Introduction

The Ukrainian part of the delta of the River Danube became a little wilder in 2019 with the removal of ten dams on the Kogilnik, Sarata and Kagach Rivers within the internationally-important Danube Biosphere Reserve.

The River Danube delta, an area of 4,000 square kilometres, is the largest natural river delta in Europe and one of Europe’s greatest remaining wetlands. It covers areas of Romania, Ukraine and Moldova. The Delta contains a large number of diverse habitats, from forests, steppes, waterways and reedbeds, to dunes, lagoons, saltmarshes and beaches. The fauna and flora that live in the Delta are also very diverse with 300 species of birds and over 100 species of fishes, including four species of sturgeons. Most of the world’s pygmy cormorants and the majority of the European populations of white pelicans and Dalmatian pelicans live there.

  • Name: Danube Delta Dams
  • Location: Danube Biosphere Reserve Ukraine
  • Type of dam: Clay embankments
  • Measurements: Heights 1-2.6m, Widths 7-10m, Lengths 30-300m
  • Aim of removal: To restore natural hydrological processes, create new habitat and increase biodiversity
  • Year of removal: 2019

HISTORY

The picturesque Kogilnik and Sarata rivers rise in Moldova and the Kagach River in Ukraine before entering the Sasyk Lagoon in the Ukrainian part of the Danube Delta. The length of the rivers is Kogilnik 243km (120km in Ukraine), Sarata 120km and Kagach 29.5km.

Historically, some fish species probably migrated along these rivers  through the Sasyk Lagoon on their way to and from the Black Sea but, in 1976, the Russians built a 14km concrete barrier which cut off the lagoon from the sea making it impossible for diadromous fish species to pass through. Fish migration may be viable in the future if plans to remove the barrier separating the Sasyk Lagoon from the Black Sea are implemented.

The main reason, therefore, for removing the dams on these three rivers was to restore natural hydrological processes – an unrestricted flow of river water which would lead to the creation of about 20 kilometers of new habitat along the rivers, including flooded meadows. This had the potential to benefit a host of wildlife species including wild carp, frogs, otters and a wide range of breeding and migratory birds. Fishermen could profit from healthier fish populations and it was hoped that the comeback of wild nature would also support new opportunities for nature-based tourism.

Alexander Voloshkevich, Director of the Danube Delta Biosphere Reserve, commented:

This project will benefit a wide range of wildlife, but especially fish. Removing the dams will improve river flow, revitalising local vegetation which serves as a spawning ground. More fish is obviously good news for fishermen.

Enhanced river flow will also increase riverside meadow areas, which should boost local grazing. Last but not least, better natural channelisation will reduce the flooding of agricultural land and a local highway.

From previous experience, the removal of the dams should see wild nature return very quickly. Flooded meadows will become green the following year, providing fertile habitat for spawning fish, large flocks of birds and other animals.

The ten dams were located at the northern end of the lagoon near the town of Tartabunary. They were embankments constructed from clay with heights ranging from 1-2.6 metres, widths between 7-10 metres and 30-300 metres in length.

Map showing the locations of the dams which were removed (nos. 2-11). The gap in dam no.1 was widened during the project. The short yellow lines indicate the position of the clay embankments. The red line is the boundary of the Danube Biosphere Reserve.

The dams were built several decades ago during the Soviet era in order to give easy access to a former sewage plant and other local facilities and to divert fresh water for agricultural irrigation. This scheme did not produce long-term results and the dams were abandoned long ago with no clear evidence of who owned them.

For many years, this series of small, obsolete barriers restricted water flow close to the mouths of the Kogilnik, Sarata and Kagach rivers. This had a negative impact on river beds and local diversity, disrupting the migratory pathways of fishes, blocking sediment transport and causing fragmented habitats. There were also negative effects downstream of the barriers: spawning grounds for fish were cut off, drained meadows dried up, and pastures were subject to salinization – all leading to a decline in biodiversity. Easy access for people and livestock also meant easier access to the islands in between the rivers for poachers, feral dogs and other predators , leading to increased concern for the birds that use the islands for breeding, and the direct destruction of nests and predation of chicks.

