Spaarndam has five waste and locks. The Kolksluis (IJdijk approx.), Located on the site of the oldest lock from 1285, is still the oldest lock, but this has been out of service since 1927. Two possibly 18th-century stones have been inscribed and the coat of arms of the water board Rijnland.
To the east of this is the Woerdersluis (IJdijk approx.), The sluice of the Groot Waterschap van Woerden. This sluice from 1611 still has the old hard stone cladding. Further east is the Grote Sluis (Spaarndammerdijk approx.), A lock that was renovated in 1898 from 1567. The two most westerly locks are the Boezemsluis (Visserseinde approx.), A sluice from 1843 at the end of the Boezemkanaal, and the Kleine or Haarlemmersluis (Haarlemmersluizen approx.). This lock back to 1519 was renewed in 1806 and filled in around 1900, while maintaining a chamber on the south side.
