Picture Långsjön-Tutviken shimmering under the Stockholm sun. This long lake isn’t just a pretty face. It’s a vital part of the Tyresån Lake System. Långsjön sits between Skälsätra and Tutviken two residential areas separated by its waters. It flows from west to east fed by Lake Drevviken and emptying into Tyresö-Flaten.
Långsjön has a rich history. Once its waters were too polluted for swimming. High bacteria levels made it unsafe. But things have changed. Improved water quality now allows for swimming. Warmer winters reduced surface runoff. This solved the bacterial problem. Levels of phosphorus and nitrogen however remain high.
The lake itself is shallow. Its shores are stepped. The surrounding area is flat rock terrain. Surprisingly few species live in Långsjön. The aquatic vegetation is limited mostly to reeds. This might seem disappointing but makes it a unique ecosystem.
Interestingly Långsjön’s older name was Tutviken. That name survives in a growing community along the lake’s southern shore. The island Solön sits almost in the middle of Långsjön. World War I and World War II left their mark. Remnants of fortifications are scattered around Långsjön’s shores. Especially on the northern side near Skälsätra. A former dance hall and festival grounds are now surrounded by houses.
Långsjön’s western inflow comes from Drevviken via Gudöån. The eastern outflow is via Gammelströmmen to Tyresö-Flaten. From there the water flows past Tyresö’s old mill and industrial remnants. It continues to Albysjön. From Albysjön the water splits into two flows. One goes through the steep Uddbyfallet. The other goes through Fatburen and Follbrinkströmmen. Finally it flows into Kalvfjärden an inner bay of the Baltic Sea. Tyresö Castle sits on a hill overlooking the bay. It’s a fascinating journey through history and nature all connected to the humble waters of Långsjön-Tutviken.