"Coupure" in the dike under the Bovenkerkerweg in Amstelveen, the Netherlands. A coupure is an intentional opening in a dike, generally to facilitate traffic, that can be closed in an emergency. The dike under this road is a "slaperdijk" (litt. sleeping dike): a reserve dike to contain flooding in case the first dike (in the case, the dike of the river Amstel) should fail. This coupure was made on the occasion of the extension of lightrail line 51 from station Poortwachter to station Westwijk in Amstelveen. Steel flaps are normally held in a horizontal position enabling the passage of trains, cyclists and pedestrians, but can be lowered, closing the opening. Picture used on <a href="https://nl.wikipedia.org/wiki/Coupure_(waterbouwkunde)" class="extiw" title="nl:Coupure (waterbouwkunde)">nl:Coupure (waterbouwkunde)</a>.
<a href="//commons.wikimedia.org/wiki/User:MartinD" title="User:MartinD">MartinD</a>
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<span class="int-own-work" lang="en">Own work</span>