Role of Kis-Balaton
“Role of Kis-Balaton”
Water quality of Balaton started to deteriorate due to civilization environmental impacts from the 1940’s then this process accelerated from the 1960’s. Deterioration of water quality occurred in the eutrophization of the lake and concentration of nutrients. Nutrients got into Balaton in high quantity with untreated sewage, by fertilizer leaching in huge area and in consequence of improper management of liquid dung of livestock plants. River Zala, emptying into the Keszthely-bay is the most significant among the surface watercourses, which provide influx of Lake Balaton. This river transports 40-45% of the total water discharge and its catchment area is 2600 km2. Balaton is the recipient of more than 45 smaller-larger discharge and varying water quality watercourses on the Northern and Southern shores. The most severe situation was in the Keszthely-bay where the seaweed was forced back and algae dominated due to plethora of nutrients.
In order to roll back these undesirable phenomena several complex plans were made from the mid 1970’s for the use of the lake for recreation. During several decades, among others, sewage disposal and treatment, modernization of livestock farms and implementation of the first phase of Kis-Balaton Water protection System (Lake Hídvég, Ingó-holt) took place in the catchment area of the lake in order to decrease diffuse load.
The simple aquatic organisms use dissolved nutrients arriving in the water of the first phase of Kis-Balaton Water Protection System to build their own bodies in a retention time of 45 days.
About 1,5 m average water depth was formed in the water of Lake Hídvég. This relatively shallow water warms up easily and it is hardly covered by higher rate plants. Reed and rush can be found along the shore and dams, moreover seaweed can be found in the water-body. Light reaches the water surface without hindrance so it is ideal to remove nutrients originating from the catchment area of Zala.
Flora of Lake Fenéki completly differs from the ones of Lake Hídvég. Algae do not over reproduce in this area due to higher rate plants. The higher rate plants build nutrients into their own bodies reducing the quantity of nutrients getting into Balaton in this way. Entire natural environment, as well as the flora and fauna of the area take part in removal of the nutrients as a filter-system.
Kis-Balaton Water Protection System Phase II. assures further increase of nutrient removal efficiency of the system and operation according to the nature conservation point of view. By implementation the project (expectable ending date: 31st March 2015) all the expectations formulated by representatives of the special fields mainly water and nature conservation experts will be met. The project focused on working up a flexible water navigation that means regulation of the route of water with the help of regulating structures and sluice-gates and on the base of the data of the monitoring system (biomonitoring, water quantity and quality). As a result of this Kis-Balaton Water protection System can operate with maximum efficiency the possible best quality water gets into Balaton in an adjustable way. In addition, assurance of ecological water demand of Kis-Balaton as significant water conservation living system can be solved on the base of the monitoring data. The implemented controllability makes it possible that the occurrent nature conservation and ecologically negative processes could be modified and reversible.
The developments assure flood protection and excess water protection goals as well. Better efficiency can be reached in the course of excess water protection by the renovated pump-stations. The large resorvoir area enables the drainage of floods on lower level.