The Çubuk-1 Dam is a concrete gravity dam on the Çubuk Stream near Çubuk in Ankara Province, Turkey. It is located 12 km north of the center of Ankara and was built to control floods and provide drinking water to the city. Its construction lasted from 1930 to 1936; Mustafa Kemal Atatürk attended its inauguration on November 3, 1936. It was the first concrete dam constructed in Turkey and the first constructed in Ankara, and is recognized by Turkey's Chamber of Civil Engineers as one of the country's top 50 engineering feats. It is owned and maintained by the Turkish State Hydraulic Works and was constructed at a cost of 2.32 million TRY. The dam is 25 m tall, 900 m long and made of 120000 m3 of concrete. The aggregate for the concrete was derived from volcanic rock in nearby areas. It has a circular axis of 200 m and its arch-like design was used for stability. Hardly used, its reservoir has a normal volume of 1200 m3 and surface area of 1 km2. The dam's reservoir used to be a popular recreational area. Silt accumulation in the reservoir along with raw sewage being dumped upstream halted water supply from the dam in 1994. Since then, efforts have been ongoing to remove the polluted silt from the former reservoir bed. The area behind the dam will also be restored into a park once complete. Before being mostly emptied, the reservoir's elevations above sea level were 906.25 m at full capacity, 900 m at two-thirds capacity and 895 m at half.