What Wikipedia says

Lake Plastiras is an artificial lake fed by Tavropos river, located in Karditsa regional unit, near the city of Karditsa, Greece. The lake is named after the Greek general and politician Nikolaos Plastiras, who was the first to visualize the construction of an artificial lake in the area.

After WW2, the (then newly formed) Power Corporation adopted the project as part of their effort to electrify the country. An international contest was held in 1953 that was won by the French Omniun Lyonnais. The building of the dam started on December 14, 1955. On October 30, 1960 the dam was officially inaugurated, although the flooding may have started as early as the last months of 1959.

Today the lake holds up to 400 million cubic meters of fresh water. It is used for irrigation and as a power source of a hydroelectric plant, but also as the main water source to the city of Karditsa. Due to its altitude (one of the highest in Europe) the Tavropos Reservoir is a popular tourist resort in Greece, as the formed landscape is quite unique. Agrafa is a mountainous region in Evrytania and Karditsa regional units in mainland Greece, consisting mainly of small villages. It is the southernmost part of the Pindus range. There is also a municipality with the same name, the Municipality of Agrafa, but it covers only a small percentage of the area.

The fiercely independent spirit of its people, known as Agrafiotes, is matched by a harsh and forbidding landscape. The central Agrafiotis River valley is surrounded on three sides by a steep 2,000-metre wall of mountains, and on its south side the river drains via a series of narrow and often impassable gorges into the man-made Lake Kremasta. The other great river of Agrafa, Tavropos (aka Megdovas), feeds two man-made lakes: Plastiras (N) and Kremasta (S).