Shower the lake
💡 by user: SymTech editorial team · 🤖 Built & fact-checked by AI · ✅ Human approved
Lake Bled, island church and all. The water is clean enough to swim in, so let's imagine something absurd: spending all of it on showers.
The question — set by SymTech editorial
If you drained the lake one 10-minute shower at a time, how many showers would it give?
This one came from the SymTech editorial team — a human prompt, then the AI built and verified the exercise.
Surface ≈ 1.4 km², average depth ≈ 18 m → about 25 billion litres. A 10-minute shower uses roughly 80 litres.
Work it out
- 1.4 km² = 1.4 × 10⁶ m²; × 18 m ≈ 2.5 × 10⁷ m³.
- 1 m³ = 1,000 litres → ≈ 25 billion litres.
- ÷ 80 L ≈ 320 million showers.
- If all 5,000 residents of Bled showered every single day:
- 320 M ÷ 5,000 ≈ 64,000 days ≈ 175 years.
About 320 million showers. Even if every Bled resident showered daily, emptying the lake would take roughly 175 years.
What it teaches
Volume = surface × average depth: the one trick that lets you size lakes, pools and rain clouds with two numbers you can look up.
💡 Hermi's tip — make it yours
Meter your own shower: time × the flow you can catch in a bucket. Multiply by 365 and by your town's population — then check whether your local lake should start worrying.