The barriers were also in violation of The Water Code of Ukraine (1995) which is the basic document regulating the legal relations in the field of water use.

Embankments nos. 2 and 3 on the Kagach River carrying tracks across the reed-filled water
Embankment no. 5 in the delta of the Kogilnik and Kagach rivers carrying an access road
Embankment no. 6 in the delta of the Kogilnik and Kagach rivers

PLANNING THE REMOVAL AND COST

The idea to remove the embankments was suggested by the management of the Danube Biosphere Reserve (DBR).

These barriers were chosen because:

  • They were all within the boundary of the reserve.
  • This would make the project easy to implement.
  • No lengthy endorsements were needed for their removal from external bureaucracy.
  • Removing the embankments would provide tangible outcomes.
  • The results were expected to be wholly positive for the environment and wildlife.

Local government authorities and the management of the DBR were involved in the decision.

Planning the removals took three years. The idea was first mooted in 2017 during project planning for the Endangered Landscape Programme. The Council of the Danube Biosphere Reserve then adopted a resolution supporting the restoration project which was agreed with local stakeholders. Following this, the proposal was developed and funding sought.                           

The planning process also involved local authorities, such as the local council of Tatarbunary, the small town situated close to where the three rivers enter the Sasyk Lagoon. The council was consulted and gave its approval for the project. A community event will be held in 2020 to inform local people about the benefits of the restoration and the opportunities that these benefits will provide.

Prior to the removals, a study was carried out by experts from the Biosphere Reserve, the local water agency and Rewilding Ukraine to establish the feasibility of, and justification for, removing the dams. The proposals for restoration were summarised in a report: ‘Pre-project justification for the restoration of the hydrological regime of the delta system of the Kogilnik, Sarata and Kagach rivers and the improvement of hydrological connectivity with the Sasyk Lagoon in the Danube Biosphere Reserve’. This document can be found in the archive of the Danube Biosphere Reserve.

The report included survey results and analysis of the landscape and its biodiversity, the history of construction, the impact of the dams and the results of the restoration that were expected after the removals had taken place.

There were no target fish species at this stage as the focus was on restoring the hydrological regime of the area to benefit biodiversity in general including plants, fishes, amphibia, birds and mammals. Fish species that could benefit would be those that depended on the newly-flooded meadows and grasslands, such as wild carp and bream.

The removal process was financed by the Endangered Landscapes Programme and a crowdfunding campaign launched in the Netherlands in June 2018. With a total of 28,000 Euros required for the removal, the aim was to collect 14,000 Euros. Together, however, more than 350 campaign donors contributed nearly 20,000 Euros, with Rewilding Europe and partners contributing the shortfall.

The campaign was co-ordinated by WWF in the Netherlands and was part of a Dam Removal Europe initiative to remove obsolete dams.

Mykhailo Nesterenko, team leader of Rewilding Ukraine, expressed his thanks to the individual donors:

We would like to say a big thank you to all the generous Dutch people who donated to this campaign. Removing these dams will revitalise the river, restoring natural processes, supporting wild nature comeback and underpinning the development of nature-based economies.

THE REMOVAL PROCESS

The dismantling programme was carried out in 2019 by a construction company commissioned by the Reserve. It was originally planned to take place in the summer, when the water level in the rivers was at its lowest and the wildlife breeding season was over, but was eventually carried out in the autumn as technical preparations had taken longer than expected.

Dams nos. 2 – 11 were removed over a period of only three weeks. After removal, gaps of around 10 metres wide had been created in the embankments allowing the rivers to flow freely.

Dam no. 1 was also a complete embankment when the project started but, as planning for the removals progressed, local fishermen breached this dam themselves to let fishes pass through. Newly-flowing water enlarged the gap and, during the removal of the other dams, the gap was made significantly bigger by project staff. During the second phase of restoration, it might be widened even further.

