flow rates. Geological evidence indicates that this mobility has extended to the river itself in the past, at times flowing through the current location of Christchurch into what is now the Avon Heathcote Estuary, and on a separate occasion flowing into Lake Ellesmere / Te Waihora, to the south of Banks Peninsula. To protect Christchurch and other settlements near the river, multiple flood protections have been constructed either side of the river since European settlement, dating as early as the Canterbury Rivers Act 1868. The river currently reaches the Pacific Ocean just to the north of Christchurch, entering Pegasus Bay by way of Brooklands Lagoon. The Waimakariri marks one of only a few breaks in the roughly length of Pegasus Bay. Along with two other rivers which enter Pegasus Bay (Ashley River / Rakahuri and Waipara River), the Waimakariri is almost entirely responsible for the sediment which forms the bay and its coastal plain. Bridges Due to the size of the river, only a limited number of bridges cross the Waimakariri. From upstream to downstream, the current bridges are: Waimakariri Falls This simple suspension bridge (a.k.a. as a three-wire bridge) is just downstream from the Waimakariri Falls located on a tramping track close to the Waimakariri Falls Hut. Bealey Bridge The Bealey Bridge is located immediately upstream from where the Bealey River flows into the Waimakariri. It is part of State Highway 73. Bealey Bridge is single-lane, with a passing bay in the middle. It is in a remote location and does not cater for pedestrians. Midland Line bridge #42 Some downstream from the Bealey Bridge, the Midland Line crosses the river. KiwiRail records this bridge as number 42 on its bridge asset list. It is located where Red Beech Stream flows into the Waimakariri. Mount White Bridge The Mount White Bridge is, as the crow flies, located downstream from the KiwiRail bridge. It is much older than the Bealey Bridge. The abutment on the left bank of the Waimakariri is located within the delta created by the Hawdon River. Waimakariri Gorge Bridge The Waimakariri Gorge Bridge is, as the crow flies, located downstream from the Mount White bridge. This bridge was completed in 1877 and originally served both road and rail traffic (of the Oxford Branch). The bridge is on the register of Heritage New Zealand as a Category II structure. SH1 Waimakariri Bridges The SH1 Waimakariri Bridges are