Saving St. Pete From the Floods
- By Irina Titova
- Oct. 04 2010 00:00
The dutch know a lot about dams. And it was to them that Russia turned to when they needed help completing a dam for St Petersburg.
St. Petersburg was built to give Russia access to water from the Gulf of Finland, but the imperial capital has seen that water as both a blessing and curse. More than 300 floods have hit the city over its history, with water levels reaching as high as three meters, as waves intermittently wash in from the Baltic Sea. It is only now, after the completion of the St. Petersburg Flood Protection Complex, that the city is finally safe from its surrounding waters.
The most famous flood to hit the city was in 1824, where more than 500 people were killed, prompting playwright Alexander Griboyedov to write that "the embankments of the various canals had disappeared and all the canals had united into one. Hundred-year-old trees in the Summer Garden were ripped from the ground."
It was a flood in 1955 that pushed the Soviet government to consider protecting the city with a dam. That was only two years after a flood devastated the southwestern part of the Netherlands and sparked the construction of a system of dams and barriers called the Delta Plan, which have been compared in their complexity to the mission to send man to the moon.
In St. Petersburg, construction finally began in the late 1970s. The plan was to build a 25-kilometer dam complex that would curve around the Neva Bay to protect the city from the gulf beyond but it was halted in the late 1980s because of ecological worries and a lack of funds. It was only in the last decade that the experience from those Dutch floods has allowed the city to move toward the completion of its great dam project.
In 2001, the Dutch government, along with the European Bank of Reconstruction and Development, sponsored initial research into the possibility of reviving the plans for the dam's construction.
The Dutch government and EBRD made "a valuable contribution toward resuming the dam construction," said Oleg Panchuk, deputy general director of the Flood Protection Barrier Complex.
"They significantly helped resume works by giving the grants for the research. The help came right at the time when the Russian government decided to renew the project," Panchuk said.
The barrier, which can cope with water levels of up to 4.5 meters high. can close within thirty minutes of an alarm signal, completely protecting the northern capital.
Meteorologists warn of a possible flood 48 hours and then 24 hours beforehand. Meteorologists and dam workers keep a close eye on the water level in the final 24 hours and if it looks set to rise 1. 60 meters above the norm, the dam is closed.
Two Dutch companies, Royal Boskalis Westminster N.V. and Royal Haskoning, have played a huge part in the development and construction of the 109 billion ruble ($3.5 billion) flood protection barrier complex.
"After 300 years, the city founded by Tsar Peter that had suffered devastating floods every year since its inception is finally safe," said Boskalis project director Pieter van Vuuren. The flood protection complex begins at one side of the Gulf of Finland and then meets up with Kotlin Island, where the fortified town of Kronstadt is located, before heading across to the other side of the gulf.
The complex includes 11 dams, water passing facilities that allows gulf water to go back and forth in measured quantities, two ship-passing facilities that also work as flood gates and a six-lane automobile road with bridges, a tunnel and transport interchanges that stretch across the dams. The barrier can cope with water levels of up to 4.5 meters, completely protecting the northern capital.
The most famous flood to hit the city was in 1824 when hundreds of buildings were simply washed away and more than 500 people killed.
"It's no secret that the Dutch are ahead of all the planet in construction of flood protection facilities, especially those meant to stop stormy waves," said Panchuk. "It's a fact that there are some work processes that nobody in the world can do better than them at the moment."
Dutch companies were also able to offer to do the job quicker, which "made it obviously cheaper," said Panchuk.
Completion of the Barrier has saved the city over $100 million every year in potential flood damages, said Alexander Boutovski, Haskoning's senior consultant and business development director for the Coastal and Rivers Division in Russia.
Boskalis signed a landmark 58 million euro contract in 2006 to build the 14-kilometer long Kronstadt Shipping Channel, replacing an older channel that had far too many turns as it connected to the new barrier.
"[They] made it much deeper than the old one. Thus, if the old fairway was 12 meters deep, the new one reached 16 meters. Such depth allowed more large ships to enter the area of the city," said Panchuk. This was followed in 2007 with a contract, together with German partner Hochtief for the completion of the dam and the construction of a southern ramp and tunnel.
Boskalis has a 60 percent share in the 350 million euro contract with Hochtief.
The dam will form a section of the six-lane Ring Road around St. Petersburg, with a tunnel running underneath the new shipping canal.
Both operations required a huge amount of technical expertise and experience. Worries about environmental damage to the fragile ecology of the Neva delta had to be taken into account and there was also the significant problem of unexploded WWII mines in the area. And the n there were climate problems.
"The operations were not always easy," Van Vuuren said. "During the construction of the last part of the dam, we encountered many days with bad weather causing the water level to rise over our low, small dam in progress. Still, these high waters made it evident that the barrier was an absolute necessity."
The city of St. Petersburg is safe from flooding now, although final work by Boskalis on the flood barrier complex is ongoing as the transport tunnel under the dam is being finished. Project completion is scheduled for April 2011.
Royal Haskoning has provided engineering and consultancy services for almost a decade on the flood protection complex. The company led the Technical Feasibility Study of the flood protection complex project in 2002, and took active part in the Environmental Impact Assessment and the Costs Recovery Study.
Some of their most important work involved consulting on the construction of the flood gates for St. Petersburg's main sea navigational channels.
These gates allow shipping traffic to and through the barrier to the St. Petersburg port, which is used by both cargo ships and tourist cruise ships.
The major initial technical difficulty was the fact that work on the flood protection barrier had been frozen for almost 15 years, said Boutovski.
"At first, the designers thought that at some stage it would be enough just to clear old structures and carry out some repair work, but then it turned out there was a lot more to be done," he said.
One of the advantages of working on the complex was that it was such a high profile project. Some say that Prime Minister Vladimir Putin, a native of St. Petersburg, was the reason the complex was revived.
"It is followed carefully by the highest officials in the country," said Boutovski.