Kalochori lagoon is considered the northern gate of the National Park. It is located 8 km. away from the city of Thessaloniki. It is a special and interesting coastal wetland. Although it is on the edge of a large urban city and is under considerable pressure, it is one of the most important areas of the National Park, as it has numerous birds and other organisms throughout the year. Large numbers of flamingos can be found there often, since there is plenty of food in its shallow waters. The lagoon offers impressive images, with the birds feeding in the water and in the background the urban landscape and the cranes of the port of Thessaloniki.
Kalochori lagoon is unique in Greece, as it is a “new” wetland that was gradually created from the mid-60s, as a result of land subsidence caused by the over-pumping of water from underground aquifers combined with loose texture of the soil.
Before the diversion of the Axios river, in 1934, the area was covered by extensive marshes. In the period 1955 – 1980, the Water Supply Company of Thessaloniki created wells in the area of the Gallikos river to supply for the needs of the citizens of Thessaloniki, while in the same period more wells were created by private individuals. As a result, the area’s underground water level has dropped by 36 meters since 1976. Due to its loose structure, the clay soil subsided in various parts of the lagoon to a depth of up to 3-4 meters below sea level.
In the “basin” that was formed, the current lagoon was created from underground seawater, but also from the rainwater of the settlement of Kalochori. The creation of the lagoon also contributed to the construction of the coastal embankment, in 1976, to protect the settlement of Kalochori from possible floods.
Today, the Kalochori lagoon covers an area of 2,260 acres. The deapth of the lagoon is 0.5 – 1 meter below the sea. The phenomenon of sedimentation is also visible at the mouth of the Gallikos River, where the telephone poles, that used to be in pasture, are now in the lagoon.