Kortówka is a small stream with a depth reaching 1.5 m. It has its source in the biggest lake in Olsztyn – Ukiel – and heads south. Then, it passes through Lake Kortowskie to finally flow into the Łyna from the left side.

The stream is a part of the landscape of the Kortowo campus, which is located in the south western part of Olsztyn. Kortówka has become a significant element of the so-called kortowski experiment that was started in 1956 – to manage the water treatment of Lake Kortowskie.