The size of the reserve then was 148.61km2. The reserve became a protected area because the high-quality freshwater supplies the Azat River which flows down to Yerevan and the surrendering forests. In 1990 the reserve became 291.96km2 which some adjacent lands were incorporated in it and in 2006–2007, the reserve was reduced to 238.78km2. The reserve has been official status to the IUCN Ia category. Since 1995, the reserve has been subordinated to the Ministry of Nature of Protection of Armenia, managed through its Agency for Biological Resources Management and operating as the Khosrov Reserve non-profit organisation. Between 2006 and 2007, a process was underway to develop and approve a management plan for the reserve which aims to improve the reserve's environmental and socio-economic status which came from a 1993 compliance from the Convention on Biological Diversity. In the first quarter of 2008, rural schoolchildren in the largest villages adjoining the reserve were involved in an awareness-raising program about the reserve. Among the programs was the campaign on leopard conservation as the reserve is one of the 'hotspots' for the Persian leopard. On 9 September 2008 the Visitor Centre in the Garni district of the reserve was opened for the visiting public and tourists to educate visitors and bring awareness about the reserve on its natural and human history. On 4 April 2012 the reserve was awarded with a European environmental and conservation diploma from the Council of Europe. The reserve's geology is rugged and has a typical mountain range, encompassing a dense network of main and branch ridges, high plateaus and deep canyons towered by volcanic shield massifs and peaks. There are traces of past tectonic activity of various faults and fractures. The rocks, volcanic deposits and igneous intrusions dates back to the Cretaceous and pre-Oligocene periods. The dominating rocks are Quaternary fragmental debris and effusive. Due to the hot weather and impact of water there is an intense aeoline process that has shaped the numerous natural geological figures and most slopes are steep, with declivity exceeding 30°. Middle elevations of the belt are 1500–2300 m above sea level covers about half of the reserve's territory representing highly rough terrain composed of fold and detrital ridges. A low elevation of the belt below 1500 m is marked by vast areas of badlands. The main rivers in the reserve are Azat and the Vedi]. It flows for 55 kilometers and has a basin that occupies 572 square kilometers.