Azmak Hydropower Project

The biggest and the first rubber dam application in hydroelectric projects in Turkey.

Project Information

Client: BM Holding

Location: Ermenek

Status: Completed


Key Features

Total Installed Capacity 25 MW

Run-of-River Type

Rubber Dam

1000 m3/s Spillway Capacity

Semi-Indoor Powerhouse

S-Type Kaplan Turbine

Long Riverbed Excavation 



Azmak-I HEPP, Azmak-II HEPP and Kirpilik HEPP are run-of-river type hydroelectric facilities which were constructed over the Ermenek River. They are placed from upstream to downstream as Azmak-I HEPP, Azmak-II HEPP and Kirpilik HEPP respectively and they started to be in commercial activity in 2010.

In the upstream of these projects, Gezende Dam and HEPP which was put into operation in 1991 and Ermenek Dam and HEPP which is the highest dam of Turkey with its altitude of 218 m are located. Although there are two reservoirs in the upstream, the spillway structures were designed to be able to evacuate a high flood discharge of 1,000 m3/s since the Ermenek River has a huge flood potential.

Azmak HEPP

Azmak HEPP

Rubber Dam

The most important characteristic of these projects is that they all have rubber dam, 5 m in height and 48 m in width which make them the biggest and the first time used in hydroelectric projects rubber dam application in Turkey. Usage of rubber dam as the control mechanism of spillway eliminates the need for twelve steel gates with the dimensions of 5 m x 4 m and their reinforced concrete piers, which results in savings in the first capital and operating costs. All application projects and detail solutions of these rubber dams were prepared by Prosem Engineering.

S-Type Kaplan Turbine

Since the head is low and the flow is high for all three projects, S-type Kaplan turbines were installed for the first time in Turkey.

Riverbed Excavation 4.500.000 cu.m

The riverbed levels at the downstream of the projects have been lowered up to 5 m resulting a drop in tailwater levels. In this way the amount of agricultural lands laying under water is reduced and the negative social effects and expropriation costs are minimized.

Foundation Design

In the projects the spillways and RCC body were directly placed on alluvial ground. The foundations of the structures are designed in such a way that there is no need for soil improvements causing extra costs.