https://upload.wikimedia.org/wikipedia/commons/d/d1/Blaeu_1645_-_Cl...
In these days the Rhine split just below Emmerich (1645) at Schenken Schans and the Northern branch went on in its now abandoned riverbed with AERDT and HARWERT on its western shore.
It is my thought that the name <VAN HARTENVELT> &/or <VAN HAERDT derives from this part of the Rhine basin.
I hope to find more background on this.
If we look at modern maps the river bed is much changed. But 1645 is significant era as it stands in the age of emigration for Denys Isaacszen Van Hartenvelt and Balthazar de Haerdt , two of the emigrants who I am researching in the https://www.geni.com/projects/Surrender-of-New-Netherland-1665-Sign...