Dam no. 1 with the original breach made by local fishermen widened by the effects of flowing water
A digger works to enlarge the gap in dam no.1
Dam no. 1 at the end of the dam removal project with the gap widened even further

Mykhailo describes the removal process:

It was relatively easy in terms of knocking the earth off the dams. The main difficulties were about access and moving heavy machinery around the alluvial floodplain. The excavator got stuck at one point.

The major difficulty for the project was to do with the management of material taken from the dams. We had to deposit it as a thin layer on the soil or at a secure location where it would not get washed back and clog the river channels. Transporting it elsewhere was far too expensive and would include a lot of work by machinery and using specific dump sites.

Partially-collapsed embankment no. 7 in the delta of the Kogilnik river

EFFECTS OF REMOVAL

Mykhailo continues:

Its still too early to judge or measure the impact. The removals were finished in December 2019 in very dry conditions which still persist in the region. Its probably the hottest and driest winter on record. With hardly any significant snow or rainfall over this winter, the whole lower Danube and south Ukraine were suffering from drought. This is why we even delayed a press tour last year as the site was rather dry and the effects of removal were not easily visible. A month later, after the rain had started, the area got nicely flooded.

The main results are due to manifest in spring 2020 when the meadows will be flooded and fish spawning will start. We are planning several visits and the press tour to highlight the results.

There is no specific monitoring for target species but general monitoring of the biodiversity for species composition, for example, takes place as a part of the regular monitoring on the Biosphere Reserve.

POSTSCRIPT

Although these dams have been successfully removed, this is not the end of the story for the three rivers and the Sasyk Lagoon. Removal of these dams was only the first step in the restoration of this wonderful habitat. In 2020, the project will enter its second phase, when feasibility studies for upriver channel clearance and restoration will be conducted. There is also a chance that the Sasyk Lagoon itself, a habitat severely changed by anthropogenic interference, will be reconnected with the Black Sea.

Mykhailo explains:

In spring 2020 there will be an independent assessment of the results of removing the dams. This will include a scoping survey for further restoration of these rivers upstream. Funds are still available at Rewilding Ukraine to further restore these rivers. However, the areas upstream are outside of the Danube Biosphere Reserve and approval will involve a wide range of stakeholders and, probably, more complicated consultations.

The main restrictions on upstream restoration will be the privately-owned property and farmland. The feasibility of further restoration overlapping with private property will be clear in 2020.

Re-establishment of the larger Sasyk Lagoon system has been debated for more than a decade. Last year there seemed to be a political decision to restore this large marine lagoon into which the Kogilnik, Sarata and Kagach rivers drain. The Sasyk restoration will be a huge project – several research institutes have already started research on the feasibility of this restoration with state funding. Should it be viable, further co-operation may be developed with local communities and authorities for the restoration of the lagoon.

Mykhailo Nesterenko has seen the negative effects that these barriers caused and also watched as the old dams on the Kogilnik, Sarata and Kagach rivers were demolished:

Its great to see these rivers flowing freely once again. For many years these obsolete dams had a detrimental impact on fish populations, other wildlife and people. This removal project, which will aid our rewilding efforts in the Delta significantly, serves as a role model for other outdated dams across the Delta and Ukraine.

The experience is being used by the management of the regional water authority, which was involved in our project, to assess the practicality of dam removal on the Yagorlyk river in the north of the Odessa region. There the feasibility and the technical project document is being developed with much support from the local communities and the involvement of our team.

My main message is that dam removal is possible with a fairly limited budget, at least on small rivers. The dams and infrastructure on these rivers may not be very heavy and physical removal may be done relatively easily. Crowd-funding or local fund-raising may generate enough resources to do this if the local communities and landowners support river restoration. The main benefits include those for biodiversity and water quality, the latter being particularly important for local communities.

With special thanks to Mykhailo Nesterenko and Kateryna Kurakina at Rewilding Ukraine for source information.

Photos taken by Maxim Yakovlev.

Further interesting information about the Sasyk Lagoon can be found here:

https://www.rferl.org/a/ukraine-sasyk/30101468.html

https://pulitzercenter.org/reporting/failed-soviet-irrigation-project-brings-eco-apocalypse-sw-ukraine