REVIEW OF THE LEGAL BASIS FOR DRAINAGE AND REGULATION OF THE SAVA RIVER (DEFENSIVE DIKES IN THE MIDDLE POSAVLJE AS A PRECONDITION FOR A SAFE EXPANSION OF THE CITY OF ZAGREB)

Drainage of excess water has nearly always been an important precondition, particularly given the way land is used in Croatia. Hydrological and climate conditions in our area are such that land drainage was and still remains one of the most important activities of water management. This, in particular, poses a frequent doubt when determining the order of investment priorities in case of insufficient funds for simultaneous solution of both drainage and irrigation. Since the middle of the 19 century, the problem of excess waters in the Upper Sava area became a key problem, especially in Zagreb and its vicinity due to accelerated economic development (traffic, crafts, trade, industry) and demographic trends, thus the government was solving the problem of drainage through long-term loans and legislation, i.e. water laws, while supporting certain regulation works which were gradually solving this problem in the endangered area. During the 19th century and later on, drainage remains a water management activity vital for creating favourable living and economic conditions. The construction of dikes in Zagreb since 1894 onwards created the conditions for further development of systematic drainage in the city. At the same time, defensive dikes protected the city from high water levels of the Sava and thus became a precondition for Zagreb's safe expansion into the lowland areas.