Artigos

Structural works to combat the effects of drought in southern Angola

www.cedesa.pt

1-Introduction: characterization of the water catchment construction project on the Cunene River

It has been our concern to seek concrete answers to specific problems, in addition to the intense rhetoric in pre-election periods. In this case, one of the topics that interests us is the drought in southern Angola. As we mentioned in a report from last November[1], we follow the works in progress related to the Drought. One of them is almost ready to be inaugurated and operational. It is about that project we give an account in this document.

This report focuses on the execution of the Structuring Works to Combat Drought, specifically the design and construction of a catchment on the Cunene River and the construction of pipelines to the localities of Cuamato, Namacunde and Ndombondola.

This project has 2 Lots:

• LOT 1 – Design and Construction of Intake on the Cunene River, Pumping System, Pressurized Duct, Open Channel from Cafú to Cuamato and 10 Chimpacas (water reservoirs);

• LOT 2 – Design and Construction of Adductor Channel from Ombala – Cuamato to Ndombondola, Adductor Channel from Cuamato to Namacunde and 20 Chimpacas.

Regarding Lot 1, the General Contractor is SINOHYDRO Corporation Limited, a limited company incorporated in 2011 in Luanda whose property is held by Chinese companies. The supervision is carried out by the Consortium GWIC – Angola, S.A / SINTEC – Consultoria de Engenharia, Lda. As for Lot 2, the responsible entity is the same, except for inspection; in this case the responsible entity is TRIEDE Angola, Lda. A prestigious company from Portugal.

The deadline for the project conclusion points to the end of March 2022. Therefore, a very brief opening is expected.

The value of the two works reaches 140 million US dollars.

Fig. 1: Lots 1 and 2 of the Project (Cunene Province, Angola)

2- Projects explanation

Lot 1 comprises the water transfer works from the Cunene River, in the Cafu section, to the localities of Cuamato, and is based on the construction of the water intake, pumping station, pressurized pipelines, feeder channels and associated facilities.

The Project consists of the following main elements:

• Intake from the Cunene river bed, including the water intake structure, floodgates, grates and other associated equipment;

• Pumping Station with a capacity of 2 m3/s;

• The Pumping Station will be equipped with two active pumps and one backup pump in the first phase. The pumps will be turbine-type, vertical, with a nominal capacity of 1 m3/s;

• Gravity channel coated to receive 6 m3/s. The length of the channel is 46.54 kilometers with connection to the reservoir, considering the alignment that minimizes earth movements;

• A North-South alignment was established from Cafu to the Ombala-Io-Mungo region. In the end, the gravity channel will be divided into two branches, serving the localities of Namacunde and Ndombondola.

Fig. 2: General Conductor Channel | Manual cladding with concrete class C20/25, 35 km, 1 front km (45,954)

Fig. 3: Chimpacas | State of the Chimpaca

In turn, Lot 2 comprises the works of the following channels, which derive from the Bypass Structure (BS) of flows from the General Conductor Channel (GCC):

• West Conductor Channel – WCC (Cuamato / Ndombondola), with a length of around 53.04 kilometres;

• East Conductor Channel – ECC (Cuamato / Namacunde), with a length of about 53.11 kilometres.

Fig. 4: East Adductor Channel (EAC)

Fig. 5: Placing the fence on the Chimpacas of the East and West channels

3-Delays, advances and resources used

Due to several constraints that occurred in 2021, such as lack of diesel in the south of Angola, water for concrete production and respective curing, cement at work, and rainfall, the completion of the work slipped a little, since completion was initially scheduled for February. Now the completion date is for the end of March (maybe early April).

A total of 1250 workers (Lot 1 – 417; Lot 2 – 833) were assigned to the works, 162 (Lot 1 – 70; Lot 2 – 92) of Chinese nationality and 1088 (Lot 1 – 347; Lot 2 – 741) of Angolan nationality. Equipment is allocated to the works, in a total of 388 units, of which 135 in Lot 1 and 243 units in Lot 2.

4-Benefits for the population

The project, as presented above, consists of the construction of the water transfer system for the Cunene River, from the locality of Cafu to the Chanas region in the province of Cunene, in Angola. The interventions are included in a total investment of more than €140 million made by the government to deal with long periods of drought that dramatically affect people and animals.

The aim is to create the right conditions for the development of agriculture and livestock, increasing resilience to climate change in this practically deserted region of southern Angola, subject to frequent prolonged droughts, benefiting hundreds of thousands of inhabitants and livestock, as well as providing water for irrigation in an area estimated at 5,000 hectares.

The project is expected to benefit approximately 200,000 inhabitants and 250,000 head of cattle. It should be noted that Cunene has about 900 thousand inhabitants, therefore more than 20% of the population is covered by this work.


[1] https://www.cedesa.pt/2021/11/16/o-combate-estrutural-a-seca-no-sul-de-angola-o-caso-do-cunene/

Structural combat against drought in southern Angola: the case of Cunene

The drought in Cunene

The drought in southern Angola is a phenomenon that plagues the region over and over again, causing hunger among broad strata of the population.

As of the end of 2020, the region faced the worst drought in 40 years. According to the spokesman for the World Food Program (WFP) Tomson Phiri, “the country has been experiencing a period of drought since last December, with rainfall below average”[1].

This scenario, which has been repeated, and will likely worsen due to global warming, as the World Bank warns, writing that, “natural hazards in the form of floods, erosion, droughts and epidemics (…) prevent development and are expected to worsen as the climate changes”[2], implies a structuring intervention by public authorities.

The objective of this study is to investigate the structural measures that the Angolan government is developing to present sustainable solutions to the drought problem. We focus on the province of Cunene located in the southern interior of Angola, which has been one of the most affected by drought.

