Our Capital Beaches - Effects of Stormwater Discharges

Stormwater Conference

Wellington's public stormwater system has 550 km of piped systems and approximately 25km of open semi-urban watercourses. The current stormwater network is a complex gravity system of reticulated pipes, culverts, catch-pits, grit traps, secondary overland flow paths and streams; which convey almost 80 million cubic meters of stormwater every year from buildings, roads, open spaces and other land uses into the city’s coastal receiving waters.

Stormwater transports sediment, debris, litter, biological matter and traces of other contaminants such as hydrocarbons and heavy metals. At the input end, these stormwater services clean the catchment environment, but do so by depositing the pollutants in the receiving environments. This means that the stormwater discharges affect the ecological, cultural, recreational and amenity values of the shared receiving environments.

Detailed catchment studies reveal that some of Wellington’s most intensive land uses and traffic flows, that generate more runoff and more contaminants, drain into areas where amenity and recreational values are also the highest - Lambton Harbour/Oriental Bay, Evans Bay, Lyall Bay and Houghton Bay.

This paper discusses: types, sources and loads of sediment and key physical and chemical contaminants in stormwater; and receiving environment status, impacts and recreational grading.

Conference Papers Resource - Conference Papers Stormwater

1. Rajika Jayaratne.pdf

pdf
668 KB
22 Jun 2016