Intensive research field work shows that its beach water quality is strongly influenced by the flow and pollution from its local stream. The stream flows through the Tai Long Wan Village, which can carry non-point source pollutants washed off from the hinterland during rain events. Its water quality in rainy season is significantly worse than in dry season. Salinity and rainfall are good predictors of beach water quality at this beach, as it indicates the amount of potentially polluted fresh water from the stream.

Monthly distribution of beach gradings at Big Wave Bay beach (2010-2014)

Aerial photo and local pollution sources
Source 1: Stream
A stream discharges into beach water	The response of the streamflow to precipitation
The streamflow is predicted by the hydrological model, the MIKE-SHE model. Click here to know how the simulation is carried out.