Nerezi and Bardovci. According to the 2021 census, the City of Skopje itself comprised 422,540 inhabitants and 526,502 within administrative limits. The City of Skopje reaches the Kosovo border to the north-east. Clockwise, it is also bordered by the municipalities of Čučer-Sandevo, Lipkovo, Aračinovo, Ilinden, Studeničani, Sopište, Želino and Jegunovce. Hydrography The Vardar river, which flows through Skopje, is at approximately from its source near Gostivar. In Skopje, its average discharge is 51 m3/s, with a wide amplitude depending on seasons, between 99.6 m3/s in May and 18.7 m3/s in July. The water temperature is comprised between 4.6 °C in January and 18.1 °C in July. Several rivers meet the Vardar within the city boundaries. The largest is the Treska, which is long. It crosses the Matka Canyon before reaching the Vardar on the western extremity of the City of Skopje. The Lepenac, coming from Kosovo, flows into the Vardar on the northwestern end of the urban area. The Serava, also coming from the North, had flowed through the Old Bazaar until the 1960s, when it was diverted towards the West because its waters were very polluted. Originally, it met the Vardar close to the seat of the Macedonian Academy of Sciences and Arts. Nowadays, it flows into the Vardar near the ruins of Scupi. Finally, the Markova Reka, the source of which is on Mount Vodno, meets the Vardar at the eastern extremity of the city. These three rivers are less than long. The City of Skopje incorporates two artificial lakes, on the Treska. The lake Matka is the result of the construction of a dam in the Matka Canyon in the 1930s, and the Treska lake was dug for leisure purpose in 1978. Three small natural lakes can be found near Smiljkovci, on the northeastern edge of the urban area. The river Vardar historically caused many floods, such as in 1962, when its outflow reached 1110 m3/s−1. Several works have been carried since Byzantine times to limit the risks, and since the construction of the Kozjak dam on the Treska in 1994, the flood risk is close to zero. The subsoil contains a large water table which is alimented by the Vardar river and functions as an underground river. Under the table lies an aquifer contained in marl. The water table is 4 to 12 m under the ground and 4 to 144 m deep. Several wells collect