The Dam at Keppel Cove

My shorthand for something that carries certain but very modest upside set against vanishingly small but truly awful downside risk.

The remains of the broken dam under Helvellen in the lake district are remarkable: the whole top section remains but there is a massive hole in the dam where it burst.

I looked at it and thought: I would like to walk across: challenge my fear and just walk across its span. It’s been like that for almost 100 years, so it’s not going to collapse just because I walk it.

However, the downside risk is truly awful: I die, my children get to cry for the rest of their lives.

It’s not worth it. I did not do it.

I walked on back to my tent that day.

The people who built the dam were sure of their technology, the upside was certain. The downside was the risk of everyone in the village beneath being flooded out and / or killed.

For the unfortunate people of Glenridding this actually happened twice: both dams that were built failed over a 20 ish year period.

Guardian article