Songwe

1 : Description of water course

2: Hydrological Description

3: Socio-economic Issues

4: Trans-boundary Issues

5: Cooperative transboundary activities

 

1. Description of Water Resource

 

Figure 1: Map of the Songwe River Basin

1.1. Geographical description

 

1.1.1. Location

The Songwe River forms the border between Malawi and Tanzania and the Songwe Basin lies between latitudes 9°6’23–9°56’17 South and longitudes 32°44’34–33°56’31 East.

1.1.2. Riparian States

The Songwe River Basin is shared by Malawi and Tanzania. 45% of the basin lies in Malawi in the Chitipa and Karonga districts. The remaining 55% lies in Tanzania and spans the following districts: Kyla, Ileje, Mbeya and Mbozi[1]. The table below shows the area of each district occupying the basin.

Table 1: Area distribution per district

Country

District

District Area (km2)

Area (km2) of the district within the Songwe Basin (SB)

Area of district within the SB measured against total SB area (%)

District area measured against area of district within SB (%)

Tanzania

Mbeya

19,098

146.7

3.5

0.77

Mbozi

9,679

627.1

14.9

6.48

Ileje

1,908

1,419.6

33.7

74.40

Kyela

965

105.9

2.5

10.97

Malawi

Karonga

3,335

329.7

7.8

9.88

Chitipa

4,288

1,585.3

37.6

36.97

 

39,927

4,214.3

100

 

Source: Songwe River Transboundary Catchment Management (SRTCMP, 2004:2)

1.1.3. Topography

The total surface area of the Songwe River Basin is estimated at 4,278km2.  The Songwe River originates in Mbozi and Mbeya districts in Tanzania and meanders through the catchment before discharging in Lake Malawi.

The catchment can be divided into three areas: the Upper Catchment, Middle Catchment and Lower Catchment. The Upper Catchment, which straddles the Ileje district in  Tanzania and the Chitipa District in Malawi, is located at 2,000 – 2,400m above sea level, while the Middle Catchment ranges from 1,000 to just over 1,300m above sea level. The Lower Catchment is located at between 500m and 1,000m above sea level.

Figure2_Schematic_LakeMalawi.jpg

Figure 2: Schematic of the three areas of the Songwe Catchment Source: Chafota (2012)[2]

 

2. Hydrological Description

2.1. Rainfall

The mean annual rainfall in the Songwe River Basin is 1,022mm[3]. Disaggregated into the three catchments, the rainfall distribution in the catchment is such that the upper catchment receives 1400 – 2100 mm of rainfall, while the middle and lower catchments receive rainfall in the range 1000 -1300 mm. Under the long-term mean rainfall pattern (30 years), the highest rainfall in the basin occurs between February and May[4] (see figure 2 below).

Table 2: WRA 9 rainfall station summary

WRU

No. of Rain Guages

Monthly Average (mm)

Monthly Maximum (mm)

Annual Average (mm)

9A

12

88.8

468.9

1,065.9

9B

10

91.1

424.7

1,093.4

Average

1,022

 

 

Figure 3: Long-term Mean Monthly Rainfall in Songwe River Basin Source: Chafota, 2012

 

 

The Basin is increasingly prone to droughts and extreme weather events such as flooding. The driest year experienced since 1960 was 1996/97. Whereas prior to 1996 droughts occurred at a frequency of about every 5 years, the interval after 1997 has dropped to every 2 years[5].

Table 3: Driest Years in Songwe River Basin for the period 1960 - 2009

Driest Years in Songwe River Basin for the period 1960 - 2009[6]

Driest year

1996-97

Second Driest Year

1993-94

Third Driest Year

1999-2000

 

2.2 Runoff

The Songwe rises in the Ruwenya Hills (1200-1800 m, with a high point of 2200 m). The majority of the catchment lies in Tanzania (2170 km2 compared to 1890 km2 in Malawi). The main tributaries include the Itumba, joining near Kapenda and the Kaseye rising in the Mafingi mountains on the Malawi-Zambia border. The high Misuku hills, Mugesse and Matipa Forest Reserves are in the middle reaches of the catchment (NWRMP 1986; Government of Malawi, 2011:248[7]). The Songwe generally has a low gradient; for example the Kaseye flows mainly over flat areas at 1200-1300 m of the Chitipa plain, and the Kagoma, Hanga and Ipenza tributaries also have low gradients. The areas around Chitepa and further downstream are very flat (NWRMP 1986; Government of Malawi, 2011:248).

