After it passes the cemetery of the neighboring Mali Mokri Lug, it reaches the neighborhood of Medaković III where the stream is conducted underground for the first time.

The area in the lower valley of the now underground stream was used for digging earth and gravel which were used to cover and drain the swamps on the Sava's right bank, so that neighborhoods of Savamala and Bara Venecija could be constructed, and for the building of Belgrade's central railway station.

After the works were completed, the area around Mokroluški potok was left as a steep, elongated cut in the ground and so was given its present name (Prokop).

Both Mokri Lug and Kumodraž are located on the hills, so the natural inclination allowed for the water to flow downhill to Singidunum.

Czech émigré Heinrich Smutek, arranged a large estate (with a brickyard) and a garden in the area, and opened a kafana "Smutekovac".