Environmental Impact

Infrastructure projects of the magnitude of Phase II are informed by extensive research in order to fully understand and mitigate the impact of the project's implementation on the community and the natural environment in the area. Prior to the impoundment and flooding of the area upstream of the Polihali Dam, the LHDA required an informed and considered baseline assessment of the existing biological, including cultural, and social environment. These baseline studies were related to water quality, flow and geomorphology, the socio-economic conditions, fauna and flora, archaeology and public health.

The data collected in the Phase II baseline studies serve as a reference against which future changes can be measured in line with internationally recognised standards. LHDA appointed a number of consultants to undertake the baseline studies. The main objectives of these studies were to:

  • Establish the existing biological and social baseline conditions within the project area;
  • Provide a pre-project reference against which future changes can be measured in line with internationally recognised standards; and
  • Provide input into detailed Environmental and Social Impact Assessment(s) (ESIAs) that will be undertaken for project components in the project area.
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Socio-Economic Baseline Study

Affected communities receive annual compensation. In this photo, one family receives grain and beans.
The study aimed to gain an understanding of livelihoods and quality of life of people in the project area. The study was made up of the following tasks:
  • A comprehensive household survey of:
    (a) all households resident in the local Polihali catchment area as defined by LHDA excluding Mokhotlong Town where a sample of households was interviewed ;
    (b) households located in three control areas outside the local catchment area; and
    (c) households living within a five kilometre buffer zone of the Senqu River between its confluence with the Malibamatso River and the Polihali Dam.
  • A monthly income and expenditure survey of a sample of households in the local catchment; and
  • A baseline survey of community-level variables by means of interviews with local authorities and focus group discussion.

Flow, Water Quality and Geomorphology and IFR Baseline Study

View of measuring weir looking upstream from the right bank. The weir is downstream of Polihali Dam Site.
The aim of the study was to determine the volume (magnitude), frequency, timing and duration of water flows that need to remain in the downstream river following the construction of the Polihali Dam. This is to afford suitable protection to the river ecosystem and to ensure the long-term and sustainable availability of the ecosystem services on which the downstream communities depend. This study comprised the following tasks:
  • Establishment of the baseline for river flows, water quality and geomorphology within the catchment of the Polihali Dam;
  • Collection of Instream Flow Requirements (IFR) baseline data for socio-economic, fish, river condition and riparian woody vegetation downstream of the Polihali Dam;
  • Determination of the objectives for IFR based on the present river conditions and the delivery of water from the Senqu catchment to South Africa;
  • Development of a model that will predict the change in the baseline conditions in the Senqu River below the proposed dam for various release scenarios;
  • A flow-release strategy to achieve the stated objectives;
  • The design of a long-term monitoring programme to monitor the effects of the IFR releases. The IFR can be modified if the monitoring data indicate that the effects are more adverse than have been predicted; and
  • The design of a system to determine resource losses and mitigation.

Biological and Archaeological (including Heritage) Baseline Study

White storks (Ciconia ciconia) occur in Senqu valley
This study sought to identify potential impacts on the biota and archaeological (including heritage) aspects arising from Phase II and to provide appropriate management measures, as well as a monitoring plan. It included the following tasks:
  • A baseline vegetation survey that included habitat and vegetation classification; identified sites of high conservation value; produced inventories of important plants; and the development of a long-term monitoring programme;
  • A baseline fish survey that established a list of the fish species present; the conservation status of each species; numbers of each species; age and sex structure of each species; sensitivity of each species to the various elements of the proposed project; the sensitivity of particular species to invasive and alien species; and the development of a long-term monitoring programme;
  • A baseline faunal survey that established a list of the species of birds, mammals, reptiles and amphibians that are likely to occur within the dam basin; identified key species (and indicator species) that are to be monitored both during and post construction; and
  • An archaeological (including heritage) baseline survey that includes an inventory and description of the condition and importance of all archaeological sites in the inundation area. The study included proposed mitigation measures that include excavation and removal of artefacts.

