Maintaining Venice's Canals | Venice for Visitors (2024)

Venice >Special topics > Canal maintenance

ABOVE: Wooden walkways giveworkers access to foundations along a drained canal.(Venice's buildings sit on foundations of Istrian stone--a type of whitemarble--which are supported by wooden pilings driven down through the mud to alayer of firm, solid clay.)

ByDurant Imboden

Robert Benchley, the humoristwho wrote for The New Yorker, once arrived in Venice and sent a cable to hiseditor that said: "Streets full of water. Please advise."

That pretty much sums up the challenges facing the Venice public-works department. Inmost cities, repairing the streets is a straightforward process of tearing up the oldpavement, grading the surface, and covering a base of dirt, gravel, or crushed rock with afresh layer of concrete or asphalt. In Venice, however, the streets consist largely ofcanals--and before the streets can be repaired, somebody has to get rid of the water.

The first step in canal maintenance is to erect one or more cofferdams. Thesetemporary walls seal off the canal from adjacent waterways such as the Grand Canal or theVenetian Lagoon.

Once the cofferdams are in place, the work crew uses pumps to drain the canal. Thencomes the hard part: removing the thick, charcoal-grey layer of silt and sludge that mayhave accumulated over several decades.

At the dredging site, a canal worker uses a small dragline (i.e., a duty-cycle crane)to dig up the sludge and transfer it into a wheeled vehicle with a tilting hopper.

Eachtime the hopper fills up, the vehicle's driver backs along temporary rails until hereaches a barge. He tips the muck into the barge, then returns to the waiting dragline.This process is repeated hour after hour, day after day, until the canal is ready to beflooded and reopened. Shovels are also used when needed, to clean out whatever thedragline leaves behind.

Two factors make the job more complicated than it might appear at first glance:

• Ancient pilings. Venice's palaces, churches, and other buildings are supportedby thousands of wooden pilings that date back hundreds of years. As long as they'resubmerged, the pilings won't rot--but when they come in contact with the air,deterioration begins. This requires that exposed wooden pilings be protected during thecleaning of the canal.

• Public utilities. Today's Venice has water mains, electric power lines,fiber-optic cables, andother utilities, just like any other city. Work crews must be careful to secure exposedutility lines and avoid damaging them while cleaning out the canals.

In TheWorld of Venice, Jan Morris describes the stoical menwho clean Venice's canals:

"Far down in the gulley of the empty waterway, beneath the ornatedoorways and marble steps of the palaces, you may see the labourers toiling in thesludge....Their bodies, their clothes, their faces are all smeared with the stuff, and ifyou engage them in conversation their attitude is one of numbed but still mordantresignation."

As the saying goes, "It's a tough job, but someone's got to do it." That'sreason enough to drink a toast of thanks to the canal workers of Venice as you sipProseccoon your next gondola ride.

More photos:

These photos show maintainance work on the San Felice Canal inCannaregio, just north of the Strada Nova.

The project includes restoration of a bridge, pavement, and foundations inthe insula of San Felice, Lotto 1. (Venice's historic center is dividedinto 40 "insulae," or districts, for integrated public-works projects.)

The view above shows a cofferdam with pumps on top. The hoses in the drainedcanal were used to suck up water and discharge it on the other side of the dam(small photo).

A barge sits on the muddy bottom of the drained canal, with a small backhoebeing used to excavate muck and sewage sludge, lift pilings into place, etc.

Traditional wooden pilings are used to replace old pilings that havedeteriorated after exposure to air during the renovation project.