Aboard a ferry crossing the IJ, to the east you may notice the KNSM island built and developed over the past few decades and featuring feats of contemporary Dutch architecture. The IJ extends further east towards the new polders of Flevoland, while to the west, via the North Sea Canal, nowadays the IJ extends all the way to the coastal town of Ijmuiden and empties into the North Sea.
First, in order to improve the connection between the Amsterdam IJ harbor and the North Sea, the North Holland Canal was built in 1824. However, the long and narrow canal was quickly deemed inadequate in handling the growing ship and boat traffic. Thus, a few decades later, it was decided to excavate a new canal along the narrowest point in the province of North Holland (of which Amsterdam is the capital) and, in this way, connect the Dutch capital to the North Sea by the shortest possible route.
Excavating began on 8 March 1865 in the dunes at Breesaap and lasted until the end of 19th century. Actually, no Dutch contractor was willing to take on this task, so the project was awarded to an English company.
The North Sea Canal was built by extending the IJ bay and lining it with dikes, after which the remaining portions of the bay were reclaimed and turned into polders. Thereafter, from the bay to the sea, a new canal was dug through the dunes in Velsen. In order to accommodate drainage from as well as shipping on such tributaries of the IJ as the Spaarne, the Zaan, and the Nauerna Canal, nine auxiliary canals needed to be dug as well (Side Canals “A” to “I”).
The canal was dug using mostly manual labor. According to sources, the workers lived in terrible conditions, being housed in huts built from twigs, driftwood, sod and straw, where disease, brawls and alcohol abuse were rampant. On November 1st 1876, the North Sea Canal was officially opened by King William 3 of the Netherlands. In the decades thereafter the canal has been widened, reinforced and deepened several times.
At the eastern end of the canal, past the KNSM island, the IJ bay used to open into the Zuiderzee until 1872 when the Orange Locks (Oranjesluizen) were constructed. Upon the completion of these locks, the North Sea Canal and the IJ Bay were not only no longer open to the open sea, but the water level of the IJ could henceforth be controlled.