Preparations Going Ahead to Meet The Water Needs of The Lesotho Lowlands - Civil Engineering , October 2009

The construction of the US$60 million Metolong dam, some 35 kms outside Lesotho’s capital Maseru, is being welcomed by people in the city and other communities in the region who will gain access to clean and safe drinking water when construction is completed in 2013.  In all, around 1 million people will benefit from the Lowlands water scheme.

Water is one of Lesotho’s few natural resources and the country has made significant advances in ensuring sustainable access to safe drinking water for its people.  Of 24 African countries sampled between 1995 and 2005, Lesotho was ranked third behind Uganda and Ethiopia with regard to the success rate of improving the levels of service of water supply to its population, from informal untreated sources to formal water supply systems.

The Lowland area of Lesotho, which includes the more populous, less mountainous western and southern third of the country, suffers severe water shortages and most of  the raw water for treatment and supply to the capital city, Maseru, is currently derived from an intake on the Mohokare (Caledon) River, but this source is unreliable and of inferior quality.

The population of Maseru has grown by about 5% per year between 1996 and 2006 (from approximately 150 000 to more than 250 000 people), and continues to grow as people are drawn by employment prospects in the garment sector which has burgeoned after benefiting from the USA’s African Growth and Opportunity Act (AGOA).  This has resulted in over 50 firms employing more that 50 000 people, mainly in the Maseru area.  As a result, the availability and reliability of water and wastewater service has become vitally important, and the government has set the supply of plentiful and reliable water to “wet industry zones” as a high priority.

Water Feasibility Study
Te secure a potable water supply, the Government of Lesotho commissioned the Lesotho Lowlands Water Supply Feasibility Study to assess the water needs for domestic, industrial and agricultural use in the districts of Maseru, Berea, Leribe, Butha-Bethe, Mafeteng, Mohales’ Hoek and Quthing.

The study was commissioned by the Lesotho Ministry of Natural Resources, through its Commissioner of Water, and the Lesotho Ministry of Finance and Planning, and funded by the European Development Fund (EDF) and the European Union (EU).

A British company, Parkman, was appointed in 2003 to undertake the feasibility study of various water supply infrastructure options to implement the provision of bulk potable water in the Lesotho Lowlands.  Parkman appointed Andy Pepperell, from the South African consulting engineering firm Jeffares & Green, as their project manager and team leader.  Parkman and Jeffares & Green had worked together previously, as Jeffares Green Parkman, on the BoTT (Build, Operate, Train and Transfer) project that brought potable water to some 60 million people in KwaZulu-Natal.

The earth science consultancy Terratest was appointed to undertake the detailed geotechnical investigation of three dam sites.  This was after some 15 potential dam sites had been investigated by the study team.

A full environmental and social impact assessment with extensive public consultation was undertaken by locally based Sechaba Consultants.

Towards the end of 2004, after 20 months of intense work by a team of 23 experts and support staff, a seven-volume, 1 200-page final feasibility report was published and delivered to the Lesotho Ministry of Natural Resources and the EU.

The report covered everything a national water master plan would require:

In all some 18 potential river sources and dam sites were investigated, as well as groundwater sources, and the study recommended that conjunctive usage of run-of-river, dams, and in  some cases, groundwater sources, be used to ensure the reliability and sustainability of water supplies in the longer term.

The report also recommended that the Lowlands area be supplied from several regional sources such that six separate water supply schemes would result, also allowing for staged construction to enable investment in water supply infrastructure to keep in line with economic growth.

Further, the report identified a long-term solution for bulk supply to Maseru and the peri-urban areas, to be the Metolong Dam on the Phuthiatsana River, some 35 km from Maseru.  The establishment of river-extraction systems to serve the remaining parts of the Lowlands was also recommended.

Bulk Water Supply - Detailed Design Project
On the basis of the feasibility study, the Lesotho government obtained further funding from the EDF (EU) to undertake the detail design and tender documentation phase.

An international competitive bidding process ensued and the tender was awarded to the Lowlands Water Joint Venture (LWJV).  Jeffares & Green was part of this international joint-venture team which comprised SSI Engineers and Environmental Consultants (with input from its Dutch parent company DHV), German-based Fichtner and Lesotho-based GWC Consulting Engineers.

The 18-month project included reviewing water demands in the area, reviewing the flood and yield hydrology of river sources, confirming water demand and projected water requirements, conducting geotechnical and environmental surveys and consulting with public interests groups, as well as undertaking the detailed design and producing tender drawings and tender documents.

