The first mention of a Danube stage at Jochenstein is to be found in the 1918 drafts from the Bavarian canal construction authorities for the major Rhein-Main-Donau shipway. However, the Kachlet plant at Passau, constructed by Rhein-Main-Donau-AG (RMD) between 1922-27, took priority for shipping since it was possible to ease the dangerous shallows in this section by means of the backwater. A further delay for the Jochenstein project was tied in with the construction of Ybbs-Persenbeug power plant, which was constructed from 1938 by RMD and, at the time, was considered to be more important for the development of the Danube.
In 1943, Alpen-Elektrowerke AG published a new general plan for the development of the Danube, which only envisaged a single stage in Aschach in the Passau-Ybbs section, with a gross head of 27.5 m. The realisation would certainly have been politically possible, but it was unrealistic on account of a lack of building material in the final years of the war.
It was only with the enormous energy poverty in the Southern German region, after having been cut-off from the Central German electricity suppliers, that new impetus was brought to the Jochenstein power plant project. In 1948, RMD designed the initial preliminary draft for the structure that was later to be realised. One year later saw the founding of a planning consortium through Österreichische Elektrizitätswirtschafts-AG (Verbundgesellschaft) and the German RMD. This consortium took control of the planning and handed the finished appraisal draft over to Donaukraftwerk Jochenstein AG, which had been recently founded on 15 February 1952.
The start of preliminary works in September 1952 also revealed problems that didn’t exist at other Danube power plants: on account of its position directly on the Austrian-German border, it was necessary to protect the entire construction site grounds as an enclave in such a way that the sovereignty of both countries could be assured. The situation was somewhat eased by the fact that Jochenstein lay to the west of the Russian-American zonal border and therewith found itself on the southern bank of the Austrian-American zone and the northern bank of the Bavarian-American zone.
By April 1953, the cofferdams on both sides of the banks had been constructed and the subsequently sectioned off construction pits were pumped out. The construction site facilities were completed and excavation works began for the foundations. In October 1953, the two right bank weir fields had been completed to such an extent that it was possible to flood the excavation pits in this area. The southern sluice, which had to be available to shipping during the further construction work, was able to assume its role in April 1954.
The catastrophic floods of July 1954 represented a setback for the construction plans. Although it had been possible to bury the moving parts as a precautionary measure, the construction site in the middle of the Danube was still completely flooded. At the time, the through flow of 9,600 m³/sec. lay significantly above the hundred-year flood of February 1862, with its 8,400 m³/sec. Nevertheless, it was possible to start the main assembly of turbine 1 just one month later.
The turbine house was constructed from north to south, machine block by machine block. January 1955 saw the encasing of the first three hydroelectric generating sets; following the pumping out of the next construction pit, it was possible to start construction work on the remaining buildings – along with the two adjoining weir fields. After the construction pits had been flooded in March, and the unproblematic partial filling on 12 April 1955, the three most northerly hydroelectric generating sets were able to start regular operations in May.
Autumn 1955 saw the completion works on the southern power house and the adjoining weir fields, followed by the first complete reservoir filling in the December. Completion of the construction works and the ultimate commissioning of the Danube power plant of Jochenstein was able to go ahead in August 1956.
Parallel to the power plant construction, comprehensive dam construction measures were necessary in the reservoir area, which extended right back to the tailrace of Kachlet power plant at Passau. It was necessary to reposition part of Nibelungen federal highway; replacement building were erected for flooded farms. Two plant residential complexes with semi-detached houses were erected on both banks of the river in order to provide accommodation for the power plant employees.
Originally designed to be open-air, a roof was put on the assembly yard next to the lockage in 1993, enabling work to go ahead irrespective of the weather. Shortly afterwards, the control room was redesigned and the plant’s windows replaced. July 2000 saw the opening of the "Haus am Strom" information centre, next to the power plant. This joint Austrian-Bavarian project comprises two new buildings - a "fish" and a "river pebble" - and also integrates the former customs building. Inside there is an exhibition room, a lecture hall and a restaurant.