About: http://webisa.webdatacommons.org/354794492

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	wait maybe I am being dumb, but if you are adding water, does not the volume and water level both go up, i.e. both positive always? (until overflow or something, then constant?)
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com