Kv Mozambique - Malawi Power Line
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El 565 §M~w MOOVol. 4 P o WMstE - Electricidade de Mocambique Public Disclosure Authorized 9 400 kV Mozambique - Malawi Power Line Lw Public Disclosure Authorized Public Disclosure Authorized Environmental Impact Assessment Report Public Disclosure Authorized May, 2004 I Environmental Impact Study of the 400kV Mozambique - Malawi Power Line INTRODUCTION This report constitutes the Environmental Impact Study of the 400kV Mozambique- Malawi Power Line Project, prepared by IMPACT for the proponent - Electricidade de Mo,ambique. It should be noted that the study was only carried out on the Mozambican part of the line, corresponding to about 60% of total length. In order to benefit from the Southern Africa Power Pool (SAPP), set up in the scope of SADC to coordinate the interconnection of the power grids of the various countries, the Government of the Republic of Mozambique and the Government of the Republic of Malawi, decided to interconnect their power grids for the mutual benefit of the two countries. Thus, in order to respond to future needs, EDM and ESCOM intend to design and construct a 330 or 400kV transmission line, initially operating at 220 kV. The power to be used is generated at Hidroelectrica de Cahora Bassa and transformed at the Songo Substation, which interconnects to the Matambo Substation through two power lines. The Environmental Impact Study (EIS) described in this report refers to the power line that will be constructed between Matambo and Z6bue. The EIS has been prepared according to the requirements of the environmental legislation in force in Mozambique (Law 20/97 of 1 October) and the regulations promulgated under this law (Decree 76/98 of 29 December). The main objective of the EIS is the identification of the potential negative and positive environmental (physical, biotic and socio-economic) impacts derived from the implantation of the project, in its construction and operational phases. Recommendations and proposals for negative impact mitigation measures will be drawn up. The methodology adopted for this study is according to the conventional standards for carrying out environmental impact studies for transmission lines and the Terms of Reference prepared to this end. It comprises the following: * Description of the route according to an appropriate set of criteria, e.g., type of vegetation, physiographic characteristics, land use, etc. * Identification of decisive and specific impacts of the power line. * Impact classification, using the typical criteria for the assessment of impacts (extension, duration, intensity, likelihood, mitigation potential and significancy). Drawing up of mitigation measures for the construction and operational phases of the project. Impacto, Lda - Projectos e Estudos Ambientais 1 Environmental Impact Study of the 400kV Mozambique - Malawi Power Line PROJECT DESCRIPTION The proposed transmission line will have a length of about 210 km, of which about 60% in Mozambican territory (126 km). The pylons projected for this line will be of the Cross-Rope Suspension type, in combination with the Self Supporting type. The typical spacing between the pylons is 465m. For 400kV transmission lines the standard width of the corridor is 55m. The corridor should ensure a safe construction, operation and maintenance of the line. The use of rubber isolators, common in new transmission lines, is recommended. The report prepared by Trans-Africa Projects presents a specific and more detailed technical description. The line will be fed from the Matambo Substation, which, in addition to feeding the future 400kV line to Malawi, already feeds the lines to Chibata (Centre), Caia (Centre-North-East) and Tete Town Substations with 220kV and 33kV respectively. However, a new yard adjacent to the previous one will be installed, specifically to feed the new line to Malawi. The proposed transmission line will have a capacity of 200MW, superior to those of the lines that currently leave the Matambo Substation, which have a total capacity of 82.9MW. Initially, the line will operate at 220kV. A future increase to 400kV is foreseen. The line will have no ramifications. Impacto, Lda - Projectos e Estudos Ambientais 2 Environmental Impact Study of the 400kV Mozambique - Malawi Power Line POTENTIAL IMPACTS AND RESPECTIVE MITIGATION MEASURES ASSOCIATED WITH THE POWER LINE Construction Phase Table 1. Summary of the biophysical impacts and mitigation measures during the construction phase Impact Likelihood Extension Duration Intensity Significance Mitigation measures Soil erosion High Limited Long-term Medium Medium to low 1. To implement temporary erosion control measures during construction to minimize the loss of soil during the removal of vegetation in the corridor (e.g. sediment retention mechanisms to control floodwater such as protection nets, wooden stakes, etc). 2. To restore the natural contour lines of the corridor to avoid the accumulation of water and the potential for accelerated erosion. 