Flowing towards the Black Sea. That’s the Riva Deresi for you. This waterway is also known as Riva Çayı or Çayağzı Deresi. It winds its way through the northern part of the Kocaeli Peninsula.
Let’s dive into the story of Riva Deresi. It begins its journey near Tepecik village. This village is part of Gebze in Kocaeli province. The river then meanders into Istanbul province. It passes through Pendik and Çekmeköy districts before reaching Beykoz. Here, it finally empties into the Black Sea. At its mouth, you’ll find Çayağzı. This is the old Riva neighborhood. It shares its name with the river.
The Riva Deresi boasts some impressive stats. Its water collection basin spans 853 square kilometers. It stretches for 32.2 kilometers. The river’s width can reach up to 25 meters. Its average depth is 51 centimeters. Annually, it carries 236×106 cubic meters of water. The average flow rate is 0.63 cubic meters per second.
Did you know the Riva Deresi helps supply Istanbul with drinking water? It feeds the Ömerli Dam Lake in Pendik. This lake provides 48% of Istanbul’s drinking water. Water is collected from a 38-kilometer stretch of the river. The total length of the river is 70 kilometers.
After the Ömerli Dam Lake, the Riva Deresi flows past several villages. These include Koçullu, Ömerli, and Sırapınar. It also passes Huseyinli, Bozhane, and Öğümce. Then it meanders through Göllü and Paşamandıra. Finally, it reaches Çayağzı where it meets the sea. Almost 80% of this section is surrounded by forest. The remaining land is used for farming. Some is also used for pasture.
Interestingly, the Riva Deresi is suitable for boating. Its calm waters and wide surface make it ideal. Local fishermen also engage in small-scale fishing. However, pollution has been a problem in recent years. Industrial facilities and wastewater have been discharged into the river. Fortunately, in 2020, the Mayor of Istanbul took steps to address this issue.
The area around the Riva Deresi is home to rare and endemic plant species. These are now under threat. The river’s ecosystem is quite fragile. It needs protection.
Once called Rhebas, now Riva Deresi is more than just a river. It is a lifeline for Istanbul. Its waters sustain both people and nature. The Riva Deresi shows us the importance of preserving our natural resources. Let’s hope efforts to clean up the river will succeed. Then the Riva Deresi will continue to flow for generations.