https://www.openstreetmap.org/way/904467736 name is also suspicious, nothing on ground and nothing found on internet. 

The Main source is in fact inside https://www.openstreetmap.org/way/451904583 (need to be redraw it's smaller) Digitaal Hoogtemodel Vlaanderen II, Skyview factor 0,25 m show the outline and the spring si on the NW part.

For the records, theres also some suitements on the incline part of the park but it's marginal (it's more little wetland than a spring). 