Technikatörténeti szemle 4. (1967)
TANULMÁNYOK - Károlyi Zoltán A Sió csatorna múltja és kialakulása
and the decrease of the lake level by 3.8 metres were contemplated. In the course of this work watermills and their sluices disappeared (the last in 1852). In 1855 the state drained the estuary toy cutting, but there was no great improvement in the situation: the time to time overflowing water from the lake often inundated the Sió valley. The communication safety of the railway on the southern shore of the Lake Balaton, built in 1858 called for the immediate regulation of the level and water discharge. Consequently in 1863 the sluice at Siófok was built. The 18 m 3 /s water discharge capacity of the sluice with a wooden construction and the 8 m 3 /s water-sinking per section did not prove sufficient. The high level of the Lake Balaton in the years 1871—1883 endangered both the sluice and the Sió valley. In 1891 at last a new stank was built and as a third stage, between 1857 and 1902 the bed was formed with a 50 m 3 /s capacity up to Kapostorok and with a 90 m 3 /s capacity till the Danube. The maintenance of the sluice at Siófok caused great problems due to the hollowing out of the tailrace. Its renovation could not be postponed. As according to long-term plans the Sió would be made navigable in five steps, between 1941—1946 a look of 12 X 83.5 m basic area was built. The lock having been finished in 1946 the rebuilding of the sluice for level regulation could be started. Instead of the eight 1.70 m wide tables of the old structure it now has two 4 m wide tables and its foundation body is a single reinforced concrete lowering case, the cutting edge of which is 12.60 m deep under the zero level of the Lake Balaton. The new estuary works form a reliable assurance of the development of both the Sió valley and the Balaton region.
