BALWOIS 2008 – Ohrid, Republic of Macedonia – 27, 31 May 2008 1/7 Disturbed River Corridors and Protection Measures Cvetanka Popovska 1) , Dragan Ivanoski 1) , Milorad Jovanovski 2) University of Ss. Cyril and Methodius, Faculty of Civil Engineering, 1) Department of Hydraulics, Hydrology and River Engineering 2) Department of Geotechnics, Partizanski odredi bb, PO Box 560, 1000 Skopje, Macedonia e-mail: popovska@gf,ukim.edu.mk Abstract Integrated water resources management addresses issues of human security and sustainable development. Human security and well-being are closely related to maintaining ecosystems and avoiding environmental degradation. The concept of sustainable development is embedded to human security, which encompasses the physical security of individuals and communities, but also economic security, flood security, health security, environmental security and political security. The relationship between human security and the environment is most pronounced in areas where human dependence on access to natural resources is greatest. This paper will present a case study of disturbed river corridor and proposed restoration measures for its protection. The case study is Lepenec River corridor in the area of the bridge on Skopje Bypass Motorway in the Republic of Macedonia. The Lepenec River as a central part of the neighboring settlements plays an important role. The bridge and the alignment of the highway are crossing the river valley almost perpendicular that impacts flood and environmental management. Flood analysis with bridge modeling has been carried out, and some protection measures have been proposed. The erosion processes will be discussed with special attention to riverbed and accompanying trees and bushes which are emphasizing the character of the river corridor itself. Key words: river corridor, flood, hydraulic analysis, erosion, protection measures Introduction The EIA Directive regulates the Environmental Impact Assessment of the effects of projects on the environment. It was introduced in 1985 and was amended in 1997 and the Member States have to adopt all measures necessary to ensure that projects likely to have significant effects on the environment by virtue, inter alia of their nature, size or location are made subject to a requirement for development consent and assessment in regard to their effects. The Environmental Impact Assessment should identify, describe and assess the direct and indirect effects of the project on the following factors: a) human beings, flora and fauna, b) soil, water, air, climate and the landscape, c) material assets and the cultural heritage, d) interaction between the factors. Within the project activities for Skopje Bypass Motorway an EIA study has been prepared (LAHMEYER International, 2002). The Lepenec River plain was identified as the most sensitive in this motorway section. In this study the following environmental aims were considered: protection against erosion due to the overgrazing as well as limitation of the afforestation; preservation and development of the riparian vegetation by setting up a buffer of at least 10 m to the river banks (above high water level); protection of the wetland relics and development of spawning habitats; protection and development of coppices and degraded oak-forests on the hills and in the valleys; preservation of the structural diversity of the agricultural area. These measures were proposed according to the evaluation of the state of the biotopes with regional and local importance, such as loss of pastures and shrubs, loss of vegetation and riparian cover, intensification of grazing and erosion, eutrophication and land exploitation (gravel pits, intensification of agricultural use). The sensitivity against loss of vegetation due to the road, bridge and construction works is also high. Special attention in the EIA study was given to potential impacts and conflicts in the study area. The crossing of rivers by the road will result in loss of the flora and fauna in the riverbed and the riparian vegetation underneath the road. The crossing could also cause the barrier effects for the aquatic fauna because of the reduced incidence of light underneath bridges. Concrete construction in the