Access issue water under the bridge

A temporary gravel causeway across the Te Roto O Wairewa (Lake Forsyth) outlet canal has been replaced with a modern bridge.

The bridge connects Birdlings Flat with Bossu Road and means there is now 4WD vehicle access across the beach for local residents and visitors, regardless of whether or not the lake is open to the sea.

It was blessed last week by Bishop Richard Wallace, the Bishop of the Anglican Maori Diocese O Te Waipounamu, ahead of being opened to 4WD traffic.

Bishop Richard Wallace, the Bishop of the Anglican Maori Diocese O Te Waipounamu, blesses the new bridge.

The new bridge has been built by the Wairewa Rūnanga, with the help of a $200,000 grant from the Lake Opening Endowment Fund administered by Christchurch City Council. It is one of the outcomes of a Memorandum of Understanding (MoU) signed by the Council and the Rūnanga last year.

The MoU committed the Council and the Rūnanga to working together to improve the health of Te Roto O Wairewa (Lake Forsyth).  

The lake has been affected by toxic algal blooms since the early 1900s, however, since the Rūnanga built a canal to open the lake to the sea, its health has improved.

The lake is opened to the sea when rain raises the risk of flooding. The water level needs to be lowered in a controlled manner, as if it drops too low, particularly in the spring or summer, the risk of toxic algae blooms rises.

A joint resource consent granted by Environment Canterbury allows the Council and the Rūnanga to manage the lake openings.

Construction of a bridge over the canal was one of the requirements of that consent.

Up until now a temporary gravel causeway has been used to link Birdlings Flat to Bossu Road, but the causeway has had to be removed each time the lake is opened.

This has meant that access across the beach has been restricted – sometimes for weeks – until the lake opening to the sea has been completed and the causeway replaced.