Not always, but the majority of the time they are filled. It is best once a tunnel is filled with water to minimize the number of times it is emptied from an engineering stand. AGL will periodically empty a tunnel for inspection over the course of the project, but as a general practice keep the tunnels full.
In general terms the flow downstream of the dams will be reduced, however each dam structure has an environmental flow release that is maintained at all times. This ensures there is a constant release of water 24 hours / day, 365 day per year. During high flow seasons (rainy seasons) there may be times when additional water is released from the dams beyond the environmental flow.
Didachara dam is 52 meters, and Skhalta dam is 18 meters.
Each reservoir has a “tunnel intake” structure that is gated and the location where the water enters the tunnels. When the water rises in the reservoir and the intake gate is open, water naturally flows into the tunnel due to the incline.
Water release beyond the environmental flow at each dam location will occur primarily during two events: 1) Flushing: The times when the gates at the dam are opened to flush sediment downstream, and 2) High Inflow: Times when the amount of water entering the reservoir exceeds the capacity of the reservoir and water needed for power generation. The flushing is planned to take place during these high inflow times, which is anticipated to be approximately in spring (March/April). AGL will share this with the municipalities in advance and as well will sound alarms on the dams when gates are opening.
In general terms the water levels in the riverbed will rise 1-3 meters above normal levels (environmental flow levels) but should be within pre-dam river levels. Downstream water levels during release are not expected to rise to structures along the riverbank.
Different components of the power plant have different lifespans; moving parts in the turbines and generators have more wear and will need to be replaced more frequently. Civil structures including dams, tunnels, and buildings are designed for long-term life spans (50+ years). All structures will be monitoring on a fixed schedule throughout the project.
Both in Georgia and Turkey.
The intention of the Shuakhevi HPP is to provide more reliability to the national grid. With additional power generation in Georgia the amount and duration of outages (periods with no power) should reduce, thereby having a more reliable supply of power to customers. Power tariffs are set by the government.
Throughout the year, solid sediment accumulates in the reservoir, which settles in the reservoir over time, this is called siltation of the reservoir. In order for the reservoir not to lose its useful volume of water (the volume needed to generate electricity), it is necessary to wash the reservoir periodically. In particular, in spring, during the period of water abundance, the sediment accumulated in the reservoir will be flushed by opening the sluices on the dam and the flow will be carried out downstream. During the flushing of the reservoir, water is not supplied to the diversion tunnel, and the flow of the river will be carried downstream in its full volume. At this time, the HPP is temporarily stopped, and no electricity is generated. It should be noted that Skhalta and Didachara reservoirs are flushed step by step, in the first stage the Skhalta reservoir is flushed, and then Didachara, intervals vary from 4 to 5 days.
How much water will be released downstream, it depends on the natural inflow of the river. During flushing, the water level in the river will rise, but it will not exceed the natural inflow level of the river. Our company conducted hydraulic survey of river Skhalta, the purpose of which was to reveal the riverbed and flood heights at different flows in the river, from 20m³/s to 100m³/s. However, during flushing generally, 40 to 50 m³/s is released .During the survey, those plots of land that are in the risk zones of natural flooding were also identified. As a result of the survey, it was established that the increase in the water level of the river caused by the flushing of reservoirs from the sediment does not have a significant impact on the flooding caused by natural, seasonal water level of the river.
In addition, before each flush, we carry out a drone survey of both valleys within 5 km of the dam to reveal the pre-flushing condition and then assess/react to the impact of the flush.
From 2013 AGL has been conducting monitoring of river habitats, mainly fish, macroinvertebrates and mesohabitat surveys, which will continue regularly during operational phase. Local and international experts are involved in reviewing and interpreting monitoring data. In case monitoring reveals any impact, specific and robust mitigation measures will be implemented by the company, which will ensure to achieve no residual adverse effects to biodiversity. With all mitigation measures successfully implemented, the project is not expected to cause significant irreversible damage to the local ecosystem over the long term.
The needs of the water users downstream of the dam have been considered and the environmental flow has been prescribed by the Government of Georgia (GoG). The environmental flow will be released, and the flow figures are submitted to the GoG and disclosed on the website.
