Not exactly. I want to build Riverrun 2 here:

That’s a good bit west and north of Lord Harroway’s Town. This location would allow a castle to have rivers on three flanks and a moat on its western flank would give it the same capability to withstand sieges as Riverrun. 

Moreover, two drawbridges anchored on that center spit of land could allow land traffic to cross from the south bank of the Red Fork to the north bank, and then from the north bank of the Red Fork to the northern bank of the Green Fork, at the castle’s discretion. At the same time, lowering the drawbridges would allow the castle to intercept river traffic on all three forks of the Trident.