People collect water released through a sewage drain that feeds into the Guaire River, which carries most of the city's wastewater, in Caracas, Venezuela March 11, 2020
What they're collecting is storm water (runoff water) which picks up potential pollutants that may include sediment, nutrients (from lawn fertilizers), bacteria (from animal and human waste), pesticides (from lawn and garden chemicals), metals (from rooftops and roadways), and petroleum by-products (from leaking vehicles).
Pollution originating over a large land area without a single point of origin and generally carried by storm water is considered non-point pollution.