UNITED REPUBLIC OF TANZANIA
MINISTRY OF WATER
Lake Nyasa Basin Water Board
PREPARATION OF AN INTEGRATED WATER
RESOURCES MANAGEMENT AND
DEVELOPMENT PLAN
FOR THE LAKE NYASA BASIN
Hydropower Report
May 2013
United Republic of Tanzania
Ministry of Water
Hydropower Report
Date: May 2013
This report has been prepared for the Ministry of Water of the United Republic of Tanzania in accordance with the terms and
July 2012
conditions of Contract: ME 011/2010/2011/C/08 Consultancy Services for preparing the Integrated Water Resources
Management and Development Plan for the Lake Nyasa Basin. Funds are made available by the International Development
Association (IDA) and the United Republic of Tanzania.
The opinions expressed are those of the authors and may not represent the views of the IDA or those of the United Republic
of Tanzania.
SMEC International Pty Ltd cannot accept any responsibility for any use of or reliance on the contents of this report by any
third party.
Table of Contents
ABBREVIATION and ACRONYMS ................................................................................ ii
1
INTRODUCTION .................................................................................................. 1
1.1
Literature Search, Data Collection ........................................................................ 2
1.2
Data and Information Review ................................................................................ 2
1.3
Consultations, Workshop and Field Visits ............................................................. 3
1.4
Software Programs ............................................................................................... 3
2
HYDROPOWER SITUATION REVIEW ................................................................ 4
2.1
Nyasa Basin .......................................................................................................... 4
2.2
Preview for Tanzania Power Sector ...................................................................... 5
2.3
Existing Hydropower in Nyasa Basin .................................................................... 7
3
HYDROPOWER WATER PLAN........................................................................... 8
3.1
Water Demand ..................................................................................................... 8
3.2
Water Demand Management ............................................................................... 9
3.3
Planning Objectives, Development Plan ............................................................. 10
3.4
Reservoir Operating Rules.................................................................................. 10
4
POTENTIAL HYDROPOWER DEVELOPMENT SCHEMES ............................. 12
4.1
Potential Hydropower in Nyasa Basin ................................................................. 12
4.2
Prioritized Projects (PSMP 2009)........................................................................ 13
4.3
Other Identified Potentials (mini grid) .................................................................. 16
5
FINDINGS and RECOMMENDATIONS ............................................................. 17
APPENDICES ............................................................................................................... 18
Hydropower Report - Preparation of an Integrated Water Resources
Management and Development Plan for the Lake Nyasa Basin (May 2013)
Page i
TABLES
Table 1 - Thermal Power Plants in Tanzania Power Grid ................................................ 6
Table 2 - Hydropower Plants in Tanzania Power Grid ..................................................... 6
Table 3 - Water Abstraction Certificates/Applications ...................................................... 8
Table 4 - Potential Hydropower in Nyasa Basin ............................................................ 12
Table 5 - Prioritized Future Hydropower Projects under PSMP 2009 (Nation Wide) ....... 13
Table 6 - Other Potentials in Nyasa Basin ..................................................................... 16
FIGURES
Figure 1 - Lake Nyasa Basin and its Rivers ................................................................... 4
Figure 2 - Tanzania Power Generation Mix ................................................................... 5
Figure 3 - Existing Basin Hydropower Contribution to National Power Grid .................. 7
Figure 4 - Basins’ Future Hydro Contribution in MW to the Electric Grid ..................... 12
Figure 5 - Basins’ Future Hydro Contribution in % to the National Grid ....................... 13
Figure 6 - Illustrative Diagram for Upgraded Rumakali Hep Concept .......................... 14
Fig App B1 - Rumakali River Rating Curve......................................................Appendix B
Fig App B2 - Ruhuhu at Masigira Rating Curve ...............................................Appendix B
Fig App B3 - Songwe River at Kasumulu Rating Curve ...................................Appendix B
APPENDICES
Appendix A - Photo Documentation
Appendix B - Rating Curves
Appendix C - Map Licensed Hydropower Plants, Prioritized Projects (PSMP 2009)
Appendix D - License Holders for Hydropower
Hydropower Report - Preparation of an Integrated Water Resources
Management and Development Plan for the Lake Nyasa Basin (May 2013)
Page i
ABBREVIATIONS AND ACRONYMS
CRC
Cumecs
CWS
CWSS
EF
FAO
FRG
GWh
HEP
IPP
ITCZ
Km
kW
kWh
= critical rule curve
= cubic meter per seconds (m3/sec)
= Community Water Supply and Sanitation
= Commercial Water Supply and Sewerage
= Environmental Flows
= Food and Agriculture Organization of the United Nations
= Federal Republic of Germany
= Giga Watt hour
= Hydro Electric Power
= Independent Power Producer
= Inter-Tropical Convergence Zone
= kilometer
= kilo Watt
= kilo Watt hour
LNBWB
= Lake Nyasa Basin Water Board
LocClim
m.a.s.l.
MDGs
Mm3
MoEM
MoW
MW
NEMC
NyM
Ppt
Ph.D
PSMP
NORPLAN
REA
SHP
SMEC
TANESCO
ToR
URT
WRMD
WSDP
= Local Climate Estimator
= meters above sea level
= Millennium Development Goals
= Million Cubic Meters
= Ministry of Energy and Minerals (Tanzania)
= Ministry of Water (Tanzania)
= Megawatt
= National Environmental Management Council
= Nyumba ya Mungu
= Precipitation
= Doctor of Philosophy
= Power System Master Plan
= Norway based consulting firm
= Rural Electrification Agency
= Small Hydro Power
= Snowy Mountains Engineering Corporation
= Tanzania Electric Supply Company Limited
= Terms of Reference
= United Republic of Tanzania
= Water Resources Management and Development
= Water Sector Development Program
Hydropower Report - Preparation of an Integrated Water Resources
Management and Development Plan for the Lake Nyasa Basin (May 2013)
Page ii
1
INTRODUCTION
The Government of Tanzania is presently implementing the Water Sector Development Program
(WSDP) 2006 - 2025. The WSDP targets four areas in the water sector, namely: (i) Water
Resources Management and Development (WRMD), (ii) Community Water Supply and Sanitation
(CWSS), (iii) Commercial Water Supply and Sewerage (CWS) and (iv) Sector Institutional
Strengthening and Capacity Building.