Most of the Lufira catchment is on the high plateau west of the Rift Valley; the Masingi mountains and forest reserve are to the west and the Misuku Hills to the northwest. There are many tributaries; notably the Mbalizi and Kalenje (NWRMP 1986). The river passes through uninhabited forested areas and drops down in elevation from 1400 m to 500 m before flowing through the lakeshore area lying between 450–500 m (ibid).

2.3 Surface Water

The overall yield for WRA 9 which includes the Songwe and Lufira rivers is derived from a long-term assessment of the gauged record at stations 9A2 and 9B7 which represent flows in the Songwe/Lufira Basin. This represents the total available surface water yield from WRA 9 and since it is based upon observed flow data (i.e. not naturalised), it represents the residual actual flow that might be utilised to help meet future demand. The total yield is shown in Table 4.

Table 4: WRA 9 (Songwe Basin), total theoretical surface water yield (Government of Malawi, 2011:255 )

Scenario

Average Residual Available Flow (Ml/d)

Dry Season

1055

Extreme Drought (1991)

758

Wet Season

2834

Annual Average

1944

 

The total sustainable surface water yield for WRA 9 in 2010, is shown in Table 5 below. These are the values derived once the maximum of the EFR or the Minimum Flow has been subtracted from the total yield and they are used for water resources assessment. They represent the total flow available in the WRA to meet future demands for water.

Table 5: WRA 9, total sustainable surface water yield, 2010 (Government of Malawi, 2011:256 )

Scenario

EFR (Ml/d)

Average Sustainable Yield (Ml/d)

Dry Season

614

441

Extreme Drought (1991)

614

240

Wet Season

1351

1483

Annual Average

983

962

 

Surface water demand in Songwe Basin is assessed on the basis of the commercial and institutional sectors in the WRA as well as the main water boards in the area and customers that those water boards supply. The data is summarised in Table 6 (below), in terms of the total commercial demand and the demand for institutional, commercial and non-commercial provision by the Water Boards.

Table 6: Commercial/Institutional water demand summary for WRA 9 (Songwe/Lufira)

 

Government of Malawi (2011:238[8])

The 2020 to 2035 forecast of water use by the commercial and institutional sector in Songwe Basin has been assessed on the basis of an assumed growth rate for each sector. The growth rates used to determine the effect on overall water demand is shown in Table 7.

Table 7: Commercial/Institutional water demand summary for WRA 9, 2020 and 2035

 

Government of Malawi (2011:241[9])

2.4 Ground Water

The hydrogeology of Songwe River Basin (WRA 9) consists of a number of different aquifer types, which are listed in Table 8 below.

Table 8: Songwe River Basin (WRA 9), aquifer type overview (Government of Malawi, 2011:256)

 

With regards to the total potential abstractable yield assessment volume per aquifer type, the resultant values for Songwe River Basin (WRA 9) are shown in Table 9 below.

Table 9: Songwe River Basin (WRA 9), Total potential abstractable volume per aquifer type (Government of Malawi, 2011:260)

 

The total sustainable abstractable yield assessment resultant values for Songwe River Basin (WRA 9) are shown in Figure 4 below with climate change adjustment factors for the forecast values in 2020 and 2035.

 

Figure 4: Songwe River Basin, Total abstractable groundwater volume

Groundwater is available for most uses except large-scale arable agriculture in all aquifer areas on the basis of a ‘fitness for purpose’ assessment conducted by the Government of Malawi in 2011 (see table 10 below).

Table 10: Songwe River Basin, groundwater “fitness for purpose” assessment (Government of Malawi, 2011:261)

 

 

2.5 Water Use

At almost 68% or 22Ml/d, agriculture accounts for the bulk of water used in the Songwe River Basin, with the majority going towards arable agriculture as opposed to livestock farming. Domestic use accounts for the next largest usage, at 8Ml/d. Given the remoteness and rural nature of the Songwe River, the population relies predominantly on borehole water - 12% of total water usage. Piped water makes up a small percentage at 3. 8%.

