Pump It Up

/ by Ted O'Callahan /

How to stop Venice from being swallowed by the sea.

Venice, unflooded.  Credit: Pauline Vos

Venice is sinking beneath the sea. But a group of engineers believe that sea water, itself, may be the best way to save the city.
Giuseppe Gambolati heads a team of researchers who, last month, presented city leaders with a proposal to inject sea water into an aquifer deep below the city. He predicts this will raise the ground level as much as 30 cm over the course of 10 years.

Gambolati has worked on land subsidence issues for 30 years and he says that the technique has been used effectively in other places where the ground has begun to sink. He cites Long Beach, California, where subsidence (sometimes 9 m deep) resulted from oil production; they’ve been using water injection successfully since the 1950s.

A hundred years ago, high waters flooded the Venice’s central square only a handful times each year. John Keahey, author of the book Venice Against the Sea, says that city residents have traditionally felt that the occasional flooding was just a part of life in the Italian city. 

“The water comes and the water goes,” Keahey said. “They will happily put on their boots and trudge through.”

But the issue has gotten much worse in the last 50 years. In 1966, there were 99 major floods; most years now see at least 40 acqua altas (literally, “high waters”).

To compound things, the ocean level is rising. The Adriatic Sea around Venice is 11 cm higher than it was 100 years ago. That’s in addition to the 12 centimeters of subsidence over the last century, much of it due to pumping fresh water out of aquifers.

Gambolati says that the solution is to reverse the process.

“Pumping water in is the same as pumping water out, with the effect reversed,” he said.

According to Gambolati’s team, if Venice had been just 30 centimeters further above sea level, 94% of the acqua altas since 1910 would have been avoided.

In 2003, Italian Prime Minister Silvio Berlusconi set in motion an operation named MOSE, after Moses’ parting of the Red Sea. The project, scheduled for completion in 2011, will place mobile barriers across all three openings of the lagoon that protects Venice from the Adriatic. Hidden most of the time, the barriers would be raised to block the highest tides and storm surges.

The initial price tag for MOSE ws $3 to $4 billion, but it is now expected to cost $6 billion. The mayor of Venice is calling for cost-effective alternatives.

Gambolati’s project is budgeted at $117 million, but he sees it as a complement to MOSE, not an alternative. The engineers would be drilling a series of 12 vertical wells to depths of 650 to 800 m. The researchers say that the brackish aquifer of water-saturated, sandy material is a promising repository for the sea water injection because it is sealed above and below by layers of very low permeability. Roughly equivalent to the pneumatic cushions of some sneakers, the pressure created by pumped water forced between the sealed layers would allow Venice to be raised on a cushion of water. 

While skeptics are concerned that raising the city unevenly will damage Venice’s buildings and structures, Gambolati says satellite technology will allow continuous real-time monitoring, permitting engineers to calibrate the injection rate to keep the lift balanced.

Keahey says the project has many obstacles to overcome, but he added, it is the first time somebody of Gambolati’s stature has brought forward such a detailed proposal.

Originally published December 12, 2005

Tags development engineering research

Share this Stumbleupon Reddit Email + More


  • Ideas

    I Tried Almost Everything Else

    John Rinn, snowboarder, skateboarder, and “genomic origamist,” on why we should dumpster-dive in our genomes and the inspiration of a middle-distance runner.

  • Ideas

    Going, Going, Gone

    The second most common element in the universe is increasingly rare on Earth—except, for now, in America.

  • Ideas

    Earth-like Planets Aren’t Rare

    Renowned planetary scientist James Kasting on the odds of finding another Earth-like planet and the power of science fiction.

The Seed Salon

Video: conversations with leading scientists and thinkers on fundamental issues and ideas at the edge of science and culture.

Are We Beyond the Two Cultures?

Video: Seed revisits the questions C.P. Snow raised about science and the humanities 50 years by asking six great thinkers, Where are we now?

Saved by Science

Audio slideshow: Justine Cooper's large-format photographs of the collections behind the walls of the American Museum of Natural History.

The Universe in 2009

In 2009, we are celebrating curiosity and creativity with a dynamic look at the very best ideas that give us reason for optimism.

Revolutionary Minds
The Interpreters

In this installment of Revolutionary Minds, five people who use the new tools of science to educate, illuminate, and engage.

The Seed Design Series

Leading scientists, designers, and architects on ideas like the personal genome, brain visualization, generative architecture, and collective design.

The Seed State of Science

Seed examines the radical changes within science itself by assessing the evolving role of scientists and the shifting dimensions of scientific practice.

A Place for Science

On the trail of the haunts, homes, and posts of knowledge, from the laboratory to the field.


Witness the science. Stunning photographic portfolios from the pages of Seed magazine.

SEEDMAGAZINE.COM by Seed Media Group. ©2005-2015 Seed Media Group LLC. All Rights Reserved.

Sites by Seed Media Group: Seed Media Group | ScienceBlogs | Research Blogging | SEEDMAGAZINE.COM