The development of an IWRMD Plan is a key objective of the WRMD component whose
conceptual framework for IWRMD consists of four main components:





Water Supply & Sanitation
Energy (Hydropower)
Irrigation & Drainage
Environmental Services
Other Uses including Industry & Navigation
This report looks at the Hydropower component. It makes an assessment of the hydropower
situation in the basin, water demand, management and development and the potential for
hydropower (Chapter 3-4). Chapter 5 presents the key findings and recommendations.
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 1
1.1
Literature Search, Data Collection
A desk study was undertaken and a number of key stakeholders were visited. These are:
TANESCO, MEM, REA and the MAJI offices in Dar es Salaam. Other offices including the LNBWO
in Tukuyu were visited as well, for data and information collection.
The following data and reports were collected from various institutions/offices in Dar es Salaam
and elsewhere:










Basin Hydrological Report, LNBWO, December 2010
The Water Resources Management Act 2009, GoT, 15th May 2009.
Power System Power Master Plan, MEM/TANESCO, August 2009
A List of Mini Hydropower Potential Sites in Tanzania, TANESCO, August 1996
Topographical Maps, 1:50,000 for the area.
Hydrological Year Book 1950-1959, Ministry of Agriculture, Republic of Tanganyika, 1963
Hydrological Year Book 1965-1970, Ministry of Water Development and Power, United
Republic of Tanzania, 1976
Hydrological Year Book 1971-1980, Ministry of Water, URT, 1980
Water Master Plans for Iringa, Ruvuma and Mbeya Regions, Hydrology Volume 7, Carl Bro et
al 1982
Implementation of Water Master Plan for Iringa, Ruvuma and Mbeya Regions, Hydrology –
Low Flow Gaugings, Reginal Hydrologists, 1988
1.2
Data and Information Review
The following data were reviewed:





Topography and hydrological data and information mainly based on previous
studies/reports. Identification reaches of streams/rivers with potential for hydropower
development.
Relevant stream/river gauging stations. Matching these with the corresponding
catchment/sub-catchments.
Identify time series for the gauging stations and compute its mean values (monthly and
annually) using commercially available computer software programs.
Identify relevant rainfall stations and their time series runoffs were studied to compute
monthly/annual averages for the corresponding catchments to give averages discharges.
These rainfall averages will be compared and used fill gaps identified in the discharge time
series for the flows of the same catchments. Based on these and other key information
(head) from the existing reports preliminary power and energy output were estimated.
During the study period, some interviews to ascertain quality, gaps of data and information
were held with different officials of LNBWO.
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
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1.3
Consultations, Workshop and Field Visits
Consultations
Prior to the basin visit, consultations and discussions with the following officers/institutions were
held with the aim of understanding the government planning objectives related to the energy
sector:
 Ministry of Energy and Minerals:
Assistant Commissioner (Renewable), Mr. Edward Leonard Ishengoma
Senior Energy Engineer, Mr. Leonard Masanja
Senior Energy Engineer, Mr. Juma Mkobya
 TANESCO:
Senior Manager Hydropower Generation – Eng. Costa Rubagumya
Principal Planning Engineer – Eng. Evalder Munisi
 Rural Energy Agency: Director Technical services – Eng. Bengiel Msofe
Workshop
A training workshop on Hydropower in Nyasa was held in December 2012 in Tukuyu with
participants from LNBWO and TANESCO. Information was gathered from the LNBWO/TANESCO
staff:
 Basin Water Officer – Witgal Nkondola
 Basin Environmental Engineer – Innocent Lyamuya
 Lake Nyasa Hydrologist – Damas Mbaga
 TANESCO Officer – Richard Ngwada
The workshop included presentations which were structured and delivered as an interactive
session enabling the participants to discuss and brainstorm on key issues of serious concerns and
challenges facing the basin encompassing issues on IWRMD.
Field Visit
Field visits with the LNBWO counterparts were conducted in December 2013 to inspect nearby
hydrological river gauging and meteorological stations. Also during the same period, the Bugema
Micro Hydropower Plant at Busoka village run by a local Church was visited.
Discussions/explanations on the facility were held at site during the tour (see also Appendix A).
1.4
Software Programs
During this study, an assessment and evaluation of the rainfall spatial distribution within the basin
was carried out using the New LocClim 1.10 program developed by DWD/FAO 2005. New LocClim
is a tool for spatial interpolation of agroclimatic data and specially designed for the interpolation of
agroclimatic data, offering the possibility of producing climate maps from user provided station
data. However, where such station data is unavailable, New LocClim is also capable of producing
climate maps of the average monthly climate conditions taken from the agroclimatic database of
the Agromet Group of the Food and Agriculture Organisation of the United Nations. For free
copies and technical details of this software, the reader is directed to contact agromet@fao.org or
gpcc@dwd.de.
Also, for hydrological assessment and evaluation, free software program was used. Hydrological
time series processing software called Hydrognomon, version 4.1.0 was used in the exercise.
Details on this free software program may be obtained from http://hydrognomon.org.