Table 11: Water demand estimates for Songwe Basin, 2010

Sector

Sub-Sector

Demand (Ml/d)

Demand (%)

Domestic

Piped into dwelling

0,4

1,25

Domestic

Piped into yard/ plot

0,5

1,56

Domestic

Community stand pipe

1,1

3,44

Domestic

Protected well/ BH

3,9

12,19

Domestic

Unimproved source

2,1

6,56

Agriculture

Arable

18,4

57,50

Agriculture

Livestock

3,6

11,25

Commercial

 

0,5

1,56

Institutional

 

0,3

0,94

Mining

 

1,0

3,13

Unaccounted for

 

0,6

1,88

Usable Return

To surface water

6,5

20,31

Usable returns

To groundwater

0,0

 

TOTAL (gross)

39,0

 

TOTAL (net)

32,5

 

 

 

Figure 5: Water Demand Estimate for Songwe Basin (WRA 9), 2010

The demand assessment illustrated in Table 12 below is factored for wet and dry season conditions, to allow for direct comparison with the water supply and yield data. This analysis is based upon a sectoral analysis of demand changes during different wet and dry periods, particularly crop water requirements. The result of this analysis is shown in Table 12 below.

Table 12: Water Demand Estimate for Songwe River Basin- WRA 9 (wet and dry season), 2010

Scenario

Total demand (Ml/d)

Annual average

32

Dry season

45

Wet season

20

Extreme drought *

45

* Insufficient data to determine this value separate from a standard dry season

2.5.1 Climate change

Chafota (2012) observed that the farming and fishing livelihood coping strategies for the Songwe River catchment are affected by climatic variability and inappropriate land use husbandry upstream which results in increased frequency of seasonal flooding. In addition, the floods may result in loss of human life, destruction of crops, livestock and property (Iteco, 2007). The seasonal impacts of floods and continued decline in fish catches suggested, during the Project conception, the need to develop alternative income generating activities (IGA).

3. Socioeconomic Issues

3.1. Demographics

The Songwe River Basin has a population of about 320,000[10] (2008). The population on the Malawi side is 204,016 (indicated in table 13 below).The area is dominated by rural settlements, with the rural poor comprising 80% of the population of the basin. The basin is located in marginal and remote areas of both Malawi and Tanzania[11].

Table 13: Population Statistics for the Songwe River Basin

Population Statistics for the Songwe River Basin in Malawi

 

 

2020 Population

2035 Population

District

2010 Population

Low Growth Scenario

Medium Growth Scenario

High Growth Scenario

Medium Growth Scenario

Chitipa

125,954

167,734

173,904

181,202

282,726

Karonga

78,062

98,694

102,387

106,662

153,870

TOTAL

204,016

266,429

276,291

287,864

436,595

 

3.1.1. Economic sectors active in the basin

The economy of the basin is highly dependent on water related sectors. Its key active economic sectors are arable agriculture, livestock agriculture and mining. Given that the population is largely rural, the majority are engaged in farming. The key economic sectors are briefly outlined below.

Arable agriculture - Songwe River Basin is dominated by large areas for maize crops in both winter (irrigated) and particularly summer (rainfed), but dominated by small scale farmers, rather than large estates (Government of Malawi, 2011:235[12]). Smaller areas for summer (rainfed) crops of rice and tobacco and some much smaller areas of other crops also contribute to arable agriculture in the basin.

Table 14: Proportion of the total area of the different crop types that are irrigated in Songwe Basin 2010 (WRA 9), and areas farmed (ha)

Proportion of the total area of the different crop types that are irrigated in Songwe Basin

Total Areas farmed (units in ha)

Crop

Summer

Estate

Winter

Summer

Estate

Winter

Maize

1%

0%

5%

22,072

-

2,577

Rice

10%

-

100%

2 ,926

-

299

Tobacco

5%

-

-

2 ,986

-

-

Cotton

5%

0%

-

246

-

-

Wheat

25%

-

25%

144

-

68

Coffee

1%

 

-

549

-

-

Sugarcane

0%

 

0%

-

-

-

Tea

-

 

-

-

-

-

Government of Malawi (2011:37)[13]

Livestock agriculture - Livestock agriculture in the basin is dominated by small scale chicken and goat farming, supported by smaller numbers of cattle. Sheep and pig farming do form a small part of the economic baseline, but are not nearly as extensive as other livestock. The source of water for livestock agriculture in the basin is primarily surface water, however, its use is very limited owing to the small-scale nature of the operations. The table below shows the livestock population in the Songwe Basin by district.