3. To remove and heap up the topsoil (75 mm) separate from the rest of the residues (e.g. subsoil, rocks, etc). Restore the topsoil as a final layer in the whole corridor. To re-establish the indigenous herbaceous vegetation immediately after construction. Soil High Limited Short-term Medium Medium to low 1. To break up the soil to a depth of 60 to 100 centimetres, compaction with the use of a tool, mainly in the areas of agricultural use. Destruction of High Limited Long-term Medium Medium to low 1. To make adjustments to the transmission line corridor vegetation route so as to minimize the risk for threatened plant within the species communities or other communities of ecological corridor or cultural importance. 2. Manual removal of the vegetation in areas adjacent to river margins and of steep slopes. 3. To carry out selective felling or pruning of the trees Impacto, Lda - Projectos e Estudos Ambientais 3 Environmental Impact Study of the 400kV Mozambique - Malawi Power Line adjacent to the corridor, to avoid danger to people and goods. 4. To limit Contractor's access outside of the construction corridor and especially where the existence of threatened plant species/communities is known or suspected. To reduce the construction works area to a minimum in these areas. To prohibit access of vehicles or personnel outside the construction right-of-way without prior Contractor's approval. 5. To prohibit all the workers involved in the project from buying charcoal or firewood that may be offered for sale along the corridor, to avoid promoting the use of the corridor for commercial purposes. 6. To prepare and implement a training programme for educating machinery operators with respect to environmental sensitivity along the route. should observe a minimum Impacts on the Certain Limited Long-term High High 1. Clearing operations from the maximum water level reduction of distance of 15 metres aquatic environments. sensitive marks in rivers or other the Zambezi River margin habitats 2. The wetlands existing on should be avoided; when this is not possible, special care should be taken, such as: to limit construction to the dry season; to carefully clean equipment after work in areas infested with exotic invasive species; to prohibit the spilling of fuel and lubricants or disposal and abandonment of any other products. with an herbaceous cover, as soon Impact of High Limited Long-term Medium Medium 1. To replant the soil The re-establishment of invading as possible after construction. is the best way to avoid species a graminaceous layer infestation by invading species. Curative action, after invasion having taken place, is expensive and time- consuming. 4 Impacto, Lda - Projectos e Estudos Ambientais Environmental Impact Study of the 400kV Mozambique - Malawi Power Line 2. To eradicate invading species along the corridor in the first year after construction. To determine the need for actions after this maintenance period. The eradication should be carried out before the germination of the seeds in summer. 3. The clearing machines should be cleaned periodically, so as to remove any seeds that may have got stuck to the blades or the caterpillars. This care should be greater when areas are traversed where invading species occur. In these areas the possibility should be studied to use herbicides during machinery cleanup. Impact on the Likely Limited Short-term High (in Medium 1. To prohibit access of vehicles or personnel outside the fauna (reptiles the case of work servitudes, without prior approval of the power and deaths in transport company. amphibians) endangere 2. In case the existence of threatened reptile and d species) amphibian species is identified, it is recommended to accelerate construction work in these sections of the corridor. Impact on the Likely Limited Short-term High (in Medium to low 1. Some nesting places can easily be detected (e.g. nests avifauna the case of of large birds of prey, etc), and may be avoided, if deaths) possible, (divert the route from the tree) or collected in coordination with the environmental site officer and the Veterinary Faculty of the Eduardo Mondlane University or the Museum of Natural History. 2. To construct the line between April and September, i.e., outside the breeding season of the majority of species. Impacto, Lda - Projectos e Estudos Ambientais 5 Environmental Impact Study of the 400kV Mozambique - Malawi Power Line trees and other Removal of Likely Limited Permanent Medium to Medium to low 1. To mark the large indigenous and close to the riverine low endangered species trees within that should not be damaged vegetation and construction right-of-way loss of large during the works. access of workers outside riverine trees 2. To limit as much as possible the power line corridor. 3. To re-establish stabilizing vegetation on the margins and access roads immediately after the construction of the transmission line at river and stream crossings, as stipulated by the EIS and special contractual provisions. by the excavation Disturbance of Likely Surroundin Long-term Medium to Medium to low 1.