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
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2
HYDROPOWER SITUATION REVIEW
2.1
The Basin
The study area is comprised of 10 major rivers whose catchments have a total area of about
27,600 km2 as shown in Figure 1 below. The Lake Nyasa is a shared lake between Tanzania,
Malawi and Mozambique with a total drainage area of about 98,700 km2. The Lake Nyasa Basin is
located in the south western part of Tanzania and drains into the Indian Ocean via Lake Nyasa
through Shire River System into the Zambezi River in Mozambique. The major rivers that drain into
Lake Nyasa are Ruhuhu, Songwe, Kiwira, Lufirio, and Lumbira.
Name
Lake Nyasa
Malawi
Mozambique
Mbawa
Mchuchuma
Ruhuhu
Nkiwe
Songwe
Mbaka
Lumbira
Rumakali
Lufirio
Kiwira
total Tanzania
catchment LN
Area
Land Area
(sqkm)
(sqkm)
30,898
62,906
62,906
8,182
8,182
1,878
671
14,211
1,881
2,490
747
2,153
693
1,012
1,888
27,623
98,711
Figure 1 - Lake Nyasa Basin and its Rivers
Basin Topography
The Tanzania portion of the basin is generally mountainous and hilly, with Rungwe, Kipengere
Mountains being the highest of peaks over 2,000 metres above sea level. The lowest land is
around the Lake Nyasa which is 470 metres above sea level on the average. The mountainous
areas in the Ruvuma region are of lesser altitudes than those of the Iringa and Mbeya regions and
most of the region is covered by undulating hills. The characteristic features of the basin, apart
from the Rift Valley system, are the surrounding uplifted and warped plateaus, covering nearly 90
percent of the total basin area. The plateaus represent by far the most common land form. They
are dissected by fault-lines and ravines which are the result of steady erosion that has taken place
since the late Jurassic period.
The oldest plateaus are found at the highest levels from 1,800 to 3,000 m above sea level (i.e. the
Mporoto and Kipengere ranges) while the remaining parts of the basin are occupied by areas
where deposition of the material has taken place notably in the Rungwe Volcanics, in and around
Rungwe district.
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 4
The Rungwe Volcanics, with the Rungwe Mountain (2,960 m.a.s.l.) at its centre of eruption, forms
an area of pronounced topographical relief. The craters, lava flows and volcanic ash covers make
the volcanic area completely different from the rest of the Basin.
Climate
The climate of the Basin is tropical, displaying wet and dry seasonal patterns. It is significantly
affected by the location of the ITCZ. During December to February this zone is located south of the
Basin and the dry and warm north-east monsoon pre-dominates. From March the zone moves
northwards and is located over the Basin and results in the heaviest rainfall of the year. By June
the zone has moved north of the Basin and the colder but dry south-east air streams predominate.
The convergence zone then moves south again, although more rapidly than its northward journey,
and by November it is again situated over the Basin giving rise to some light rains.
Run-off
Streams starts rising in November-December, experience a maximum flow in March-April, and
have their recession period from May to October-November with annual rainfall below 500-800 mm
and the mean annual runoff is generally below 2 l/s/km2. At the other part of the Basin where
annual rainfall is in the range of 1,000-2,500 mm, streams and rivers are perennial, and the mean
annual runoff exceeds 10 l/s/km2. Exceptional high mean annual runoff can be found in areas like
Kiwira River (40 l/s/km2) from the 1,660 km2 catchment at Kyela.
The available hydrological records of several stream flows gauging station were reviewed.
However, this report will not deal with detailed hydrological assessment as the subject will be
handled in a separate report prepared. However, typical river characteristics in terms of river flows
patterns for some selected rivers are given in Appendix B.
2.2
Tanzania Power Sector
Electricity generation players in Tanzania are both the Public (TANESCO) and Private Sector
(IPPs). A significant portion of generation is also supplied through RENTAL Units system.
TANESCO’s generation system consists mainly of hydro and fossil fuel based generation. The
total interconnected system installed capacity from TANESCO, IPPs and RENTAL Units
generation assets amount to about 1,436 MW as per 2012.
Figure 2 - Tanzania Power Generation Mix
The Tanzania power generation mix is shown in Figure 2. Details of each segment are shown in
Tables 1 and 2.
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 5
Table 1 - Thermal Power Plants in Tanzania Power Grid (2012)
Thermal
Plant
Fuel
Songas 1
Songas 2
Songas 3
Tegeta IPTL
Subtotal 1
Gas
Gas
Gas
HFO
Ubungo T
Tegeta T
Subtotal 2
Gas
Gas
Symbion I
Agreko
Symbion II
Subtotal 3
Total (1+2+3)
#
units
IPPs
2
3
1
10
TANESCOs
10
RENTALS
Gas/JetA1
5
HFO
100
HFO
Installed
(MW)
Available
Capacity
(MW)
40
120
40
103
303
38
110
37
90
275
102
45
147
100
43
143
120
100
205
425
875
112
100
205
417
835
Available
Energy (GWh)
Available
Capacity *
8760* 1 (for
max plant
1
factor)
The national grid system constitutes hydropower of about 561 MW installed capacity. Fossil fuel
generating capacity forms the rest, mainly from IPPs (875 MW). Hydro contributes the largest
share of TANESCO’s own power generation.
Table 2 - Hydropower Plants in Tanzania Power Grid (2012)
Plant name
Capacity
(MW)
Mtera
80
Avg
Annual
energy
(GWh)
429
Firm
Annual
energy
(GWh)
195
Commis sioned
Date
Age in
2013
(years)
1988
25
Kidatu
Hale*
Lower Kihansi
New Pangani Falls
Nyumba Ya Mungu
204
21
180
68
8
1,111
91
694
341
36
601
54
492
201
20
1975
1964
2000
1995
1968
38
49
13
18
45
Total
561
2,704
1,564
The total generation from TANESCO own sources in 2008 was 2,985,275,264 kWh out of which
2,648,911,352 kWh or 90% was from Hydro Power Plants.
