Boterdiep

In the 15th century, the Cleisloot provided a connection to Bedum north of the city of Groningen.^[1] In 1625, the ditch was transformed into a canal^[2] which resulted in Zuidwolde being cut into two parts.^[3]: 167 In 1653, the Boterdiep was extended to Onderdendam^[4] In 1660, it was extended to Kantens, and reached Uithuizen in 1695 where it ended in a little harbour.^[2][5]

From the 17th century until the beginning of the 20th century, the Boterdiep was a main inland canal, and was aligned on either side by towpaths.^[4] The canal used to begin at the Turfsingel [nl] in the centre of Groningen.^[2] In the early 20th century, the Van Starkenborgh Canal was dug, and in 1912, the Boterdiep was re-routed to the new canal.^[3]: 98

The section in Groningen was filled up and was renamed Gedempte Boterdiep.^[3]: 98 In 1973, another 700 metres was filled up to allow for the construction of a road to Eemshaven.^[6] The canal did not agree and two months later, after heavy rain, had managed to return.^[7] The Boterdiep is nowadays mainly used for recreational boating and a 6 km/h speed limit applies.^[8] In 2020, the towpaths were reconstructed as a cycle and pedestrian tracks.^[9]