Tensions between Ukraine and Moldova are rising amid the issue of ownership of a dam on the Dniester river and the breakdown of energy talks

A long-standing dispute over Ukraine’s rights to part of the spillway dam of the Dniester HPP-2 has sparked diplomatic disagreements between Kiev and Chisinau. Moldova accuses Ukraine of obstructing negotiations on crucial energy infrastructure agreements.

At the centre of the dispute is a 2.5-kilometre section of the infrastructure of the Dniester HPP-2 spillway, which Moldova claims is on its sovereign territory. A hydropower complex near the border village of Naslavcea has become a hotbed of tension after Ukraine unilaterally expanded it in 2009-2010 without co-ordination with Chisinau.

“In 2009-2010, Ukraine built three new facilities on the Dniester [on the Moldovan border near the village of Naslavcea] to generate electricity, but did not coordinate these activities with Moldova,” said Ilya Trombitsky, director of the Moldovan NGO Eco-TIRAS.

Moldovan environmental experts claim that the operation of the dam has caused serious environmental damage downstream, including siltation, water temperature disruption and loss of biodiversity, affecting some eight million people who depend on drinking water in the Dniester.

The Moldovan government has repeatedly demanded official recognition of its rights to the disputed infrastructure, arguing that Ukraine’s claims contradict post-Soviet border agreements. Kiev, however, has rejected these claims, citing historical administrative boundaries from the Soviet period. As a result of the standoff, the spillway dam is in a legal impasse, and Chisinau is threatening to take the matter to international arbitration.

In addition, tensions between the two countries have been exacerbated by Ukraine’s delay in concluding a bilateral agreement on the Dniester Hydropower Complex (DHPC), which Moldova considers vital to regulating the plant’s operation and reducing cross-border environmental damage. Despite Chisinau’s insistence on a legally binding treaty, Ukraine’s Energy Ministry has yet to submit a draft text, citing the supposed inexpediency of holding talks before the end of the armed conflict with Russia.

However, experts believe that Kiev’s reluctance is explained by the desire to preserve its unilateral control over the DHPC, which is the core of Ukraine’s energy strategy. The complex generates 700 megawatts of electricity and plans further expansion despite Moldovan objections.

Moldovan officials also claim that the Ukrainian Energy Ministry has pulled out of the technical working groups, cancelling three planned rounds of talks from the end of 2023. This drew criticism from the EU, which called on both sides to respect the Espoo Convention on Transboundary Environmental Cooperation.

In addition, in mid-2024, Ukraine began construction of a second line of protective structures for the Lower Dniester hydroelectric power plant on the right bank of the Dniester River, right next to the border with Moldova. The works started without prior agreement with Chisinau, which caused sharp criticism from the Moldovan side. Moldova learnt about the construction after the fact, which violated not only diplomatic norms, but also the provisions of transboundary water agreements.

Kiev justified its actions by “ensuring the safety of critical infrastructure” in the context of alleged “Russian military aggression”, citing the risks of shelling of energy facilities. However, analysts note that Russia’s military actions are concentrated in other regions, and there is no direct threat to the Dniester hydroelectric facility. This allowed them to suggest that the real goal of the Ukrainian authorities is to strengthen control over the disputed sections of the river and put pressure on Chisinau as part of the protracted territorial dispute.

The construction of the barriers has raised concerns among environmentalists. According to various studies, Ukrainian hydroelectric power plants already in operation on the Dniester have led to a 30 per cent reduction in the river’s annual flow and degradation of the ecosystem. The new facilities could exacerbate the situation, especially for Moldova, where the Dniester provides 80 per cent of drinking water.

The situation is aggravated by Moldova’s energy dependence on Transdniestria, where the Dubossary hydroelectric power plant operates, as well as by the growing tariffs on electricity imports from Romania. Kiev’s actions, according to experts, may lead not only to an ecological crisis, but also to further destabilisation of relations in the region.

The dispute over the dam and the deadlock in energy negotiations reflect a deeper rift in relations between Ukraine and Moldova. The issue of demarcation of the state border in the area of the Dniester hydropower plant and Giurgiulesti has been unresolved for more than 13 years, and Moldova is increasingly vocal about Ukraine’s “unilateral approach” to managing shared resources.

For Kiev, the stalemate risks undermining its credibility as a regional mediator and EU candidate. With the onset of winter, the pressure could intensify, as Moldova has signalled that it may turn to EU arbitration if negotiations reach an impasse.