The smaller part of the lake on the borders of Isparta is called Hoyran, and the southern part is called Eğirdir. A lake of tectonic origin has deepened only due to its lithological structure, which has also been affected by karstization. Lake Eğirdir is 917 meters above sea level and 482 square kilometers. The deepest part of Lake Eğirdir, which has a coastal length of 150 kilometers, is about 15 meters.
Eğirdir, where there is no great pollution so far, also feeds Kovada Lake. Although there are many settlements around the lake, it remains partially clean. For this reason, some of isparta’s drinking water is covered here. When viewed from above, the lake is the color of cyan, depending on the condition of the light because of the reflection at certain times of the day receives different colors. That’s why it’s called the Seven-Color Lake. Lake Eğirdir, where two land parts called Can Ada and Green Island are located, is fed by Gelendost River, Mill Tea, Akçay, Kocadere, Pupa River and many underground water springs.
Around 120 bird species live in Lake Eğirdir. An average of 200,000 waterfowl are recorded each year in the lake, which is an important wintering area for waterfowl. Applehead patka, crested patka, Hungarian duck and clumsy are among the waterbirds that live in the lake. Lake Eğirdir is a significant fishing, crayfish is another source of income. In addition, the lake is used in irrigation and energy fields. A 25-kilometer canal from Lake Eğirdir also provides water to the very small Lake Kovada. There were once more than 10 species of fish in the lake, but they decreased after the inoculation of foreign fish species. Due to the steepness and depth of its shores, the areas where birds will incubate in Eğirdir are limited. The Hoyran section is shallower and has reedbeds where birds can incubate.