AGL has already planted 2,700 red listed trees in the Vashlovani and Dachara villages in Khulo municipality to compensate forest affected by project footprint. The company is working closely with the Adjara forestry Agency to find additional land for compensatory planting. In case additional land for compensatory planting cannot be secured, AGL will provide financial compensation to Adjara forestry Agency to conduct compensatory activities on behalf of AGL. This is still being negotiated with the national and local authorities, landowners, and stakeholders.
The land used for spoil disposal is owned by AGL and is to be used exclusively for the project purpose. Additionally, AGL is obligated to restore the area and monitor rehabilitation for 2 years, after which the company will return the land to state.
Hydropower is clean, renewable energy. There is no risk of river pollution during dam operation. AGL will undertake water quality monitoring regularly for necessary parameters.
In practice worldwide, in order to minimize the impact on the ichthyofauna (fish, macroinvertebrates, associated hydrofauna) during the reservoir flushing, a number of measures are being implemented, which are actively used by Shuakhevi HPP, namely:
1. Environmental (fish, macroinvertebrates, water quality characteristics, turbidity) monitoring is carried out before flushing, during actual flushing and after flushing, the purpose of which is to assess the forms and extent of the impact of flushing on environment and to develop appropriate recommendations, even if temporary suspension of flushing will be required if critical results will be released during monitoring.
2. Flushing will be completed before the beginning of the period of intensive fish spawning, thus minimizing the negative impact of flushing on the reproduction of ichthyofauna;
3. Shuakhevi HPP reservoirs will be flushed separately and not together, with minimum intervals of at least 5 days, in order to avoid the cumulative impact of flushing on the river Adjaristskali and the confluence of Shalta river, and even downstream.
4. Flushing of reservoirs will be carried out during the spring flood period, after one of the stages of the spring flood, thus minimizing the negative impact on the ichthyofauna, because at this time the fish have already moved from the areas of active flushing to the less risky areas of flushing;
5. Flushing of reservoirs will be carried out annually in order to avoid the accumulation of large amounts of sediment in the reservoirs and accordingly reduce the scale of the impact of the flushing process.
Yes. AGL has developed Operational Phase CSR Strategy for four years. This document has been approved by the Board of Directors. The document envisions continuation of social programs within AGL’s CSR efforts. The company identified support of long-term economical development of the region as a main focus of its CSR programs during the operation phase.
During the operations phase most of the workers have a technical mechanical and/or electrical background. These employees are responsible for operating the plant and doing ongoing maintenance on the plant during operations. Additionally, there will administrative work including accounting, government compliance, and other administrative tasks.
The Company pays all taxes which are applicable by the Georgian Tax Code, these are: income tax, revenue tax, VAT, and property tax. The latter is paid directly to the municipal budgets.
Flushing of reservoirs is carried out taking into account the requirements of international banks and the environmental norms established by the legislation of Georgia. Before each flushing, the works are agreed with the state electricity system of Georgia. To ensure the safety of the population, the company implements the following measures:
- Before each flushing, the company provides written notifications and also holds informational meetings with representatives of the mayors of local municipalities (Khulo, Shuakhevi and Keda), community representatives, as well as representatives of the police, fire and rescue services.
- Informational meetings are held with the population living downstream the dams, teachers and students of educational institutions located near the river bed.
- 15 minutes before the water release and also immediately during the water release, warning sirens are activated
- The company placed safety signs in the vicinity of the hydroelectric station, near the bridges and crossings. Residents must be careful and follow safety rules.
Note that the water level in the river will rise during the release, but will not exceed the level that existed in the river bed prior to the project. It is not expected that water will overflow from the banks of the river during the water release.
No, fishing is strongly prohibited in dam and reservoir areas for safety reasons.
No. Swimming in the reservoir is not allowed. Water levels will rise and fall approximately 10 meters and it is dangerous.
Some areas of the Didachara reservoir where slopes are very steep will be fenced. Local population should be very careful and watch out that their cattle do not fall in the reservoir.
Our company actively cooperates with the Emergency Management Agency of Adjara. The agency is the first point of contact during an emergency. In case of any emergency, you should contact the agency on 112.