Lagoon City is located on the east shore of Lake Simcoe and consists of residences fronting on a network of man-made canals. Since 2008, Tatham Engineering has been completing bi-annual detailed visual inspections of two wood-framed pedestrian suspension bridges which span the canals.

Further to the reviews and identification of deficiencies, Tatham Engineering prepared specifications to facilitate the immediate repair of the south bridge in 2009. A replacement structure was designed for the north bridge. To minimize future maintenance costs, the replacement A-frame towers, stringers and guard posts were constructed with structural steel as opposed to wood.

In 2016, Tatham Engineering was again retained to design a replacement structure for the south bridge. In keeping with the design of the north bridge, the replacement south bridge was designed with steel suspension system sub-structure, supporting an arched wooden deck.