Total country demand as per 2008 records was 4,425,403,157 kWh, of which 33% was supplied by
IPPs.
Available energy in GWh equals the formula → (Available Capacity in MW) x (hours in a year) x (plant
factor). The latter has been given the maximum of 1 (or 100%) following the PSMP 2009.
1
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 6
2.3
Existing Hydropower in Nyasa Basin
Currently, the Lake Nyasa basin does not have any hydropower generation plant connected to the
national grid such as Rufiji (83%) and Pangani (17%) basins do, as shown below.
Figure 3 - Existing Basin Hydropower Contribution (%) to National Power Grid
However, Lake Nyasa basin is a home to existing mini-hydropower plants with an installed
capacity totaling of about 290 MW according to the source from LNBWO. These are isolated and
off-grid hydropower plants developed by private institutions mostly church missions and dioceses.
Appendix C and D shows a map with list of license holders for water abstractions for the mini/micro
hydropower plants as well as the prioritized projects under PSMP 2009 . Currently, the Basin office
is updating the status of these license holders.
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
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3
HYDROPOWER WATER PLAN
3.1
Water Demand
The Lake Nyasa Basin is currently underutilized in terms of hydropower generation in respect to
the huge amount of water resources it is bestowed with.
The major water use in the basin is for domestic use, irrigation, livestock, industrial use and hydro
power. The Basin has about 364 water abstractions out of which 68% have been granted with a
water permit for domestic use.
Hydromil plants are said to be quite popular in the Basin especially in the Mbinga district, Ruvuma
region. Existing mini-hydropower plants are scattered throughout the Basin and generate electric
power of most of them less than 1,000 kW, to serve communities.
Table 5 - Water Abstraction Certificates/Applications
No.
1
2
3
4
5
6
7
8
9
10
Uses
Domestic
Hydropower
Irrigation
Fish & Farming
Hydromill
Domestic & Irrigation
Domestic & Livestock
Industrial
Livestock
Dom/Irr/Livestock
Total
Ruvuma
Certif.
Appl.
39
7
4
0
6
0
1
1
0
2
60
67
20
1
3
1
0
9
0
0
0
101
Mbeya
Certif.
Appl.
48
2
24
1
0
0
0
14
0
0
89
30
3
4
1
0
0
0
14
1
5
58
Iringa
Certif.
Appl.
51
9
7
0
0
8
1
1
0
0
77
22
3
1
4
0
1
0
1
0
0
32
Total
257
40
41
9
7
9
11
31
1
7
364
Source: LNBWO Hydrology Report 2010
Details of the 40 hydropower license holders are contained in the Appendix B without figures for
quantities of water granted under the licenses. This information was not immediately available from
LNBWO. The total of installed capacity of all the hydropower licence holders is 290 MW.
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 8
3.2
Water Demand Management
Water resources within Lake Nyasa River basin are being managed by LNBWB which was
established in 2002 in accordance with the Water Utilization (Control and Regulation) Act No. 42 of
1974 and its subsequent amendments. This act was repealed and replaced by the Water
Resources Management Act No. 11 of 2009.
The LNBWB comprises of 11 members, drawn from the public institutions and private sector
(including representatives of catchment water committees, LGAs, UWSAs, MoW, private sector
water users and water related sectors). According to the Water Resources Management Act of
2009, the Basin Water Board is a financially and administratively autonomous body.
It is charged to ensure that water resources are managed sustainably, through water governance
and integrated water resources management principles. The Lake Nyasa Water Basin Board in its
duties, it has the following activities:

Data Collection
There is an extensive river flow monitoring network in the Basin. The management of data
collection activities and maintenance of the network infrastructure are however beset with
difficulties. Different software is used like HYDATA, MS Access for processing and data base
management.
The basin has 18 weather stations which are operational although some of them need
replacement of missing/or old instruments such as cylinders, thermometers, evaporation pans,
etc. Apart from that the basin has 31 flow gauging stations and two automatic monitoring
devices located at Ruhuhu Masigira and at Kiwira, Ipyana. Only the one at Ruhuhu is
operational.
Data collection is primarily carried out by gauge readers or meteorological observers who
submit the data to the respective basin sub-offices for further processing, analysis, storage and
dissemination at every end of each month.

Water Allocation
More than 364 abstractions have been registered with provisional or final water use permits.
Currently the water supply is considered sufficient to meet demand. There are procedures for
registering water use permits according to the Water Act of 2009 and its regulations.
Applications from applicants received are analyzed and reviewed after field visits (where
hydrographical reports are prepared). Other information is obtained the District Authorities.
Applications are announced in the official gazette and District’s notice boards. Fiinally, the
application is forwarded to LNBWB for approval or rejection. After approval, provisional or final
grants will be issued.

Coordination of preparation of IWRMD plan
The current policy aims at comprehensive, integrated and holistic management of water
resources, with a basin as the unit for planning. It is intended that the planning process will be
participatory and considers fully all of the environmental, ecological and socio-economic
concerns of the basin stakeholders.
LNBWO will coordinate the establishment of participatory planning procedures, provide
guidance and coordination, and provide technical support for the actual preparation of the
IWRMD plan by the local stakeholders. The planning assumption of this activity is 25 years.
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 9

Other activities of the LNBWO includes but are not limited to Water Resources Assessment
which includes surface water, groundwater, water pollution monitoring and control, borehole
monitoring stations, water quality, sediment loads as well as water demand.
3.3
Planning Objectives, Development Plan
Power generation expansion national plans are drawn up by the Ministry of Energy and Minerals in
collaboration with TANESCO on behalf of the Government and they are usually presented in the
Power System Master Plan which is being updated regularly. Currently, the PSMP which is still in
force is 2009 Update. The author of this report is well informed that this PSMP 2009 is currently
being revised by the MEM/TANESCO team.
