I took these pictures at Ladybower Reservoir in the Upper Derwent Valley in Derbyshire. The reservoir has two spillway overflows at the side of the dam that look like plugholes. The plugholes regulate water levels in the reservoir by draining away excess water to the River Derwent when the reservoir level gets too high. The plugholes are big (24 metres in diameter, with a drop of 20 metres) and, when they overflow, are a sight to behold.

I knew the water level would be high after Storm Babet so I arrived at sunrise. The weather forecast was for clear skies but there was considerable mist. I hadn't planned for those conditions but the mist certainly added some atmosphere to the photographs.

This plughole is at the west end of the dam. I found it a tricky composition because there aren’t many places you can stand and retain its symmetry. This is as close as you can get, because there’s a wall in the way. If you move back, the reservoir wall gets in the bottom of the picture.

This plughole is at the east end of the dam. With the mist that I had on the day, I think this gives a more pleasing composition. There’s nothing you can do to avoid the railings in the bottom of the picture (short of flying a drone — more of that later).

Walking along the reservoir revealed these photogenic boats. I thought this composition worked well in the mist. The bridge in the background is the Ashopton Viaduct (the A57, Snake Pass).

This image shows a similar composition with less mist and a single boat. The hill you can see in the background is Crook Hill.

This is taken from Crook Hill looking back towards Ashopton Viaduct. It’s a classic view from this location but I was hoping the mist would give me something extra.

This was taken from the Ashopton Viaduct looking north towards Derwent Reservoir.

To really capture the plughole in context, I decided to fly my drone. It was too misty when I first arrived but later I was able to get this graphic shot of the plughole along with some autumn colour in the trees. This is the same plughole as in the first photograph above.

I know that drones aren't to everyone's taste, so I only fly when a place is empty or nearly empty of people. What I like about this view is that it makes you stop and question what you're seeing for a few seconds before you manage to put the pieces together. This is the plughole at the east end of the dam.