Table 15: Livestock Agriculture summary for Songwe Basin (Government of Malawi, 2011:238 )

 

Mining - The mining sector in Songwe River Basin (WRA 9) is assessed on the basis of the main mineral extractions known within the WRA as illustrated in table 11 below.

Table 16: Mineral extraction and mining summary for WRA 9 (Songwe/Lufira Basin)

 

Source: Ministry of Development Planning and Cooperation (2010). Annual Economic Report 2010. Budget Document No. 2.

4. Transboundary Issues

4.1. Defining the border

The Songwe River forms part of the international boundary between Tanzania and Malawi with the boundary line between the two countries demarcated as the deepest channel of the Songwe. However, frequent shifting of the international border between the two countries in the river delta zone due to the random meandering of the river presents a transboundary challenge. Movement of the river occurs principally across its delta before discharging into Lake Malawi/Nyasa at peak flow periods during the rainy seasons. The length of the meandering portion of the channel is 29 km. Upstream the changes in river channel at times extend to 150m but in the downstream part of the meandering section changes can be quite drastic with shifts of up to 2.5 km.

4.2. Inadequate infrastructure

Infrastructure damage and loss of life occur in times of heavy rains; the road network is particularly poor and the use of unsafe life-threatening monkey bridges to cross the river is common. In addition, there is considerable unused hydropower development potential that could contribute to economic growth and alleviation of the severe electricity shortages facing the two countries. Over 75% of the population of the Basin has no access to electricity. An opportunity for joint infrastructural development exists which is being exploited jointly through the Songwe River Basin Development Plan.

5. Cooperative transboundary activities

In 2004, a Memorandum of Understanding (MoU) was signed between the riparian governments of Malawi and Tanzania to establish a Songwe River Basin Development Programme (SRBDP).  The MoU states that the development objective is to “improve the social and economic welfare of the people living in and around the Songwe River Basin and the two nations as a whole.” The Programme has been funded since 2010 by the African Water Facility of the African Development Bank and NEPAD IPPF.  The core components of the Programme include:

  • Preparation of a shared vision towards 2050 and a 10-year Songwe River Basin Development Plan;
  • Detailed design and preparation of priority investments in the Lower Dam and associated hydropower plants, irrigation schemes, river stabilization works, flood control, and water supply;
  • Environmental and social safeguarding; and
  • Creation of a Songwe River Basin Authority and associated integrated water resource management capacity building at various levels and stakeholder engagement.

The project is expected to be completed in 2021. 

5.1      Songwe River Basin Commission and Agreement

As noted above, under the Songwe River Basin Development Programme (SRBDP), there have been ongoing efforts to clarify the location of the border (which often changes as the River is subject to seasonal meandering), and to define shared roles and responsibilities of the two riparians in the planning, management and development of the Songwe Basin.

To facilitate this process, the two countries are in the process of finalizing a Convention on the Establishment of a Joint Songwe River Basin Commission. It states that the Parties shall cooperate pursuant to the provisions of the Convention and through the Commission as the institutional mechanism for joint management and development of the shared resource.  The Principles guiding the Commission include:

  • Cooperation on the basis of sovereign equality and territorial integrity;
  • Sustainable development and equitable and reasonable utilization of the common water resources, including the Songwe and its tributaries;
  • Precaution and prevention of significant harm; and
  • Equitable and reasonable sharing of roles and responsibilities as well as benefits.

 

While this list appears to refer to many of the core principles of international water law (and those that are mandated under the SADC Protocol), it also emphasizes “sovereign equality and territorial integrity.”  Since the principle of absolute territorial integrity in international water law has long been discredited in favour of one of equitable and reasonable utilization, it may be that the Convention is referring to limited territorial sovereignty, in conjunction with the principle of equitable and reasonable use, particularly in the light of the SADC Protocol – with its clear emphasis on equitable and reasonable use and development.

The Commission itself is to consist of a Council, a Joint Steering Committee and a Secretariat.  The Commission is meant to:

  • Assist in gathering and processing of information;
  • Provide advice to the parties;
  • Form committees and task forces to address issues related to the shared watercourse;
  • Appoint consultants and contractors to assist with implementation; and
  • Prepare and adopt its rules of procedure.