In fact, since Angola became independent, it is only recently that the problem of drought has been taken more seriously by the authorities. Before these projects, the situation was somehow alleviated with water holes, however the suffering of the population remained or gradually worsened. The provincial governor of Cunene, Gerdina Didalelwa, on one occasion confessed that “these drillings have been done empirically and are only spending money”[3]. In other words, drillings can even be carried out, but only when there is professionalism behind it; only after an in-depth study was carried out by companies that have technical skills and a thorough knowledge of the waters.

Structuring projects

In mid-2021, the Angolan government announced the planning and execution of several projects in the province of Cunene, which aim to structurally combat the chronic drought that ravages the south of the country.

Project 1

The first of the projects we are going to mention is the construction of the water transfer system for the Cunene River, starting from the Cafu region.

This project is divided into two batches, the first of which aims to build a pumping system in the Cunene River, pressurized pipeline, open channel from the locality of Cafu to Cuamato and 10 chimpacas[4] (water reservoirs).

With regard to the second batch, the purpose is to build two water channels, from Cuamato, one (west conductor) going to Ndombondola, with 55 kilometers and the other (east conductor) to the municipality of Namacunde with 53 kilometers[5]

The construction work are being carried out by the company Sinohydro Angola, with an estimated budget of more than 44 billion kwanzas, if we include the two batches.

The start of the execution of this project has already taken place and counts on an environmental pact study that includes a protocol of the Southern African Development Community (SADC), as well as the sharing of information with Namibia.

The Cafu project is expected to be completed in the first quarter of next year, and it will benefit approximately 200,000 inhabitants and 250,000 head of cattle.

Project 2

The second project that deserves mention is the construction of the Calucuve dam, located in the municipality of Cuvelai. This earthen dam is 19 meters high and has a storage volume of 100 million m3 of water.

The project’s budget is around 177 million dollars, with the company Omatapalo-Mota-Engil as the responsible contractor, and the construction period is 20 months.

The main purpose of the construction of this work is to supply water to the populations, and it is planned to satisfy the needs of more than 80,000 people, as well as meet the needs of approximately 182,000 heads of cattle.

On the other slopes, it will supply water that will allow irrigation throughout the year in an area estimated at 2,600 ha.;

It will ensure the sustainability of economic and social activities in the project area. It will reduce the problem of seasonal water scarcity in the northwestern part of the Cuvelai basin. And finally, to mitigate or prevent damage caused by floods to assets and activities in the local economy in cities located downstream of the dam (Cuvelai Delta area – Evale).

The lead time is 20 months.

Project 3

As for the third project, the construction of the Ndué dam, it is an undertaking also led by Synohidro Angola, with a construction period of 30 months, and an estimated budget of around 192 million dollars.

It will be a 26 m high earthen dam with a storage volume of 145 million m3 of water, on the Caúndo River upstream of the Ndué.

The main purposes of this project aim to satisfy the domestic needs of approximately 55,000 people, as well as to guarantee the quality of water supply to the population. In addition, it aims to satisfy the needs of approximately 60,000 heads of cattle.

Other equally essential goals are also highlighted, such as:

Provide water to allow year-round irrigation of an estimated 9,200 ha area and ensure the sustainability of economic and social activities in the project area and reduce the problem of water scarcity in the central area of ​​the Cuvelai basin.

Finally, the dam could become an important source of water supply for the province of Cunene.

The execution period is 30 months.

***

A final note also for the recovery of existing dikes and weirs in the municipality of Curoca, which is 334 kilometers from the city of Ondjiva[6].

Table 1- General quantifiable benefits of construction work against drought in Cunene

ProjectsPopulationCattleValue
Project 1200.000250.00044 M USD
Project 280.000182.000177 M USD
Project 355.00060.000192 M USD
TOTAL335.000492.000413 M USD

It appears that in addition to providing irrigation and providing increased possibilities for water distribution, these works will directly benefit 335,000 people and 492,000 heads of cattle, costing around 400 million dollars.

Portuguese participation

The Portuguese participation in these important construction work is relevant. Mota-Engil has a relevant stake (50%) in the consortium that builds the Calucuve dam (Project 1), having won the respective tender. COBA, also based in Portugal, is the supervisor of the Ndúe dam (Project 3). There is thus a significant intervention of Portuguese engineering in these structural projects.

Over the past two years, Mota-Engil has undergone a vigorous restructuring that has been reflected not only in Portugal, but also in Mozambique and Angola. It should be remembered that in mid-2020, the company established a partnership with the Chinese CCCC, which defines its participation of more than 30% in the construction company controlled by the António Mota family[7].

Shortly thereafter, Mota-Engil obtained a contract in partnership for road rehabilitation and construction in the Lundas with its subsidiary, with a value of around 280 million euros. On that occasion, the company underlined that it would reinforce its order book in the market, seeking to maximize the use of the assets that the group has in the country.


[1] https://www.rfi.fr/br/%C3%A1frica/20210326-onu-alerta-sobre-fome-causada-pela-pior-seca-em-angola-em-40-anos

[2] https://climateknowledgeportal.worldbank.org/country/angola

[3] https://www.jornaldeangola.ao/ao/noticias/consequencias-da-seca-no-cunene-com-dias-contados/

[4] https://www.angop.ao/noticias/entrevistas/construcao-da-barragem-do-cafu-a-bom-ritmo-manuel-quintino/

[5] Idem

[6] https://www.angop.ao/noticias/sociedade/barragens-de-caluve-e-ndue-vao-beneficiar-136-mil-pessoas/

[7] https://www.jornaldenegocios.pt/empresas/construcao/detalhe/mota-engil-ganha-contrato-de-280-milhoes-em-angola