Water in Amsterdam’s canals quite salty

DutchAmsterdam.nl — It’s not recommended, but if you were daring enough to take a few sips of water you’ll notice a marked difference: the water in the IJ — the river behind Amsterdam Central Station — is considerably saltier than the water in, say, the Leidsegracht, a canal in the center of Amsterdam.

That’s no surprise, really. Each time the locks at IJmuiden, a seaport city 21 kilometers west of Amsterdam, open seawater flows into the Noordzeekanaal (North Sea Channel).

The salty water mixes with the sweet water of the Amstel delta and the IJsselmeer (Lake IJssel), and the brackish water eventually reaches the canals of Amsterdam.

Maarten Ouboter of Waternet was aware of this fact, but he says, “We now know precisely where the brackish water is and how it spreads through Amsterdam’s canals and beyond.”

Waternet

Waternet is the Water Company in the area of Amsterdam and surroundings. It is the only water company in the Netherlands that is dedicated to the entire cycle: from waste-water management to the production of drinking water. It also maintains water levels and keep the surface water clean.

It does so on behalf of the regional Water Board Amstel, Gooi and Vecht. Earlier this year the Water Board tasked Waternet with a research project to determine the levels of salt and oxygen in the water of the canals and the Amstel and IJ rivers.

Speaking to local news daily Het Parool, Ouboter says the water in some parts of Amsterdam’s canals is so brackish that Waternet has found so-called Comb Jellies — typical sea creatures.

There is technical terminology to express the amount of salt in water, but to put it in layman’s terms: “In the IJ one liter of water contains about 5.000 milligrams of salt. Along the North Sea coast at Bloemendaal you can count on 17.000 milligrams per liter,” says Ouboter.

Oxygen is a good measure for the quality of water. The more oxygen, the better. The IJ and the larger canals in the east of Amsterdam contain the highest levels of oxygen; the water of the canals in the Jordaan district the lowest.

Among other things, the research results are used by Waternet to determine how best to refresh the water in the canals using the city’s various sluices.

Swimming in the canals of Amsterdam?

The ambition of Waternet is to someday have the canal water of Amsterdam clean enough for people to swim in, even though swimming in the busy canals may in reality not be tolerated due to safety concerns.

Incidentally, in 2009 Project ‘Schoonship’ (Clean Ship) was started: an effort to connect all of Amsterdam’s 3.000 houseboats to the sewer system. Target date for completion of the project is 2018.

Hence a word to the wise: don’t plan on swimming in the canals of Amsterdam any time soon, and don’t perform your own taste test either.