Dunes at Lyall Bay beach. Photo: James Grigg, Lyall Bay Coastcare
The importance of healthy dunes has been highlighted in recent months with the battering our coastline received from unusually large swells. While areas with rocky seawalls, like the eastern end of Lyall Bay, were badly damaged and will need major restoration work, the dune-protected main beach will gradually rebuild itself with a bit of help and protection from heavy foot traffic.
Restoration projects – both community-driven and those organised by the Council – can restore dunes, which are naturally adapted “shock absorbers”, by planting native sand binders like pīngao and spinifex. These plants trap sand with their leaves and hold it together with their roots.
Planting along stream margins is an effective way to reduce the impact of storms on our waterways. Restoring riparian (streamside) areas also provides habitat for fish, increases bird and insect life, lowers water temperature, reduces sediment, and filters out some pollutants.
Flooding is another result of more frequent storms, made worse in urban areas by the increase of hard surfaces – like roads and roofs – that quickly flush stormwater into increasingly overloaded drains. Wetlands are nature’s solution, as they store water during heavy rainfall and release it slowly afterwards. They also absorb nutrients and heavy metals, which means the water downstream is cleaner, and store more carbon than forests.
The Council uses water-sensitive urban design approaches to lower the risk of flooding in built-up areas. This also brings more native plants and animals into urban areas, and makes them more attractive. A few of our water-sensitive urban design projects include the tree pits in lower Cuba Street, 80 rain gardens along the quays, and the wetland in Waitangi Park.
Protecting and enhancing our aquatic ecosystems is one of the goals of our biodiversity strategy and action plan, Our Natural Capital. You can also make a difference to the health of your local beach, stream or wetland. To find an ecological restoration group near you, visit naturespace.org.nz