unsluice
/ˈʌnsˌluːs/Definitions
1. verb
to release or allow a flow of water to escape from a sluice or other controlled passage
“The swollen river was unsluiced from the dam, causing widespread flooding.”
2. noun
the act or process of releasing water from a sluice or other controlled passage
“The unsluicing of the canal had a significant impact on the local ecosystem.”