Safety

PMP Calculator — probable maximum precipitation depth–duration–area

Probable maximum precipitation estimates for dam safety and extreme-event design, including HRU-style classification workflows.

What is PMP Calculator?

Probable maximum precipitation estimates for dam safety and extreme-event design, including HRU-style classification workflows.

When would you use this?

  • Dam safety studies that require PMP depth–duration–area inputs.
  • Extreme storm checks beyond standard IDF tables.

How Delta Hydro Studio handles it

  • Engineering-grade workflow tuned for professional dam-safety memos.
  • Outputs structured for pairing with PMF routing tools.

How to use it

  1. 1

    Define the site and storm duration range of interest.

  2. 2

    Select the appropriate PMP estimation pathway for your region.

  3. 3

    Review depth–duration–area results for consistency.

  4. 4

    Export tables for your hydrology appendix.

Methodology & references

Full equations, assumptions, and literature references appear inside the in-app methodology panels for this tool, aligned with South African guidance (SANRAL TRH, SANCOLD, DWS technical manuals) and international references (USDA NRCS, FHWA HDS) where applicable.

Outputs & exports

Export professional Word and Excel report packs, tabulated results, and GIS-friendly layers depending on the tool. Screenshots in marketing materials are refreshed as the UI evolves — the studio always reflects the latest layout.

Ready to run PMP Calculator?

Free tier available — no credit card required to explore.

FAQ

Do I need a desktop GIS install to use PMP Calculator? +
No. Delta Hydro Studio runs in the browser — upload inputs, run calculations, and export professional outputs without local GIS installs for most workflows.
Is there a free tier? +
You can start free on the Stream plan with credits to explore tools. Several hydraulic and delineation tools remain accessible without a paid subscription.
Where are my data and calculations stored? +
Projects live in your Delta Hydro Studio workspace. Export Word, Excel, and GIS formats when you need offline archives or submittals.

Related tools

Ship compliant studies faster

Create your workspace on the Stream plan, then open PMP Calculator when you are ready to run production calculations.