Lake Eğirdir: Türkiye’s Changing-Color Freshwater Wonder

Stretching across 482 square kilometers in Isparta’s Lakes Region, Lake Eğirdir (formerly Eğridir) is Türkiye’s second-largest freshwater lake and a remarkable ecological and geological feature. With its shape-shifting blue-green hues, dual islands, ancient shoreline settlements, and hydrological richness, this lake is more than a tranquil destination—it is a living system shaped by time, tectonics, and tradition.

The name “Eğirdir” was officially adopted in the 1980s to replace “Eğridir,” which means “crooked” in Turkish. The new name evokes elegance—suggesting spinning, flowers, and balance—though many locals still affectionately use the older form. The lake’s history is far older than its modern name. Ancient coins from the nearby city of Parlaos depict ships, hinting at centuries-old navigation on these waters. Civilizations from the Hittites and Romans to the Byzantines and Seljuks left traces in nearby settlements like Prostanna, Bedre (now Gökçe), and Akrotiri—modern Eğirdir.

A Lake with a Complex Soul: Hydrology and Geology

Lake Eğirdir is fed by over 40 springs and seasonal streams, including the Pupa, Hoyran, Yalvaç, and Çay. Its basin covers 3,309 km², and the lake itself is divided by the Hoyran Strait into two bodies: the main Eğirdir Lake and Hoyran Lake to the north. With an average depth of 7 meters and a maximum of 13 meters, it has a total volume of around 4 billion m³. The water retention time ranges from 2.5 to 3 years.

Geologically, the lake is part of the Eğirdir–Kovada Graben, a tectonic depression formed by fault movements. Two distinct sedimentary stages—the ancient Yeşilköy Formation and modern alluvial deposits—mark the terrain. The area is seismically active, as evidenced by a magnitude 5.1 earthquake along the Esinyurt Fault in 2007.

There is no thermal stratification in Lake Eğirdir, which means its waters are mixed year-round—a crucial factor affecting its aquatic ecology.

Biodiversity: A Struggle Between Native and Invasive Species

Lake Eğirdir’s ecosystem has been significantly altered by human activity. Once home to a rich array of endemic species like Capoeta pestai (Eğirdir barb) and Pseudophoxinus egridiri (Eğirdir minnow), the lake saw ecological collapse following the introduction of pike perch (Sander lucioperca) in 1955. Initially intended to boost commercial fishing, this predator devastated native populations and led to the extinction or critical endangerment of several species.

Later introductions, such as Prussian carp, big-scale sand smelt, and mosquitofish, further changed the lake’s food chain. Still, some species—like the killifish (Aphanius anatoliae anatoliae)—have rebounded due to reduced pike perch numbers.

Crayfish (Astacus leptodactylus) were once the lake’s economic cornerstone, but crayfish plague wiped out most of the population in 1986 and again in 2004. Though harvesting resumed in the late 1990s, numbers have never returned to former levels.

Economy and Water Use

Lake Eğirdir provides irrigation water for about 45,000 hectares of farmland and supplies drinking water to Isparta city. Water also exits through the Kovada Canal into Lake Kovada and is drawn out by 11 irrigation pumps.

Historically, fisheries were highly profitable—reaching over $3 million annually in the late 1970s. However, overfishing, invasive species, and pollution have diminished economic yields. Today, fishing persists but at much lower volumes. The lake remains vital for local livelihoods, especially in agriculture and eco-tourism.

What to Do at Lake Eğirdir

Recreation: Visitors can enjoy swimming, kayaking, paddleboarding, or taking boat tours from the shores near Eğirdir town. Angling is allowed in designated zones, and photographers are drawn by the lake’s unique hues and misty mornings.

Visit the Islands: The long causeway leads to Can Ada (Life Island) and Yeşil Ada (Green Island). These twin islands are charming escapes, with old stone houses, pensions, and waterfront cafes serving fresh lake trout.

Cycling & Hiking: The surrounding hills offer panoramic viewpoints and well-marked trails. Eğirdir also lies on the St. Paul Trail, a long-distance hiking route tracing the path of the Apostle Paul.

Birdwatching & Nature: Spring and autumn migrations bring a variety of bird species to the lake. Nature lovers can visit Kovada Lake National Park, 30 km away, for forest hikes and wildlife spotting.

How to Get There

• By Car: Eğirdir is accessible via the D685 highway, around 35 km from Isparta city and 107 km north of Antalya.

• By Bus: Regular buses run from Isparta, Afyon, and Antalya to Eğirdir town.

• By Air: The nearest airport is Isparta Süleyman Demirel Airport (ISE), about 50 km away.

Best Time to Visit

The best months are April to June and September to October, when the lake is at its most colorful, temperatures are mild, and water levels are stable. Summers are warm and suitable for swimming, while winters offer a more solitary, peaceful atmosphere.

Nearby Places to Explore

• Kovada Lake National Park – A peaceful natural reserve south of Eğirdir.

• Gölcük Crater Lake – A volcanic lake near Isparta city, perfect for picnics.

• Yalvaç – An ancient city with Roman ruins, just northeast of the lake.

• Davraz Ski Center – Winter sports area only an hour away.