Site 2: Culvert


Restoring a wetland involves much more than plantings. This seemingly natural landscape of ponds and streams has been created with the help of machines and man-made structures.

The weir controls the flow of water into Travis Stream. It is one of the series of flap gates on the streams bordering the swamp. These structures artificially maintain water levels in the wetland by slowing down outflows.

Tucked under the flax clump on the side of the weir is a giant ruler. This is the former Drainage Board datum point Christchurch. The datum was set up as a point at 9.043 m below sea level to measure land and water levels from. The levels you see on the gauge represent 9.7 m to 10.3 m above that point Travis water levels are typically between half and one meter above sea level.

The main pond was excavated on a site where the water table was naturally close to the surface. Low banks were built up to contain the water.

Culvert`

Culvert

Many of the north-south linear ditches that once drained this end of the swamp have been converted into more natural looking small ponds and damp depressions (known as swales).

Turn off the short side track to the bird hide and Site 3.

 

Can you find this plant ?

Grey Willow, Salix cinerea

Despite being a common plant of wetlands the Grey Willow is regarded as a pest plant.

Growing to 7m in height the Grey Willow spreads by  by seed or by suckering from the roots.

This plant replaces native species in wetlands, and forms vast dense stands and thickets. It causes blockages, flooding and structural changes in waterways.

At Travis Wetland the female plants have been removed and the males are being used as canopy plants to allow native species to establish themselves under them.

Grey Willow Male Catkin

Grey Willow Male Catkin

Grey Willow Female Catkin

Grey Willow Female Catkin

Can you see this bird ?

Grey Teal, Anas gracilis

The Grey Teal is a distinctive duck, it’s commonly likened to the shape of a toy duck, it also has a red eye.

The Grey Teal is a dabbling duck found in open wetlands, it breeds at Travis Wetland.

Grey Teal

Grey Teal

Grey Teal

Grey Teal