On a hot summer’s day, the cool waters of the local reservoir may seem placid and inviting. So much so, that every year, people across Wales venture into the water for a swim to cool off. This casual decision can prove fatal.

Swimming in reservoirs is dangerous. Even on the warmest day, freezing temperatures, deadly currents and hidden machinery can drag the strongest swimmer under. In fact, during a warm period in July 2013, 13 people drowned in UK waters, including two people in Welsh reservoirs over one weekend.

Despite prominent warning signs and regular news stories reporting tragic drownings together with the presence of rangers, each year Welsh Water employees have to deal – often in the face of hostility – with hundreds of people swimming in one of their 91 reservoirs.

Our creative campaign concept aimed to highlight the dangers hidden below the water, with the headline ‘beautiful but deadly’. The social campaign films started above the water on a hot sunny calm day at the reservoir, then flipped the footage 360° to go from a nice sunny day above the water to a dark and dangerous world below.