Procurement update – Environmental and Social Impact Assessments

The status on the Requests for Proposals for the Environmental and Social Impact Assessments, is as follows:

Contract 6004: The ESIA for the Polihali Western Access Corridor (PWAC) comprising the Polihali Western Access Road (PWAR), including quarries, borrow pits, bulk power supply and telecommunications infrastructure, was awarded to Environmental Resources Management (Pty Ltd) Southern Africa and a Lesotho-based sub-consultant, Sechaba Consultants. The contract, which commenced in September 2016, will take approximately 12 months to complete.

Contract 6014: The ESIA for the Polihali Reservoir and Associated Infrastructure. The main objective of this assignment is to undertake an ESIA for the Polihali Dam, Saddle Dam and Reservoir; Quarries and Borrow Pits; Eastern Transfer Tunnel; Major Bridges; and Project Housing and Site Establishment components that meets the requirements of the Environment Act No. 10 of 2008, the Environmental Impact Assessment (EIA) Guidelines (2009), and other relevant national legislation. The 14-month contract was awarded to Environmental Resources Management (Pty Ltd) Southern Africa in July 2016.

Contract 6016 : ESIA for Western (Katse) Site Facilities. The ESIA relates to the bulk utilities supplied under the Advance Infrastructure contracts and the construction and establishment of labour camps and works areas on the Katse/Matsoku (Western) side. The procurement of a consultant for the ESIA is underway.

Contract 6025: Cultural Heritage Management Plan. The RFP for the services of competent professionals to identify, assess and propose management measures for cultural heritage, assess and propose management measures for cultural heritage in the project area through the development and implementation of a cultural heritage plan was issued in October 2016.


Public Health Baseline Study

Health is integral to development and LHDA is committed to ensuring that the health of the people impacted by the Lesotho Highlands Water Project not only remains good but where possible it is enhanced by the Project. To ensure this, a Public Health Baseline Study was commissioned to collect baseline health data for future monitoring purposes

Field Liaison Manager, Maile Maile, Public Health Specialist, Dr Surinder Kaul and the consultants charged with the responsibility of undertaking the public health baseline studies.
This study aimed to determine the baseline status of social determinants of health and the burden of disease amongst communities in the project area.
    The study was made up of the following tasks:
    • Establishing a baseline statement of aggregate public health data which includes the social determinants of health, disease burdens and the health system;
    • Interfacing with the country’s main social and health management information systems to ensure co-ordination and effective use of existing routine data and the integration of additional data collected;
    • Creating a template for subsequent public health studies that may be required in resettlement host communities;
    • Establishing key indicators and procedures to complement the prior socio-economic baseline survey in monitoring of areas affected by Phase II of the LHWP

    The baseline data will also provide the required information for the Health Impact Assessment and the subsequent development and implementation of the Public Health Action Plan in close collaboration with the Ministry of Health (MoH).

    Health Impact Assessment and Public Health Action Plan

    The LHDA will commission a consultant to carry out a Health Impact Assessment (HIA) which evaluates the potential impact of the project on the local community's health. Following the completion of the HIA and its approval by the LHDA and MoH, and before the start of the major construction works, the consultant will also develop the Public Health Action Plan (PHAP) for the impacted populations, in close collaboration with the MoH and the Local Health Authorities.

    The consultant will then implement the PHAP in partnership with the MoH for the duration of the project. Close cooperation with the MoH will ensure that the health programme is sustainable after the end of the Project.


    A Request for Proposals has been issued for the following:

    Contract 6018: Professional Services for Health Impact Assessment, Public Health Action Plan and Implementation. LHDA requires the services of a consultancy to conduct a Health Impact Assessment (HIA), to prepare a Public Health Action Plan (PHAP), and implement the PHAP in the defined areas impacted by the Project. The PHAP shall be prepared in collaboration with the Ministry of Health (MOH), so that the Ministry continues the ownership of health service delivery and that there is seamless continuation of the health services in the Project area after completion of the construction activities.

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