California
Detention and Retention Pond Design
Design of detention basins, retention ponds, underground storage and outlet structures to control runoff.
What the work involves
Detention basins temporarily store runoff and release it slowly; retention ponds hold a permanent pool. The engineer sizes storage, designs outlet structures and emergency spillways, checks soils for infiltration or liners, and provides maintenance guidance. Underground chambers are used where land is costly. Failing or silted ponds may need a redesign or retrofit.
Local conditions we plan for
- High seismic hazard and active faults
- Wildfire in the wildland urban interface
- Landslides and debris flows on steep slopes
- Coastal bluff erosion and sea level rise
Building code: California Building Standards Code (Title 24), based on the 2024 IBC and IRC, statewide (ICC adoption chart, April 2026).
When you need it
- Development requires peak flow control
- Limited space requiring underground detention
- Existing pond is silted, eroding or overflowing
- HOA or owner needs pond maintenance or retrofit plan
- Pond embankment shows seepage or slumping
Frequently asked questions
How much does detention and Retention Pond Design cost?
Across the US, detention and Retention Pond Design usually costs $5,000 to $50,000. Estimate. Underground systems and dam-safety-regulated embankments cost more.
How long does detention and Retention Pond Design take?
Plan on 3 to 10 weeks from signed proposal to stamped deliverables, longer if a site visit, soil testing or a permit review cycle is involved.
Do I need a licensed PE for detention and Retention Pond Design?
In most US jurisdictions, yes. When the work needs a permit, the plans, calculations or report usually must be sealed by a Professional Engineer licensed in the state where the project is located. Every deliverable we issue for permit is sealed that way.
How do I verify an engineer's license in California?
Engineers practicing in California are licensed by the Board for Professional Engineers, Land Surveyors, and Geologists (BPELSG). You can confirm a license number and its status in the board's public license search before you sign a contract.
Which building code applies in California?
California Building Standards Code (Title 24), based on the 2024 IBC and IRC, statewide (ICC adoption chart, April 2026). Cities and counties can add local amendments, which is one reason to hire an engineer who works in your area.
What site problems do engineers see most in California?
Common issues include high seismic hazard and active faults, wildfire in the wildland urban interface, landslides and debris flows on steep slopes and coastal bluff erosion and sea level rise.