Büyükçekmece Gölü

Lake Büyükçekmece is a wide body of water on the Marmara coast west of Istanbul, and it supplies part of the city's drinking water. Geographers describe it as a liman or lagoon lake, because it began as a bay where a river valley met the sea. The lower valley of the Karasu stream, which runs south from the Çatalca area, was drowned by the rising sea and first became a bay. Over time a bar of gravel, sand and clay built up across the mouth of the bay, cutting it off from the sea and creating the lake we see today. The narrow channel linking the lake to the sea was for centuries an obstacle that travellers had to cross. The lake takes its name from that crossing, because before there was a bridge people were hauled across on large rafts pulled by rope, and these rafts were called çekmece. According to the district history of the Büyükçekmece District Governorship, Byzantine sources name the settlement on this shore Atirus or Atira. A many-arched stone bridge was later built over the channel, and this structure, known as the Kanuni Sultan Süleyman Bridge, still stands at the seaward end of the lake. According to figures on English Wikipedia, the lake covers about 28 square kilometres, is roughly 7 kilometres long and about 2 kilometres wide. Deepened by works of the State Hydraulic Works, the lake is a little more than 8 metres deep at its deepest point. The lake's link with the sea was closed by a dam at the end of the 1980s, turning it into a freshwater reservoir. According to the water resources page of İSKİ, the Büyükçekmece Dam entered service in 1989, and the lake's water is treated at the Büyükçekmece Drinking Water Treatment Plant before being sent to the city. The same source notes that the dam can supply about 100 million cubic metres of water a year and that its catchment reaches 620 square kilometres. Between the dam and the sea a small brackish lake, water pockets and reed beds remain. The lake also matters for birds, and BirdLife International listed it as an Important Bird Area in 1989. Sources record that the lake once held about 30 fish species, that the number has fallen to 15, and that some of these were introduced later. On the northern shore, on a peninsula, lies the Hezarfen airfield. Part of the shoreline is being laid out as the Lake Büyükçekmece Natural Habitat Park under the Istanbul Metropolitan Municipality's programme of green belts around drinking water catchments. According to Turkish Wikipedia, the project has 12 stages and the first two were opened to the public on 14 March 2024. The project includes walking and cycling paths, rest areas and birdwatching points. Walking along the shore path of this park, you see the reedy islets in the middle of the lake and the settlements on the far shore in the same frame. One of the best ways to take in the lake is to look north towards the dam embankment from around the historic bridge at the seaward end. While walking along the shore it is worth remembering that this is a drinking water reservoir. Under catchment protection rules, swimming, entering the water and littering the shore are not appropriate. For birdwatching, calm mornings and the migration seasons of spring and autumn are the most rewarding. Binoculars and a quiet walk make it easier to spot the waterbirds among the reeds. Shade is limited on the shore, so bring a hat and water on summer days. The southern end of the lake is within walking distance of the Büyükçekmece district centre, and Kurşunlu Han and the Kanuni Bridge can be seen on the same outing. Those coming by public transport can take İETT buses from the westernmost metrobus stops to the centre of Büyükçekmece. We recommend checking current route and timetable information through İETT's official channels. According to the governorship's district history, Büyükçekmece has always been a stopping place for armies and travellers, which is why remains of a caravanserai, inns and a bathhouse are found in the district. For a long time Büyükçekmece was a sub-district of Çatalca, and it became a district under a law passed in 1987. According to Turkish Wikipedia, all the stages of the natural habitat park project together cover an area of more than 12 million square metres. İSKİ explains that Istanbul is supplied by surface water sources and that water arriving in the rainy seasons is collected in reservoirs; Büyükçekmece is one of the western links in this chain. At sunset the surface of the lake turns orange, offering a calm view for anyone watching from the shore.