 

The Council is to consist of no more than six permanent members and additional advisors and each delegation shall consist of the Minister or Deputy Minister from the Ministries responsible for water, lands, energy, irrigated agriculture, and local government.  There are to be two co-chairs, one from each Party.  The Council is meant to:

  • Provide oversight for the Commission;
  • Establish policies and provide guidance regarding joint activities;
  • Receive and address work plans, approve rules and regulations, and approve the budget; and
  • Oversee dispute resolution among the Parties.

 

Notably, there are references to the need for policies, decisions and other guidance to “support cooperation and coordination in joint activities and projects in a constructive and mutually beneficial manner for the sustainable development, utilization, conservation and management of the Songwe River Basin and related resources, and protection of the environment and aquatic conditions in the Basin…”  This appears to elaborate on the principle of sustainable development that is included under the general mandate of the Commission and expands its focus on environmental protection.

The Joint Steering Committee shall have five members from each Party at no less than Head of Department level.  The Steering Committee is meant to, inter alia:

  • Implement policies and decisions of the Council and other tasks as assigned;
  • Where appropriate assist in harmonization of policies, strategies and legislation, institutional frameworks and plans for management;
  • Form development programs and project for Council approval;
  • Coordinate with development partners;
  • Provide oversight on construction and maintenance of infrastructure under SRBDP; and
  • Conduct studies and assessments for the protection of the environment and maintenance of ecological balance in the Basin.

 

The Secretariat is to be headed by a Chief Executive Secretary with a five-year term, appointed by the Steering Committee and approved by the Council.  The Secretariat is meant to:

  • Carry out Council decisions under direction of the Joint Steering Committee;
  • Provide management and technical services and financial administration and advice;
  • Prepare work plans, programs and reports as required;
  • Form and implement an annual work plan;
  • Maintain and disseminate data on hydrology and water quality, and the aquatic environment;
  • Manage on a daily basis the construction, operation and maintenance of the infrastructure under the SRBDP; and
  • Provide secretarial services for the Council and Committee.

 

The Parties are subject to two obligations: (1) supply information and plans relating to the development and use of the resources of the Basin as required by the Commission; and (2) provide members to the Commission and competent consultants as required.

Disputes between the Parties are to be resolved amicably, through diplomatic channels.  If Parties are unable to reach agreement, they shall appoint a third party mediator agreed on by both.  Should that fail, the Parties are to refer the dispute to the SADC Tribunal

Relevant Documents

  • Lake Malawi Technical Brief
 
 

[1] Chafota, J (2012) Integrated Natural Resources Management in A Dynamic Transboundary Watershed Context: The Songwe River Catchment Experience.

[2] Chafota, J (2012). Integrated Natural Resources Management in a Dynamic Transboundary Watershed Context: Songwe River Catchment Experience.

[3] Government of Malawi, 2011. Malawi Water Resource Investment Strategy Report, Annex II – Surface Water.

[4] Source: Chafota, J (2012). Integrated Natural Resources Management in a Dynamic Transboundary Watershed Context: Songwe River Catchment Experience.

[5] Source: Chafota, J (2012). Integrated Natural Resources Management in a Dynamic Transboundary Watershed Context: Songwe River Catchment Experience.

[6] Government of Malawi, 2011. Malawi Water Resource Investment Strategy Report, Annex I(ii) – Water Resources Assessment for WRAs 5-10.

[7] Government of Malawi, 2011. Malawi Water Resource Investment Strategy Report, Annex I (ii) – Water Resources Assessment for WRAs 5–10

[8] Government of Malawi 2011 Malawi Water Resource Investment Strategy Report, Annex I(ii) – Water Resources Assessment for WRAs 5–10.

[9] Government of Malawi 2011 Malawi Water Resource Investment Strategy Report, Annex I(ii) – Water Resources Assessment for WRAs 5–10.

[10] AfDB: Songwe River Basin Development Project Appraisal Report

[11] Source: Chafota, J (2012). Integrated Natural Resources Management in a Dynamic Transboundary Watershed Context: Songwe River Catchment Experience

[12] Government of Malawi, 2011. Malawi Water Resource Investment Strategy Report, Annex I(ii) – Water Resources Assessment for WRAs 5-10

[13] Government of Malawi 2011 Malawi Water Resource Investment Strategy Report, Annex I(ii) – Water Resources Assessment for WRAs 5–10.