Page - 1439 - in Book of Full Papers - Symposium Hydro Engineering

ensure the required activities for the maintenance needed. All above considerations are related to the technical maintenance of the dams and their facilities as well as to the dam safety, respectively. The other side of the problem is presented by the water resources management of these small dam reservoirs. As already mentioned, after both the collapse of the Bulgarian agriculture and the population migration following the political change in 1989, many of these reservoirs are simply not needed. Hence, the interest for their ownership, operation and maintenance is directly not present. This is a severe problem since on the one hand, these small dams are extremely valuable facilities of the water infrastructure in the conditions of relatively scarce water resources in Bulgaria. Furthermore, although small but numerous, they contribute to the damping of the peaks of flood events in whole catchment areas as this was the case of the flood in August 2014 in Northwestern Bulgaria [5]. On the other hand however, the long-term absence of proper technical maintenance substantially reduces their safety with all dangerous consequences. 2.2. LEGISLATIVE ENVIRONMENT, CODES AND REGULATIONS Currently, there are almost 40 acts and subordinated legislative documents covering the whole spectrum of hierarchical range which regulate all aspects of the technical operation of the dams, latters’ safety and the technical maintenance of the facilities [6]. Discussing them here would go far beyond the frame of the present report. A special feature in this connection is the fact that the property and the operation of the water reservoir is still strictly separated from the operation of the dam and its facilities. In some cases, this causes severe problems in the operation as a whole set of interrelated activities, and attempts at highest administrative level are made currently to overcome this formal separation. It should also be noted that this regulatory system is a dynamic structure being continuously in development and improvement in terms of more adequate reflection of the reality for decrease of the identified problems – technical, administrative, legislative, operational, environmental etc. In all cases when a particular problem is not covered by the current national regulations, the most advanced solutions to this problem available worldwide are applied. To serve this purpose, ICOLD Bulletins (for example Nr. 115, 116, 131, 138, 148), EU Directives and related documents, internationally recognized recommendations and guidelines as well as modern best practices are implemented. Other related sources are considered, too – for example [7, 8]. Last but not least, special attention is also paid to the recent research activities in this field, especially to the ones within the European Union. Here, [9, 10, 11] can be mentioned as examples. The environmental aspects of the small dams are subject to special concern, too. Recently, the legislative component of these aspects is rapidly growing, especially with the implementation of the strategies, policies and directives of the European Union. One important issue related to the operation of 1439