Saint Petersburg flood protection barrier

The challenge: protect St. Petersburg from increasing flood risks

On top of annual flooding, Saint Petersburg has experienced historical floods of up to 4.2 metres above Baltic Sea level. If this magnitude of flood happened again, it would lead to significant capital damages, city disruption, environmental damage, and even loss of life. As global temperatures rise, statistical analysis has also shown that flood frequency and height are increasing too.

The Soviet Union began trying to protect the city in the 1970s, with a plan to construct a 25km-long barrier including openings for navigation and river water discharge. Construction began in 1980, but ceased seven years later due to funding problems and concern over the barrier’s impact on pollution levels.

In 1990, after several environmental studies, an International Commission found that the barriers impact was environmentally neutral – and it should be completed. The Russian Federation then entered talks to obtain funding from the European Bank for Reconstruction and Development. To achieve funding, it needed to prove a sound, technical, economical, and environmental basis for the barrier.

The solution: comprehensive design, engineering, and construction plan for St. Petersburg flood protection barrier

After successful consultancy on another water-related project in Saint Petersburg, Royal HaskoningDHV was contracted to take a lead on the feasibility studies and economic and environmental analysis for the barrier. 

In 2001-2002 we carried out a technical feasibility analysis and an environmental impact assessment. These studies also included a review of the state of the barrier after work had been suspended for 15 years. 

We also defined the scope of work for rehabilitation and completion, undertook planning and costing of works, and conducted a strategy and project implementation plan – all completed within time and budget.

In 2003, we were appointed as part of a consortium to update the design, prepare engineering design and tender documentation, and provide designer's supervision during construction. 

This included: 

• Design review
• Advanced numerical modelling of waves and currents
• Physical scale modelling of floating sector gates
• Design of floating sector gates
• Design of a 5 km long dam section
• Design of a tunnel under the main navigation opening

In a separate contract we, along with local partners, also provided contract management and construction supervision.

The result: a robust defense system against storm surges and flooding for the city

Our studies recommended the Saint Petersburg flood protection barrier should be completed. And they provided the basis for a subsequent loan agreement between the European Bank for Reconstruction and Development and the Russian Federation.

The studies found that fairly extensive upgrading works of the existing structures were required and that the design of some important elements of the barrier – like the gates of the main navigation opening – needed to be adapted to guarantee safe operation.

Since 2003, we have been involved in the implementation phase of the project alongside Russian design institutes. In this phase, our work included design studies and the preparation of detailed designs, the preparation of tender documents, evaluation of tenders, management of contractual interfaces, and supervision of construction.