Thuong River in the sunset (photo: Thien Phong)

Bac Giang has three major rivers named Cau,Thuong and Luc Nam Rivers. These are three headstream rivers, focusing on pouring water into Pha Lai, where borders three provinces of Bac Giang, Bac Ninh and Hai Duong. Pha Lai River flows downstream in a section to Gia Binh of Bac Ninh receiving more water of the Duong River, dividing the water from the Red River to flow, then divided into two river branches to the sea. The river branch flows through Hai Duong to Thai Binh is the Thai Binh River. The river branch flows through Hai Duong to Hai Phong is the Kinh Thay River. All these rivers form a system, called the Thai Binh River system. The Thai Binh River system provides irrigation water and is a convenient transportation base for the Northern provinces of the Northern Delta.

In addition, the Thai Binh River system has a very important military position. In history, Northern feudal enemies often exploited to this river system to fight at Hanoi and Bac Giang (known as the Northern border area of the Thang Long Citadel). In 938, Nam Han troops intended to enter into the mouth of the Bach Dang River by the Ngao River (Quang Ninh) to the Kinh Thay River to Pha Lai, and were defeated by Ngo Quyen at the mouth of Bach Dang river. In the eleventh century, Ly Thuong Kiet set up a defense on the south bank of Nhu Nguyet River (Cau River) to resist Tong troops. During the Tran dynasty, the Nguyen-Mong troops brought foot-soldiers to Lang Son, crossed Xa Ly pass to Bac Giang coming to Ha Noi, and the navy followed the Luc Dau River to join foot-soldiers in Pha Lai. The Tran attacked the enemy in Xa Ly and Noi Bang passes, (belong to Luc Ngan, Bac Giang) and then retreated along the Luc Nam River to Pha Lai, and at the same time defeated the navy so they failed.

Three rivers of Bac Giang are ones with a length of over 100 km and have a basin area, average water volume compared to the system of large and small rivers in our country. 

 Cau River in the afternoon (photo: Thien Phong))

Cau River has a length of 290 km, the section flows through Bac Giang territory with a length of 101 km. Cau River has two large affluents located on the right bank including Cong River and Ca Lo River. The annual water flow of Cau River is about 4.2 billion m3. Currently, there is an agricultural hydraulic system on the Cau River serving irrigation water for the districts such as: Tan Yen, Viet Yen, Hiep Hoa, a part of Bac Giang city and Phu Binh district, Thai Nguyen province.

The Luc Nam River has a length of about 175 km, the section flows through Bac Giang province with a length of about 150 km,including main affluents such as Cam Dan, Thanh Luan, Ran and Bo Rivers. The annual water flow is about 1.86 billion m3. Currently, 170 works are mainly lakes and dams built on the Luc Nam River system to supply irrigation water for districts such as Son Dong, Luc Ngan and Luc Nam.

The Thuong River has a length of 87 km, including main affluents such as Hoa, Soi and Trung Rivers. The annual water flow is about 1.46 billion m3, the Cau Son agricultural hydraulic system has been built on the Thuong River to serve irrigation water for Lang Giang district and a part of districts such as Luc Nam, Yen Dung and Bac Giang city.

Fishing on Thuong River (photo: Thien Phong)