Balaton can recover: water quality improvement project to be completed this year

A major development to improve the water quality of Lake Balaton was launched in spring 2021. The project will include various interventions in 11 watercourses of Lake Balaton and the reactivation of reed filter fields, which will restore the water quality protection function. The aim of the investment is to address the long-term water quality problems affecting the lake while protecting the economic potential of Lake Balaton.

The investment is being implemented by a consortium of the National Water Authority and the Central Transdanubian Water Authority with a budget of HUF 5.139 billion, provided by the European Union and the Hungarian Government as non-repayable grants. The project is being carried out by SZABADICS Construction Industry Zrt.

The development includes three project components:

• The development of the Lesence system will affect the settlements of Szigliget, Raposka, Hegymagas, Balatonederics and Nemesvita in the western part of the Balaton Highlands (LOT1)
• Reconstruction of the structures of the Kis-Balaton Water Protection System (LOT2)
• Reconstruction of small watercourse structures (LOT3)

Our newspaper wrote in detail in March 2023 about the work on the LOT2 and LOT3 project sections, which included the reconstruction of the Kis-Balaton Water Protection System structures: the 21T and 4T sluices underwent a complete architectural, mechanical and electrical renovation. In addition, the reinforced concrete track slab was cleaned and repaired, the pavement was repaired, and the bridge beams and steel railings were renovated. The control building was partially rebuilt, and the debris removal structure was also reconstructed.

In this article, we report on the implementation of the LOT1 part of the project, which László Fischer, the project leader of SZABADICS Építőipari Zrt., informed us about.

The site was taken over by the company in March 2021, after which development work could begin. Work has already been completed on several sites. These are:

• KÖV canal: bank stabilisation, sedimentation, culverts, substructure works for monitoring stations.
• Lesence stream: sedimentation, culvert, bottom weir, new channel linking the Világos stream and substructure works for monitoring stations.
• Tapolca creek: renovation of the oil catchment structure, installation of a floating grating.
• Two Gorges Creek: renovation of the oil interceptor, substructure works at the monitoring station.
• Nemesvitai ditch: construction of a sinking area, substructure works for monitoring stations.

The construction of the monitoring stations of the KÖV canal, the Lesence stream and the Nemesvitai ditch is ongoing. At the Lesence filter field site, linear and surface dredging is ongoing, as well as the construction of the bottom outlet structure and the rehabilitation of the outlet outfall structures.

Work on the Lesence filter field presented special challenges

Of the individual sub-elements, project manager László Fischer highlighted the surface and linear dredging tasks of the Lesence filter field. "We have to extract about 89 000 m3 of organic material from the area. The excavated material will remain in the filter field area and six so-called breeding islands will be created to facilitate nesting for birds."

"Working on the Lesence filter field presented us with a very difficult task, as the material in the area is almost entirely peat, with the exception of a few clay layers. We can only work in this "medium" with special, wide tracked machines", said László Fischer, explaining the challenges.

The contractor's team also had to deal with the environmental permit, which contains strict requirements on the time intervals during which work can be carried out.

Clean-up of inlet watercourses already completed

In parallel with the implementation of the LOT1 part of the project, the reconstruction of the small watercourse structures (LOT3) progressed. This included, among others

• the stabilisation of the Eger water body, the construction of a monitoring station
• the dredging of the Lovasi Gorge, the reconstruction of the embankment crest, the renovation of the draining structures and the construction of a sediment trap
• the reconstruction of the Cinege stream, the Kéki stream and the Örvényesi sedge and the construction of new sediment traps,
• and the construction of a new sediment trap for the Burnó stream.

The entire project is expected to be completed by mid-November 2023.