Water supply represents a long lasting problem in the Mediterranean region, and particularly on the islands and in isolated areas. This conclusion was reached after several years experience in solving these problems, within the activities of the UNEP Centre for priority actions on the Mediterranean. The shortage of water imposses increasing demands upon the water management and on the policy makers, since this problem is not only technical but is becoming a socio economic problem of wide interest. The paper presents the activities of the UNEP-MAP Centre, the gained experience and the suggestions for solving problems related to water resources management as a part of an integrated environmental management system. The paper also presents the main characteristics of two pilot projects.