Beresford St LittaTrap Trial


Beresford Street, Auckland




The Beresford Street Trial was a pilot study of the use of the LittaTrap™. A single catchpit insert was installed on the corner of Beresford Street and Hopetoun Street,
Auckland. The aim of the trial is to provide quantitative and qualitative data on the gross
pollutants captured by the LittaTrap™ in a typical inner city Auckland catchment.

The Beresford Street catchment is part of a steeply sloping street in Auckland’s Karangahape Road district. The catchment area is nominally ca. 300 m2 , however in periods of high flow it probably receives runoff from a substantially larger area, due to bypass of the uphill catchments on the steep slope.

The catchment has relatively low vehicle traffic loads but receives substantial
foot traffic. It is adjacent to several high-density apartment developments
and has both on-street and off-street car parking. The uphill end of Beresford
Street has several bars and cafes. It attracts substantial night-life and the
associated phenomenon of outdoor cigarette smoking.


The LittaTrap™ was first installed June 2012 and the content was emptied 3 times for
analysis purposes on March, April, and May 2013. In approximately 11 months of service,
the LittaTrap™ captured 10.72 kg (wet, drained weight) of gross pollutants.

Gross pollutants captured by the system were a mixture of predominantly negatively
buoyant road sediments, neutrally buoyant organic material and positively buoyant
trash and debris.

Most notably the number of cigarette butts found in 10.72 kg of debris
was estimated at 2000.

In addition, a considerable amount of debris, such as cans and
plastic and glass shards were found. These gain entry to the catchpit via the large kerb
entry slot, rather than the grate. Also found in the captured material were wrappers,
straws, wine corks and bottle caps.

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