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Retention Pond Size Calculator
Size a stormwater retention pond for a development.
🌧️ Free Online Tool
⚡ Instant Results
📊 Clear Comparison
🔒 100% Free Tool
Volume
Compare Your Options And Get Clear Answers
Size a stormwater retention pond for a development.
Retention Pond Size Estimator
Enter your numbers below for an instant estimate.
0
💡 Tip: Volume = area x rainfall x runoff coefficient.
How It Works
Key concepts behind this calculator
1
Enter Values
Fill in each field with your own numbers.
2
Calculate
Results update as you change the inputs.
3
Review
Read the breakdown and the explanation.
4
Adjust
Change values to compare scenarios.
Quick Reference Guide
Retention Quick Guide
Typical values for reference.
| Impervious | Coefficient | Storage per ha | Note |
|---|---|---|---|
| 20% | 0.31 | ~155 m3 | Light |
| 50% | 0.55 | ~275 m3 | Mixed |
| 75% | 0.75 | ~375 m3 | Dense |
| 95% | 0.91 | ~455 m3 | Very dense |
| Rule of Thumb | Check inputs | Use as a guide | Round sensibly |
Common Questions
Retention Pond Size Calculator FAQ
Answers to common questions about this calculator.
Large enough to hold runoff from the design storm.
It gives a quick estimate of retention pond size from the values you enter.
No. It is a planning estimate, so check important figures with a professional or official source.
Yes. Edit any field and the result updates when you calculate.