Newboro Lock the Rideau Watershed Photo Gallery. Newboro Lock the Rideau Watershed is a new photo lightbox by Ernie Hunter.Newboro Lock 36 was a major undertaking as it involved a one and a quarter mile long channel, cut through hard rock, to connect Upper Rideau Lake and Newboro Lake thus connecting the Rideau and Cataraqui Rivers. The Royal Sappers and Miners dug through hard granite rock using only picks and black power. Newboro is the watershed on the Rideau. It is upstream from Ottawa to Newboro, and upstream from Kingston to Newboro with Upper Rideau Lake as the highest elevation on the Rideau. View more quality stock images from Ernie Hunter here. 