2.16 3. HYDROLOGY AND SURFACE WATER RESOURCES 3.1 3.1 General 3.1 3.2 Rainfall 3.2 3.3 Evaporation 3.5 3.4 Runoff 3.6 3.5 Index area studies 3.9 3.6 Water balances 3.10 3.7 Recommendations 3.12 4. HYDROGEOLOGY AND GROUNDWATER RESOURCES 4.1 4.1 Geology and structure 4.1 4.1.1 Geology 4.1 4.1.2 Structure 4.2 4.2 Geomorphology 4.3 4.3 Groundwater occurrences 4.4 4.3.1 The Basement Complex 4.4 4.3.2 The Karroo basins 4.7 4.3.3 Neogene deposits 4.8 4.3.4 Springs 4.8 4.4 Groundwater chemistry 4.9 4.4.1 The Basement Complex 4.9 4.4.2 The Karroo Basins 4.9 4.4.3 Neogene deposits 4.9 4.4.4 Springs 4.10 4.5 Geophysical investigations 4.11 4.6 Drilling programme 4.11 4.6.1 Results of drilling 4.11 4.6.2 Recommendation for future drilling 4.12 4.7 Future hydrogeologic data collection 4.14 CONTENTS VOLUME 3, SUMMARY Page 5. WATER USE AND DESIGN CRITERIA 5.1 5.1 General 5.1 5.1.1 Study methodology 5.1 5.1.2 Village inventory 5.1 5.1.3 Household surveys 5.2 5.2 Priority criteria 5.3 5.2.1 General 5.3 5.2.2 Selection of scheme type 5.3 5.2.3 Implementation 5.6 5.3 Water quality criteria 5-9 5.3.1 General 5.9 5.3.2 Water sampling and testing 5-9 5.3-3 Analyses and presentation 5.10 5.3.4 Evaluation and application 5.13 5.4 Design criteria 5.16 5.4.1 General 5.16 5.4.2 Planning period 5.18 5.4.3 Water demand 5.18 5.4.4 Peak factor 5.19 5.4.5 Storage 5.20 5.4.6 Level of service 5.20 6. FUTURE WATER SUPPLY 6.1 6.1 General 6.1 6.2 Source selection 6.4 6.3 Layout of future water supply systems 6.5 6.4 Cost estimates 6.10 6.5 Implementation 6.12 6.5.1 Strategy 6.12 6.5.2 Construction procedure and programme 6.12 6.5.3 Operation and maintenance 6.13 6.5.4 Recurrent costs 6.13 6.6 Organisation and Management 6.14 7. WATER RELATED PROJECTS 7.1 7.1 General 7.1 7.2 Irrigation 7.2 7.2.1 Agricultural conditions 7.2 7.2.2 Irrigation potentials in Iringa Region 7-5 7.2.3 Irrigation potentials in Ruvuma Region 7.6 7.2.4 Irrigation potentials in Mbeya Region 7.7 7.2.5 Recommendations on irrigation 7.8 7.3 Hydropower 7.10 7.3.1 Power supply situation 7.10 7.3.2 Hydropower development 7.12 7.3-3 Hydropower potential assessment 7.13 7.3.4 Hydropower potential in Iringa Region 7.13 7.3.5 Hydropower potential in Ruvuma Region 7.14 7.3.6 Hydropower potential in Mbeya Region 7.15 7.4 Conclusions and recommendations on hydropower 7.16 CONTENTS VOLUME 3, SUMMARY Page 8. MAIN RECOMMENDATIONS 8.1 8.1 General 8.1 8.2 Hydrology 8.1 8.3 Hydrogeology 8.2 8.4 Water Quality 8.3 8.5 Water Engineering 8.3 8.5.1 General principles 8.3 8.5.2 Scheme priority 8.4 8.5.3 Source selection and design 8.5 8.5-^ Scheme construction 8.6 8.5.5 Operation and maintenance 8.7 8.5.6 Organisation and management 8.8 8.6 Water-Related Projects 8.9 8.6.1 Irrigation 8.9 8.6.2 Hydropower 8.10 8.7 Recommendations from the Socio-Economic Studies 8.11 8.7.1 Design criteria 8.11 8.7.2 Complementary programmes 8.11 8.7.3 Organisation at village level 8.12 8.7.4 Village participation 8.12 8.7.5 Operation and maintenance 8.13 1.1 1. INTRODUCTION 1.1 General Improvements in the rural water supply situation in Tanzania have in recent years grown into a major policy matter for the central Government. Policy decisions regarding provision of piped water supplies giving ease of access to domestic points and providing clean, potable and dependable water have been taken. The objective of serving every villager is still quite distant although remarkable progress is being made. On a national basis approximately UQ% of the rural villages are presently served while the regions under study are lagging behind this figure with an average percentage supplied of 22$. These figures, however, do not take account of the schemes not operating nor of the proportion of population served. The benefits of an improved water supply are i.a. shorter walking distances, higher reliability and health improvements. The improved water supply, when combined with education in better hygienic practices, and the improved health facilities should be able to contribute to the general well-being of the rural population. This volume purports to summarise some of the main topics of the Water Master Plan. One of these is the development context outlining the plan- ning framework while the hydrology and hydrogeology studies are concerned with establishing the extent of the resources, surface water as well as groundwater. The present water use in the villages is studied and appro- priate design criteria derived after which the main plan has been pre- pared. Finally, the potential for development within other water-using sectors, like irrigation and hydropower, has been evaluated. 2.1 2. DEVELOPMENT CONTEXT 2.1 Regional character Ruvuma Region has a predominantly agricultural based economy, with almost the entire population depending on agriculture for their liveli- hood although just over 5 per cent of the total area is cultivated. The c lima to logical and topographical variations in the region result in considerable variations of life-style and densities. In the west of the region the higher land form and lake influence leads to mean annual rainfalls of 1,300 mm. The highest densities and most productive agriculture is found in this area. To the east of the region the land becomes more undulating and climatic- ally dryer with rainfalls reducing to around 1,000 mm mean annual values.