The Pikowai catchment is long and narrow beginning near Lake Rotoma and running north-east to the coast. The stream has a catchment area of approximately 30 km2 and winds its way through ignimbrite and volcanogenic sediments. There is exotic and native forest dominant in the upper catchment and pastoral land-use is dominant in the lower catchment with patches of exotic and native forest.
The stream is monitored at State Highway 2. No significant water quality trends are apparent.