Miami-Dade vs. Broward County Drainage Design Standards: Key Differences for Developers

South Florida’s flat terrain and frequent heavy rains make drainage design one of the most important elements of site development. However, not all counties follow the same rules. Developers working across Miami-Dade and Broward County often discover that stormwater management requirements differ in critical ways—affecting everything from permitting timelines to construction costs.

In this guide, RSP Engineers compares the two counties’ drainage design standards and explains how civil engineers help projects meet compliance.

Why Drainage Standards Differ

While both counties are governed by Florida Department of Environmental Protection (FDEP) and South Florida Water Management District (SFWMD) regulations, local ordinances add unique requirements. Each county tailors its standards based on topography, flood risk, and existing stormwater infrastructure.

Miami-Dade vs. Broward Drainage Requirements

Requirement	Miami-Dade County	Broward County
Reviewing Authority	DERM (Division of Environmental Resources Management)	EPGMD (Environmental Protection & Growth Management Department)
Design Storm	25-year, 72-hour storm minimum	100-year, 3-day storm for critical facilities
Retention vs. Detention	Encourages on-site retention with groundwater recharge	Focuses on detention and controlled discharge
Water Quality	Strict pollutant loading calculations required	Requires treatment for first 1 inch of runoff
Approval Timeline	Often lengthy due to multiple agency reviews	Streamlined but requires extensive documentation

Developer Takeaways

• Miami-Dade emphasizes water quality protection and retention, making it especially strict on projects near sensitive ecosystems.

• Broward County focuses on flood risk management, with more rigorous requirements for detention and critical infrastructure.

• Working across both counties often requires dual expertise in drainage modeling, permitting strategy, and regulatory coordination.

Common Mistakes in Drainage Submittals

1. Using the wrong design storm for the county.

2. Submitting incomplete pollutant loading or runoff calculations.

3. Failing to coordinate with both municipal and county reviewers.

4. Not accounting for FEMA floodplain impacts in design.

Conclusion

For developers, understanding the distinctions between Miami-Dade and Broward drainage standards is essential to avoid delays and costly redesigns. Partnering with a licensed Florida drainage engineer ensures compliance, accurate hydraulic design, and smoother approvals.

FAQs

• Do both counties follow SFWMD regulations?

  Yes, but each adds its own local requirements. See SFWMD stormwater rules for regional standards.

• Which county is stricter on water quality?

  Miami-Dade, due to its emphasis on aquifer recharge and pollutant loading.

• Do I need separate permits for city and county review?

  In most cases, yes. Your drainage engineer should coordinate with both.

• Can I use the same stormwater model for both counties?

  Not always. Different design storms and review thresholds apply.

• How do RSP Engineers help with county approvals?

  We prepare sealed drainage plans, run hydraulic models, and coordinate with both DERM and EPGMD to keep projects on track.

Work with Drainage Engineers Who Know Both Counties

At RSP Engineers, we’ve guided projects through the unique drainage requirements of both Miami-Dade and Broward County. From early modeling to final submittal, our team ensures designs meet every code, reducing risk of delays.

Planning a project in South Florida? Contact RSP Engineers today for drainage expertise across county lines.