Renwick is a close satellite town of Blenheim at the junction of the road to St Arnaud (lake Rotitti) and Wairou Valley (and hotel)and the highway to Nelson. This is a busy junction and Renwick gains an economic spin-off from the traffic. Also, owing to high house prices in Blenheim an overflow to Renwick also exists.
Renwick is located in the centre of Marlborough's grape growing region. Sauvignon blanc is the variety usually associated with the area, and famous wineries such as Isabel Estate and Forrest Estate are in close proximity.