太原省
The Thac Huong Irrigation Scheme in the Yên Thế district, adjacent to Thái Nguyên Province and west of Hanoi, was implemented in early 20th century by the-then French colonial government. Construction of the irrigation scheme for utilization of the Cầu River was started in 1922 and operationalised in 1936. The irrigation system was built on the left bank of the river and envisaged irrigation to a total command area of . Net irrigation provided was to an area of in Phú Binh (Thái Nguyên province), Việt Yên, Tan Yên, and Hiệp Hoà (in Bắc Giang Province). Additionally, a supply of potable drinking water was built into the system. Navigation was part of its beneficial uses as a transport route for shipment of rice and salt from Hai Phong to Thái Nguyên. The scheme, as built, has a concrete dam of height and length, known as the Thac Huong dam across the Cầu River. A head regulator on the canal is in width and in height. 10 branch canal intakes were provided, each with a capacity of 25m3/s. However, the energy dissipation arrangements of the dam have been damaged, several times since it was built, by floods and bombing raids. The Asian Development Bank (ADB) funded the rehabilitation project in 2000. Although restored after 1955, the project is facing water shortages and is unable to meet the demands for irrigation due to building of many projects in the upstream reaches of the river, over utilisation by industries and poor maintenance. Transbasin diversions have been implemented along with pumping from other streams to meet the water demands for irrigation and other uses of drinking water and industries.