The Ilisu Dam – Environmental Impacts

Every dam causes some impact on the environment. Whether its purpose is hydroelectricity production, flood control or irrigation, a dam is, after all, a barrier across a river – a very concrete obstacle to the river’s natural course and functions.

For many years now, campaigners, local affected communities and scientists have catalogued the many ways in which dams interfere with the ecosystem. The more immediate effects are obvious – the loss of lands, farms, forests and valleys to the dam’s reservoir. Three hundred square kilometres of land are to be flooded behind the Ilisu dam.

A dam also regulates the flow of the river, controlling the release of water according to electricity production or irrigation needs. A river downstream of a dam can be severely depleted of water, a mere trickle of what it once was. The Ilisu has the capacity to restrict severely the Tigris’ flow to downstream Syria and Iraq.

Other impacts of dams may be less obvious but nonetheless destructive. Dams trap not only rivers but the contents of rivers – the load of nutrient-rich silt and sediments picked up and deposited by the river as it flows over lands. This build-up of sediment behind a dam can not only interfere with the dam’s function (for example, by decreasing the level of ‘useful’ water in the reservoir as sediment builds up on its bed) but also deprive the river below the dam of silt, thus lessening the fertility the river can bring to agricultural lands downstream.

Although Balfour Beatty, the UK company heading the construction consortium, says of that sedimentation of the Ilisu dam will cause "no problems", their claim is extremely doubtful. For a start, Hydro Concepts Engineering, the authors of the project’s Environmental Impact Assessment (EIA), were unable to present any reliable data on Ilisu’s sediment risk. They told the Swiss campaign group, Berne Declaration, that they estimated the annual sedimentation load of the Tigris at 15 to 30 million cubic metres. This would fill up 10-20 per cent of the reservoir’s operating capacity within 50 years. And yet the authors of the EIA expect the reservoir to be useful for 80-100 years.

Dams can also affect the quality of the river water – both above and below the dam. They can concentrate pollutants, deplete or increase oxygen levels, alter the river’s temperature. All of these impacts alter the lives – human, animal and plant – the river feeds.

The issue of water quality is a very grave concern in the case of the Ilisu dam, one that even Balfour Beatty acknowledges. Currently, the solid waste and wastewater of major regional cities such as Diyarbakir (population over 1 million), Batman and Siirt flow into the Tigris without even primary treatment. It is reasonable to assume that the Ilisu dam’s reservoir will vastly reduce the ability of the Tigris to purify itself. This will jeopardise water quality and potentially cause major health problems in the major towns, where the infrastructure has already been stretched beyond endurance by the influx of Kurds forced from their rural homes. According to the Berne Declaration, two of the companies in the construction consortium, Sulzer and ABB, regard this as "one of the most important project risks".

Balfour Beatty acknowledges that the city of Diyarbakir and the towns of Batman and Siirt "at present have inadequate sewage treatment facilities" but argues that Diyarbakir, the main offender, has "already embarked on new construction". It also states that an undertaking is "being sought from Government of Turkey that new treatment plants for Batman and Siirt will be built in due time." Would this be an undertaking to the consortium, and would it be legally binding? It is not yet a matter of public knowledge whether binding decisions to finance and build these plants have already been taken or whether the plants will have a sufficiently positive impact.

There are also major concerns of health risks to the local population. According to the Berne Declaration, the Ilisu reservoir will "infest the area with Malaria and Leishmaniasis". The latter can cause anaemia, fever, dysentery and pneumonia – and may even be fatal. Such diseases flourish when a large body of water – the dam’s reservoir – stagnates as the plant life it has flooded rots, helping to create a breeding ground for unhealthy organisms.

Failure to Release the Environmental Impact Assessment

The EIA for the Ilisu was commissioned in late 1997 by Sulzer Hydro and completed by spring 1998 by a team of consultants headed by Hydro Concepts Engineering. Neither the original EIA nor any proposed mitigation measures have yet been released to the public. Requests by Swiss and UK NGOs for access to the documents have been consistently turned down. In Britain, a request by Friends of the Earth UK in June 1999 to the Department of Trade and Industry for the release of the EIA was refused on the grounds that the report did not belong to the UK government and was not therefore its property to release.

Balfour Beatty only acknowledges a few of the Ilisu dam’s potential impacts. These include resettlement, the impacts of the dam on the water rights of downstream users, the preservation of cultural heritage, water quality and waterborne disease. The many other potential impacts of the dam it ignores. According to Balfour Beatty, the EIA undertaken by Hydro Concepts "confirms that there are no problems as regards the potential effects of the project on local flora and fauna, climate, landscape, ground water, earthquake risk, flooding risk, sedimentation or erosion."

Here is the problem. Balfour Beatty can make claims about what the EIA does or does not say about Ilisu’s impacts, but the public has been denied access to the EIA. So while the EIA has not been released, such claims are hollow, as it is impossible for them to be tested, subjected to independent scrutiny or even to assess what would constitute ‘a problem’.

Even without access to the EIA, however, it is clear that the Ilisu – as a large dam in a fragile environment – carries grave risks to the environment and to the people who live in it.