The Helwerdermaar and the vanished bridge, with characteristic opening in the concrete for unloading the harvest in a pram. - Photo: GW de Jager

The Boterdiep is connected to the South of Uithuizen by the Helwerdermaar with the Usquerdermaar. The part east of the Langenhuistil is also called Old Maar mentioned.

The channel has a natural origin and is navigable, albeit with difficulty, due to its shallow depth. The following bridges lie across the canal, with the flow from east to west:

  1. de Kleitil in the Havenweg (Uithuizen) / Trekweg (Dead still)
  2. the Oude Til (sometimes: Oudetil) in the Anyway
  3. the Langenhuistil (private), near the Langenhuis farm
  4. the Helwerdertil in the Usquerderweg (Rottum)
  5. the bicycle bridge next to the Helwerdertil

Until 2015, there was a pumping station with associated lock at the mouth of the canal, intended to compensate for the consequences of the subsidence due to gas extraction. After the construction of the Usquert pumping station in the Usquerdermaar, some 600 meters to the west, this was demolished.

The Meedstermaar and the Helwerdermaar once formed one watercourse. Due to the construction of the Boterdiep, this only lost its meaning.

Source: Excerpt from printed map, in four sheets, by Th. Beckeringh, 1781

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