There are three planning horizons for the power generation expansion plans as follows:
1. Short term: The short-term plan to 2014 which is considered as fixed, since there are other
options presently available. In this short term plan, there is no major hydropower project
that has been included but the Songwe project (340 MW, 170 MW for TZ) which is a
shared resource between Malawi and Tanzania. Project has been commissioned and
preparations are underway as project site coordinators have been mobilized to the site by
both countries. This is a five year plan which seemed to have been pegged from 2009 as
per PSMP 2009 update.
2. Medium term: The proposed mid-term plan as per 2009 PSMP is for the period from 2015
to 2019 and is mainly based on cost and availability of options. Rumakali Hydro (initially
222 MW) is included in this medium term plan by the Government. Usually, for the midterm
(i.e., 6 years to 15 years) the least cost plan will be selected for implementation.
3. Long term: This is for the period beyond 2020 where the proposed plan includes the
Stiegler´s Gorge hydro complex (Rufiji Basin) as well as Masigira Hydropower 118 MW
(Lake Nyasa Basin) among others projects.
Appendix B presents rating curves for three gauging stations for the three rivers each.
3.4
Reservoir Operating Rules
There are a number of major hydropower projects under consideration at various levels by different
developers. The two projects that are currently under pre-investment review studies are Rumakali
520 MW and Songwe 340 MW.
NEMC and Lake Nyasa Basin Water Office need to collaboratively work with those developers to
establish acceptable reservoir operating rules first so to sustain the environmental management of
the rivers concerned.
In such environment where rules are inexistent, the most logical step to do is to convene and
establish a stakeholders’ working group with representatives from NEMC, Project Developers
TANESCO, LNBWB, District Councils, Irrigation department and other relevant
departments/stakeholders. A set of rules/principles to manage and operate the reservoirs and
associated works would be to:
 Ensure integrity of the head works system;
 Meet entitlement holder’s needs in accordance to with their entitlements;
 Enhance environmental benefits including reserve flows
 Manage water quality;
 Deliver safe and reliable water supply;
 Maximize community benefits.
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
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It is important to understand that where a reservoir is required for water supply purposes (including
storage and releases of environmental water), the benefits of flood mitigation and recreation
cannot always be guaranteed as supply will always take priority.
For Environmental Flows (EF), it is always a challenge how to allocate the environmental flows out
of the available water in the river. However, the basis on which to build the reserve is not
particularly clear to many of us in the water resources fraternity. EF describes the quantity, timing,
and quality of water flows required to sustain freshwater and estuarine ecosystems and the human
livelihoods and well-being that depend on these ecosystems. The formulas for calculation of EF
are many and their numbers tend to increase day by day. This demonstrates that there is no
consensus found so far. Some of the methods are based on hydrologic or statistic values.
Examples are:
1. One method group refers to the average flow rate (MQ) of the river at a given cross section.
The resulting reserved flow varies from 2,5 % of MQ for the Cemagref method applied in
France to 60% for Montana (USA) method applied in the case where fisheries have a high
economic importance. Typically, a figure of 10 % of the average flow is used for reserved flow.
2. 2nd method group refers to the minimum mean flow (MNQ) in the river. The reserved flow
calculated when applying these methods varies from 20% (Rheinland-Pfalz, Hessen [D]) to
100% (Steinbach [A]) of MNQ.
3. 3rd method group refers to the prefixed values on the Flow Duration Curve (FDC). In this group
a large variety of values are chosen as reference:
i.
NMQ7 (the lowest mean value of flow rate in the seven months with the higher natural
discharges),
ii.
NMQAug (the minimum mean flow in August), Q84%, Q361, Q355 and so on.
The author of this report feels it is fair to adopt the method of average flow rate utilizing time series
data of the river. Typically, a figure of 10% of the average flow would be appropriate for reserved
flow as this has been used in similar hydropower projects elsewhere in the country.
However, relevant the Basin authority should take a lead and collaboratively work with key
stakeholders to formulate and establish operational rules even at this stage when various projects
are being designed. Principles and objectives mentioned under this chapter will be worth reviewing
and can be of help and guidance to set the operational rules.
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 11
4
POTENTIAL HYDROPOWER
4.1
Potential Hydropower Lake Nyasa Basin
The full potential of hydropower in Nyasa basin adds up to 1,072 MW (Table 4) which is about 29%
of the projected hydropower generation in the future for Tanzania. Figure 4 and 5 shows Nyasa’s
share in hydropower contribution to the national grid2.
Project/Scheme
Masigira
Rumakali
Songwe (340 MW, 170 for TZ)
Nkiwe River
Lumbira/Luyagala
Kiwira at natural bridge
Lower Kiwira
Total
Potential
Capacity
(MW)
118
520
170
110
100
14
40
1,072
River
Masigira/Ruhuhu
Rumakali
Songwe
Nkiwe
Lumbira/Luyagara
Kiwira
Kiwira
Source: Power System Master Plan 2009 and The Hydropower and Irrigation Study
of Western Tanzania 1976
Table 4 - Potential Hydropower Nyasa Basin
Figure 4 - Basin Future Hydro Contribution in MW to the National Grid
2
The total potential for hydropower nationwide is assessed at 3,748 MW.
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 12
Figure 5 - Basin Future Hydro Contribution in % to the National Grid
4.2
Prioritized Projects (PSMP 2009)
Under the PSMP 2009, GoT and TANESCO have given hydropower development in Nyasa basin
a high priority as can be seen from Table 5. The prioritized Songwe, Rumakali and Masigira
projects have an anticipated total capacity of 808 MW out of 3,243 MW nationwide prioritizsed
project.
