As early as 1571
Duke Adolf I of Holstein-Gottorp proposed to build an artificial waterway across Schleswig-Holstein by connecting an eastward bend of the
River Eider to the Baltic Sea, so as to compete with the nearby
Stecknitz Canal for merchant traffic. At the time the
Duke of Holstein-Gottorp was a vassal of the
Kingdom of Denmark, but the dukes of Schleswig-Holstein were perennial enemies to their Danish suzerains, and the political fragmentation of the region and the ongoing conflict over its rightful rule posed an insurmountable obstacle to such a large project. The prospect of a canal was again raised in the 1600s under
King Christian IV and
Duke Frederick III. After the incorporation of Holstein into the Danish crown by the 1773
Treaty of Tsarskoye Selo, geopolitical conditions at last permitted a canal's construction and operation. Surveying and planning for the canal began in 1773, with a preliminary plan for the canal proposed in February 1774. On 14 April 1774, King
Christian VII of Denmark issued a cabinet order establishing a Canal Commission to oversee the construction, led by
Heinrich Carl von Schimmelmann.
Construction Preparations for the canal began in 1776 with
dredging of the lower Eider between
Friedrichstadt and
Rendsburg. The artificial canal was then excavated and fitted with
locks to allow ships to cross the peninsula's
drainage divide and descend to the
Kieler Förde on the Baltic coast. Construction on the artificial segment, eventually long, began in July 1777 at
Holtenau on the Baltic shore north of
Kiel, proceeding to Knoop by the following autumn. This section partly followed the small river
Levensau that emptied into the Kieler Förde. The section from Knoop to Rathmannsdorf was built between 1778 and 1779, and the highest segment (connecting to the
Flemhuder See) was completed in 1780. Finally, locks were installed along the upper Eider's natural course, starting at Rendsburg, to raise and deepen the river and make its upper reaches navigable as far as the western end of the artificial canal.
Replacement by Kiel Canal The Eider Canal soon carried a considerable volume of shipping, and as decades passed the growing number and size of the ships wanting to make the crossing strained the canal's capacity. The winding course of the Eider and the need to navigate through the
Frisian Islands at the canal's west end added to the travel time, and the
drafts of late-nineteenth-century
warships precluded their using the canal. In 1866 the
Second Schleswig War resulted in Schleswig-Holstein's becoming part of
Prussia, after which the German government explored a number of options for renovating or replacing the canal to improve commercial and military access to the Baltic. In 1887
Kaiser Wilhelm I inaugurated construction on a new canal through Schleswig-Holstein called the
Kiel Canal. Though the new canal's western end is farther south (at the mouth of the
Elbe), much of the Eider Canal's watercourse was reused for the new waterway. Many sections were deepened, and some were straightened, cutting off bends that still exist as
oxbow lakes. The new canal was opened by
Kaiser Wilhelm II in 1895. ==Packing houses==