Professional services
PMF Analysis (Probable Maximum Flood) in South Africa
PMF hydrology for high-consequence dams & structures. Storm maximisation, routing & documentation — Delta Hydro Engineers.
Request a QuoteWhat is PMF analysis?
PMF analysis estimates the probable maximum flood for high-consequence facilities—combining storm maximisation and catchment routing to support dam safety and risk governance.
Extreme floods with audit trails
PMF work is judged on whether another specialist can re-derive your critical duration and inflow from the appendix. We document transposition, losses, and routing decisions so the safety case narrative and the numbers tell the same story.
Panel-ready responses
We anticipate typical review questions—routing stability, spillway split flows, sensitivity to initial reservoir level—and address them up front to shorten review cycles.
What we typically need from you
- Dam classification, consequence category, and applicable guideline references
- Catchment characteristics, reservoir rule curves, and spillway geometry datasets
- Prior PMF/PMG studies or independent review comments to address
- Meteorological product preferences or transposition constraints from the safety panel
Where we add technical depth
- Storm maximisation and duration logic documented for critical duration selection
- Catchment routing consistent with reservoir storage, spillway performance, and gates
- Sensitivity matrix for contested assumptions (snowmelt, losses, transposition)
- Appendix structure suited to dam safety reviewers and legal disclosure if required
When do you need this?
- High-consequence dams where extreme flood estimates govern safety
- Regulatory or insurer requests for PMF demonstration
- Comparing PMF vs PMP/PMF scenarios for sensitivity
Our approach
- 1
Standard selection
Agree the hydrometeorological standard and documentation expectations for the safety case.
- 2
Storm maximisation
Construct critical duration storms and transposition logic where applicable.
- 3
Catchment routing
Route losses and hydrographs consistently with reservoir and spillway modelling.
- 4
Reporting
Deliver a peer-reviewable memorandum with appendices and sensitivity tests.
What you'll receive
- PMF hydrology memorandum
- Hydrographs and key tables
- Sensitivity documentation
Relevant SA standards
- SANCOLD guidelines for extreme floods
- DWS dam safety regulatory context
Case study
Ask us for anonymised examples relevant to your sector.
FAQ
PMF vs design flood?
PMF is an extreme scenario; design floods may differ by application. We align to the dam safety brief.
Do you include climate change?
Where the brief requires, we can discuss sensitivity approaches—documented explicitly.
Independent review?
We prepare packs for reviewers and respond to technical queries.
Storm transposition?
Where applicable, we document transposition logic and critical duration selection.
Reservoir routing?
Routing is integrated with spillway performance and storage constraints in the safety case.
Author
Robert FortuinAreas we serve
We prepare location-specific briefs for major centres across South Africa — see locations.
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