For the purpose of the study the Lowlands had been divided into eight demand zones, with a zone depicting an urban centre and village clusters en route having a population of 2 500 and more.  For operation and management purposes, the original eight supply zones were grouped into five bulk water-supply areas served by several “command” and distribution reservoirs placed strategically.  The work to be constructed will comprise some 52 pumping stations and 138 bulk treated water storage reservoirs for the eight different zones.  The reason for the high number of reservoirs is that a number of smaller pumping stations have been positioned to boost water supply to more remote areas at the end of the main bulk water systems, which operate mainly under gravity flow.  The largest of the reservoirs, which will service urban areas, range in capacity from 10 000 m to 25 000 m, while other large reservoirs are typically somewhere between 1 000 m to 5 000 m in volume.  These large reservoirs are reinforced concrete structures and the remaining small reservoirs are pressed steel plate tanks.

The reservoirs and the length of distribution pipeline in each area are:

The value of the works designed for this project was estimated to be in the region of R6 033 million.

Metolong Advance Infrastructure Phase 2 Project
At this point the members of the above joint venture restructured to include a sub-consultant, PHA, which is a Lesotho-based town planning and architectural firm led by Dr Peter Hancock OBE, and bade farewell to the German firm, Fichtner.  The new Lowlands Waterworks Joint Venture (LWJV) was born.  The project director and team leader positions were both filled by Jeffares & Green staff – Andy Pepperell and Roshan Roopchund respectively.

This new joint venture has participated in competitive tendering for several of the major water supply projects being implemented by the Government of Lesotho and funded by a number of agencies, including the Millennium Challenge Corporation (USA), the World Bank, a consortium of Arab Banks, the EU, the Government of South Africa, and the Government of Lesotho itself.

In 2008, the LWJV was awarded a contract to prepare Design & Construct Tender Documentation for a 75 Mℓ/day water treatment works to treat raw water from the proposed new Metolong Dam, and to supply treated water to Maseru and surrounding smaller towns and villages.  Invitations have recently been issued for Design & Construct contractors to express interest in this project.

Further tenders have been submitted by the LWJV for other consultancy work to be undertaken under the same funding programme, with some success.  On 2 June 2009, Jeffares & Green’s Andy Pepperell, on behalf of LWJV, signed a contract for the Advanced Infrastructure Project Phase 2 with the Metolong Authority.  The Meotlong Authority was formed by the Government to manage and implement the development of some major water supply projects: firstly, the Metolong Dam; secondly, the Metolong water treatment works; and thirdly; the downstream bulk treated water conveyance systems.  The total capital cost of these ventures is estimated at over US$ 300 million.

These projects involve a multitude of other consultancies working in parallel; some are undertaking the Metolong dam design; others undertaking social and environmental impact assessments and management plans; and several others will undertake mitigation and benefication projects such as a 25-village WATSAN improvement programme, a 34- village electrification programme in the areas surrounding the dam and the location of the water treatment works.

The objective of the Advanced Infrastructure Project Phase 2 is to implement vital infrastructure ahead of the main water treatment works, dam and downstream conveyance system contractors, thereby ensuring that the tight implementation programme is achieved.  Phase 1 of this project, undertaken by other consultants and contractors, included the construction of a tarred access road from Maseru to the site, the provision of a 33kV powerline and 10 MW transformers to the site, and the construction of a small water supply package plant at the site to provide a temporary water supply.

The infrastructure to be constructed under this new, Phase 2, contract will include planning, design and construction supervision of extensions to the existing main access road, a visitors’ centre, a commercial centre development area, contractors’ construction camps, permanent housing for operational staff, reticulation of the water supply, power and sewerage reticulation, telecommunications systems, a wastewater treatment plant, solid waste management, improvements to local rural access roads, a pedestrian footbridge and a vehicle bridge across the inundated area of the dam, as well as the refurbishment of some police stations, clinics and post offices.

These engineering services will be supported by a programme of geotechnical investigations, land surveys and the preparation by an EIA team of an Environmental Management Plans for all aspects of the works.  The design phase of the LWJV contract will be completed within 5 months.  Thereafter, construction supervision during the implementation phase will take a further 12 months.

The estimated cost of these works is some US$30 million.  The works will be constructed in stages with various priorities.  The elements with the highest priority will be ready by mid-2010 to facilitate the smooth establishment of the dam, the water treatment works and thedownstream conveyance systems.


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