The Stânca-Costești Hydropower Plant is a hydropower station on the Prut River, built near the localities of Stânca (Ștefănești), Botoșani, Romania, and Costești in the Republic of Moldova.
The geology of the area where the reservoir is located is quite uniform, consisting of deposits of clayey dust with sands and gravels, under which clays and Sarmatian limestones are found. The reef ridge at the site of the main structures is made up of relatively hard coquina limestones.
The surface area of the Prut River basin at the Stânca-Costești section is approximately 12,000 km², and the average multiannual flow is 81 m³/s. The maximum flow values are 4,700 m³/s at a 0.1% guarantee and 2,940 m³/s at a 1% guarantee. The minimum observed flow is 2.5 m³/s.
Purpose
The hydrotechnical node has as its main uses flood control of a capricious river, irrigation, water supply, hydropower, and aquaculture.
- The reservoir with a total volume of 1,400 million m³ has a flood control volume of 550 million m³, which allows for the attenuation of the flood with a 1% guarantee from 2,940 m³/s to 700 m³/s, and together with the downstream embankments, it protects 100,000 hectares of floodplain land from flooding.
- Irrigation can be developed over an area of 140,000 hectares, with 70,000 hectares on each side.
- Water supply is ensured through flows of 10 – 16 m³/s for downstream users.
- Energy is harnessed through 2 plants with one unit of 15 MW each, at a flow of 2 x 65 m³/s, with an average annual energy output of 2 x 65 GWh. The operation schedule of the hydropower plants is subordinated to the other uses.