Angutlu I - II Hydropower Projects

To reduce waterhammer effect “Pressure Relief Valves (PRV)” are installed in the power house instead of building a surge tank.

Project Information

Client: Turkerler Construction

Location: Giresun

Status: In Progress


Key Features

Diversion Type

Installed Capacity 24 MW

Power Tunnel

Transient Analysis

Pressure Relief Valve

Flap Gate




Angutlu I - II Hydropower Projects are cascade hydropower schemes which are located in Black Sea Region within the border of Dereli district of Giresun province over the creek of Aksu. Angutlu–I weir has a catchment area of 722 km2 along this river and diverts water to Angutlu–I HEPP whereas Angutlu–II weir with a catchment area of 782.00 km2 diverts water to Angutlu–II HEPP.

Both projects have a similar formulation in that in both projects the flows taken by water intake structures are conveyed through power tunnels to the power plants that contain two big and a small Francis type turbine. Angutlu-II weir which is located at the downstream of Angutlu-I HEPP and near the city center of Dereli is designed for Q500 flood discharge of 680.94 m3/s by installing five units of 8.0 m width flap gates on the spillway.

In Angutlu I - II Hydropower Projects w rhich are located in close vicinity of the city center where bulding stock has a considerable density, the conveyance lines are planned as pressurized tunnels taking the probable expropriation costs into consideration. Since the flows are transmitted directly to the powerhouse via energy tunnels, there was no more need for constructing a forebay and penstock. Besides, to reduce waterhammer effect “Pressure Relief Valves (PRV)” which ensure savings both from cost and space are installed in the powerhouse instead of building a surge tank. In this manner, the negative environmental effects and construction and expropriation costs are reduced to the least possible extent thereby ensuring the smooth and rapid construction of the project facilities. The transient analysis related with the waterhammer effect and adaptation of the PRVs to the system are also carried out by Prosem Engineering.