Table 5 - Prioritized Future Hydropower Projects under PSMP 2009 (Nation Wide)
Plant/site
Kakono
53
Avg
Annual
Energy
(GWh)
404
Rusumo 90MW (30 MW for TZ)
30
148
Kagera
Upper Kihansi
120
69
Kihansi
Mpanga
144
955
Mpanga
Ruhudji
358
1,928
Ruhudji
1,200
340
5,259
1,832
Rufiji
Mnyera
Taveta
145
850
Mnyera
Rumakali (222 MW upgrade)
520
1,475
Rumakali
Songwe 340 MW (170 MW for TZ)
Masigira
170
118
1,669
664
Songwe
Ruhuhu
Malagarasi Stage III
45
187
Malagarasi
Steiglers Gorge
Ikondo
Total
Power
MW
River
Kagera
Basin
Lake Victoria
Rufiji
Lake Nyasa
(808 MW)
Lake
Tanganyika
3,243
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 13
Under PSMP three projects with a total of 808 MW has been listed. Two of them are at an
advanced stage of design.
- Rumakali Project. The river is a major tributary of the Lufirio. The current plan has been under
review for a possible upgrade from 222 MW to 520 MW by Studio Pietrangeli, Rome. Its new
approach design offer has been under discussion since beginning September 2012.
- Songwe Project. The other, is a multipurpose project shared between Malawi and Tanzania on
the Songwe River. This has been studied to a detailed feasibility level by NORPLAN in association
with COWI and DHI Consulting Engineers. The feasibility study was concluded in December 2003.
Rumakali Project and Inter-Basin Water Transfer
The concept of upgrading Rumakali 222 MW from an earlier designed arrangement in a study
carried out by SWEDPOWER/NORCONSULT in 1997/1998 has been gaining pace. A new design
concept to bring Rumakali to 520 MW is based on Interbasin Water Transfer as shown in the
schematic drawing below (Figure 6).
Figure 6 - Illustrative Diagram for Upgraded Rumakali HEP Concept
The new Rumakali Hydropower project is envisaged to exploit five catchments for a total of more
than 717 km2, namely Rumakali (406 km2); Nyithule + basin 2220 North (113 km2); Kikugu (139
km2); Rumbira (46 km2) and basin 2220 North. The main catchment (Rumakali) will receive the
water transferred from the other basins to the main reservoir of the Rumakali dam through artificial
water ways (canals, tunnels and pipelines).
With respect to the Rumakali reservoir:
o the two northern rivers are located at a higher elevation and therefore the waters drain
by gravity towards the Rumakali reservoir, while
o The two eastern rivers are located at a lower elevation and the waters shall therefore be
pumped to the Rumakali reservoir.
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 14
Each of the five catchments contributes to the supply of a total annual flow of 22.7m3/s, as follows:
o 12.5 m3/s from the Rumakali basin;
o 0.5 m3/s from basin 2220 North of Rumakali Reservoir;
o 4.0 m3/s from Nyitule basin North of Rumakali Reservoir;
o 4.3 m3/s from Kikugu basin East of Rumakali Reservoir;
o 1.4 m3/s from Rumbira basin East of Rumakali Reservoir.
The following aspects should be noted and included in the E&SIA of the scheme:
− the two northern basins are bordering the escarpment of the Lufirio river valley with a main
one originating from Nyituli (a western tributary of the Rumakali river but joining
downstream of the proposed dam;
− the two other catchments on the eastern side from the Kikugu and Rumbira rivers flow
directly to Lake Nyasa without flowing into Rumakali River;
− allocation of reserved flows/environmental flows for the rivers;
− all stakeholders/beneficiaries must be identified; assessment of impact of diverting flows.
Possible consequences to be considered:
 Large volumes are transferred to another flow regime without returns to the same water
regime;
 Rich biodiversity river sections shall be denied of regular water flow;
 As a result, ground water level along those river embankment will decrease proportionately;
 As a result, decline in the receptive capacity of the Natural Habitat along the drained rivers;
 As a result, this will further cause loss of biodiversity and a decline in perennial vegetation.
Clearly, this inter-basin water transfer project must include a comprehensive E&SIA study that
addresses all social, economic and ecological impacts that may be caused by the project
implementation.
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 15
4.3
Other Identified Potentials (mini grid)
In addition to the three prioritized projects under PSMP 2009, hydropower potential is identified in
another nine locations in the basin with a total of 122 MW for off/mini grid connections. These are
listed in Table 6. However, the information is outdated (List of Hydropower and Irrigation Study of
Western Tanzania, MEM, April 1976) and must be reassessed as the source of this data/info is
more than 40 years ago.
Table 6 - Other Potentials in Lake Nyasa Basin
Name of Site
Yungu River at Liuli
20
0.5
Potential
Installed
Power (kW)
90
Mbawa
200
1
1,800
Luwika
200
0.8
1,400
Luaita
Hanga
30
40
0.6
5.2
190
550
Lilondo at Mahanje Mission
150
0.95
1,400
Kitiwaka (Mhangasi River)
50
10.5
5,100
Malisa
75
1.8
1,250
Nkiwe river (stage I-IV)
585
?
110,000
Total
Head (m)
Avg Flow
(m3/s)
121,780 kW or
122 MW
Compiled from “List of Hydropower and Irrigation Study of Western Tanzania, MEM, April 1976
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 16
5
FINDINGS AND RECOMMENDATIONS

Lake Nyasa basin is endowed with plenty of water resources aided by the presence of the Rift
controlled terrain which makes the area suitable for hydropower development.

At present, despite this endowment, the resources are yet to be exploited fully. Currently, the
basin contributes 0% hydropower generation to the national electric grid.

There are 364 water rights license holders issued by LNBWB for mainly water supply,
hydropower, and irrigation of which 40 for small hydropower systems. Total quantity figures of
water flows granted by LNBWB are not available.

At present there are no large dams/reservoirs existing within the basin and so there are no
Reservoir Operating rules.
However, there are major dam projects under consideration at various levels by different
developers. In the future, hydropower contribution from the Lake Nyasa Basin will likely be
about 29% of the anticipated national hydropower contribution. Both anticipated future grid and
off grid power generation are estimated in the order of 1,200 MW.

The two projects that are currently under pre-investment review studies are Rumakali 222/520
MW and the Multipurpose Songwe Project 340 MW. This then calls for LNBWO to take the
lead, work collaboratively with other relevant governmental authorities to coordinate with the
project developers to ensure Reservoir Operating rules are established and in-built in the
design and get approved for future application when these reservoirs come into operation.

For the Rumakali Hydropower site, a water right has been granted by LNBWB to Mufindi Wood
Plantation & Industries Ltd (ref#.:LNBWB/MAKE/0207) for the design capacity of 222 MW.
`
Currently a parallel effort is made by both TANESCO and MoEM to carry out the studies that
propose the plant to be upgraded from 222 MW to 520 MW by an interbasin water transfer
approach. These studies were carried out by the TANESCO commissioned consultant
SWEDPOWER/NORCONSULT in 1998.
This gives rise to concern whether there is an efficient mechanism for notification to the general
public on the intent of granting WR. More importantly, there has to be coordination among
relevant key intergovernmental departments/authorities to avoid confusion.
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 17
APPENDICES
Appendix A - Photos
Appendix B - Rating Curves
Appendix C - License Holders Water Abstraction for Hydropower
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 18
APPENDIX A - PHOTOS
Training Workshop Session in Progress at Tukuyu SMEC Office, December 2012
Water Level Station at Port Itungi and Some of the Visiting Team Members at Lake Nyasa beach
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 19
Gauging Station for Kiwira River in Kyela
Met Station in Kyela
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 20
Gauging Station at Lufirio River
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 21
Bugema Micro Hydropower Plant at Busoka Village
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 22
Bugema Micro Hydropower Plant at Busoka Village
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 23
APPENDIX B - RATING CURVES
Rumakali River is part of Lake Nyasa drainage basin and has two gauging stations i.e. 1RC11A
at Mwakauta and 1RC 12 Nyituli tributary at Kidope. Data from 1RC11A represent inflows to
Rumakali project since it is located at the proposed dam site. Nyituli tributary joins Rumakali
downstream of the proposed site hence its data is not relevant unless a proposal to divert it. The
1996 to 2004 rating curve shown in this Appendix was used to generate 2006 inflows for the
PSMP and it shows the river had discharges ranging from as low as 5 m3/s to as high as 45
m3/s during the period. It is potentially one of the lower cost hydro sites, and that is why
preparation studies had commenced to review, update and further optimize the scheme.
Figure Appendix B1 - Rumakali River rating Curve (Source: PSMP 2009)
Masigira hydropower potential is located on Ruhuhu River, which forms part of Lake Nyasa
drainage basin as well. A well-maintained and operated gauging station 1RB2 is strategically
located close to the proposed intake pond. Data observed at this station represent inflows to the
proposed plant. The rating curve shown in Figure 7 has been used to extend inflows to year
2006 and it shows that the river had discharges ranging from as low as 20m 3/s to as high as
slightly above 100 m3/s during the said period of measurement.
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 24
Figure Appendix B2 - Ruhuhu at Masigira Rating Curve (Source: PSMP 2009)
Songwe River is part of Lake Nyasa drainage basin. Cascades of three hydropower potentials
are located on this river. One gauging station exists close to lake but before the delta. This is
station 1RD1 Songwe River at Kasumulu. The station has been rehabilitated but few rating
programmes have been implemented. The last programme was in December 2008. Extensions
of flow data for Songwe potentials have been derived from this station. The rating curve is as
shown in Figure 9. Although recent rating seems to fit with previous data, the data should be
used with great care since the river has the tendency to shift after every large flood.
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 25
Figure Appendix B3 - Songwe River at Kasumulu Rating Curve (Source: PSMP 2009)
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 26
APPENDIX C - MAP WITH LICENSED HYDROPOWER PLANTS AND
PRIORITIZED PROJECTS (PSMP 2009)
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 27
APPENDIX D - LICENSE HOLDERS for HYDROPOWER
License holder
1
St. Gertrude convent Immiliwaha
2
St. Gertrude convent Immiliwaha
3
4
5
6
7
8
9
10
11
Diocese of Njombe
Nia Njema Need Foundation
Mkonge energy systems co.Ltd
Mkonge energy systems co.Ltd
E A Power limited
Kikundi cha mazingira Luswiswi
Kisangani black smith and Ren. Tech
Ushirika wa utumiaji umeme mlangali
Makete power service limited
12
Makete power service limited
13
Owden Andalwisye Mwaikela
14
15
16
Mufindi Wood Plantation & Indutries
Ltd
SISTERS HOUSE MAGUU
BENEDICTINE FATHERS
17
BENEDICTINE FATHERS
18
19
Wakulma Tea Co.Ltd
Itete Hospital
20
Bulongwa Hospital (ELCT/SCD)
21
Consolata Hospital - Ikonda
River Name
Tel
Lupali (d/s - 640kw),
Boimanda
Lupali (u/s - 183kW),
Kitulila
Madope/Luholomela
Lilondo, Madaba Vill
Kiwira, Ibililo Vill
Kiwira , Lupepo Vill
Kiwira, Kibwe Magereza
Luswiswi
Isigula, Mkiu-Kiyombo
Likingo, Mlangali/Lupanga
Idetele stream/
Usagatikwa & Iledevelo
Idetele stream/
Usagatikwa & iledevelo
754239412
Capacity
MW
Date of
Certificates
Certificates
Box 830 Njombe
0.64
25-Nov-10
LNBWB/NJO/0056
754239412
Box 830 Njombe
0.18
25-Nov-10
LNBWB/NJO/0057
26782033
765357070
Box 54 Njombe
Box 113 Madaba
Box 123 Tanga
Box 123 Tanga
Box
DSM
Box 543 Tukuyu
Box 588 Njombe
Ludewa
P.O.BOX 20128
Makete
P.O.BOX 20128
Makete
1.00
0.90
8.00
6.00
10.00
0.25
0.20
0.25
0.30
7-Sep-10
24-Sep-10
24-Sep-09
24-Sep-09
24-Sep-09
19-May-10
29-Jul-11
28-Jun-10
29-Sep-11
LNBWB/NJO/0061
LNBWB/SONGE/0088
LNBWB/RUNG/0089
LNBWB/RUNG/0090
LNBWB/RUNG/0091
LNBWB/ILE/0092
LNBWB/LUDE/0176
LNBWB/LUDE/0196
LNBWB/MAKE/0197
0.25
29-Sep-12
LNBWB/MAKE/0198
Mambwe , Mpanda
Vlg/mwakaleli
Rumakali, Rumakali
village
Tanga, Maguu Village
Mkingazi, Mdunduwalo
village
Ruhila River/
Mdunduwalo village
Suma , Busona village
Kasyabone, Igembe rv)/
Kabembe village
Rumakali River,
Bulongwa village
Ikonda river
784324624
P.O.BOX 68 Tukuyu
0.70
10-May-11
LNBWB/RUNG/0205
784772213
222
7-Nov-2011
LNBWB/MAKE/0207
756914438
252602162
P.O.BOX 215
Mafinga
Box 76 Mbinga
Box Peramiho
0.15
0.34
19-Dec-11
22-Dec-11
LNBWB/MBIN/0238
LNBWB/MBIN/0258
252602162
Box Peramiho
0.34
22-Dec-11
LNBWB/MBIN/0259
252552212
Box 700 Tukuyu
Box 170 Tukuyu
0.65
0.25
7-Sep-10
10-Oct-10
LNBWB/RUNG/0004
LNBWB/RUNG/0018
784457884
Box 42
0.10
23-Nov-10
LNBWB/MAKE/0052
252411611
Box 700 Njombe
0.30
16-Jun-11
LNBWB/MAKE/0108
754458126
784358098
784358099
Postal Address
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 28
22
Consolata Hospital - Ikonda
23
Consolata Hospital - Ikonda
24
Tandala Diaconical center
25
Ludilu parish of the ELCT-SCD
26
Diocese/Njombe - Kissinga Mission
27
Makete power service limited
28
Makete power service limited
29
30
African Benedictines of Hanga
William Daniel Kyanda
31
32
33
Archdiocese of Songea
Archdiocese of Songea
Catholic Diocese of Njombe
34
CATHOLIC DIOCESE OF NJOMBE
35
Ilundo Community Society
36
Ilundo Community Society
37
Ludewa Capacity Building Association
39
St.Alois Gonzaga
40
Bugema Micro
Tandala river/ Ikonda
Tandala
Ibande river/ IkondaTandala
Ijangala river/ Masisiwe
village
Salala river/ Ludilu
village
Siwe stream/ Kisinga
village
Idetele stream/
Usagatikwa and
iledevelo
Idetele stream/
Usagatikwa and
iledevelo
Hanga river
Askofu River/ Paradiso
vllage
Lingatunda River 1
Lingatunda River 2
RUHUHU RIVER -1/
Mbugani village
RUHUHU RIVER -2/
Mbugani village
Nyelele River/ Ilundo
Village
Kipoke River/ Ilundo
Village
Lulange River/ Ludende
Village
Luwaita River/ Luwaita
village
Mbaka River/ Busoka
Village
752411611
Box 700 Njombe
0.25
16-Jun-11
LNBWB/MAKE/0109
752411611
Box 700 Njombe
0.28
16-Jun-11
LNBWB/MAKE/0111
767680337
Box 35 Tandala
0.50
16-Jun-11
LNBWB/MAKE/0117
763811974
Box 112 Njombe
0.12
1-Jul-11
LNBWB/MAKE/0118
Box 54 Njombe
0.25
27-Jul-11
LNBWB/MAKE/0130
784358098
P.O.BOX 20128
Makete
0.28
29-Sep-11
LNBWB/MAKE/0197
784358099
P.O.BOX 20128
Makete
0.25
29-Sep-12
LNBWB/MAKE/0198
754565909
Box 217 Songea
MBINGA
0.35
0.15
1-Oct-10
12-Mar-12
LNBWB/SONGE/0166
LNBWB/MBIN/0172
026-2782033
Box 150 Songea
Box 150 Songea
Box 54 Njombe
0.80
0.75
16.00
10-Dec-11
10-Dec-11
3-Apr-12
LNBWB/SONGE/0280
LNBWB/SONGE/0281
LNBWB/NJO/0282
026-2782033
Box 54 Njombe
16.00
3-Apr-12
LNBWB/NJO/0283
Box 480
Rungwe/77228 Dsm
Box 480
Rungwe/77228 Dsm
Box 126 Ludewa Njombe
Box 74 Mbinga
0.25
24-Jul-12
LNBWB/RUNG/0
0.25
24-Jul-12
LNBWB/RUNG/0
0.25
24-Jul-12
LNBWB/LUDE/0
0.25
24-Sep-12
LNBWB/MBIN/0292
0.08
???
754295881
754295881
754054840
763874129
290
TOTAL
Hydropower Report - Preparation of an Integrated Water Resources Management and
Development Plan for the Lake Nyasa Basin (May 2013)
Page 29