Orange County, FL Stormwater Regulations

Orange County holds a Phase I NPDES MS4 permit from FDEP (FLS000011), and the City of Orlando holds its own. Environmental Resource Permits come from two different water management districts: SJRWMD in the north, center and east, and SFWMD in the south-central and southwest. The county has no stormwater fee in effect, and county civil penalties reach $5,000 per offense per day.

Primary source: Orange County Code, Chapter 15, Article IV (Water Quality Management Ordinance)

Permit Requirements

Most projects in Orange County need an Environmental Resource Permit (ERP) for the stormwater system, and which agency issues it depends on location. The county is split between two water management districts. The St. Johns River Water Management District covers the northern, central and eastern parts of the county. The South Florida Water Management District covers a band across the south-central and southwest, handled from its Orlando Service Center. FDEP lists Orange as a partial county under both districts. The boundary follows a legal description in state law rather than city limits, so check your parcel with the district before you design.

Construction that disturbs one acre or more, or is part of a larger common plan of that size, also needs coverage under FDEP's NPDES Construction Generic Permit. File the Notice of Intent at least two days before work starts and keep a Stormwater Pollution Prevention Plan on site. For ERP applications deemed complete after December 28, 2025, SB 7040 requires 80% TSS, 80% total phosphorus and 55% total nitrogen reduction for standard projects.

In unincorporated Orange County, the county adds its own design standards through the subdivision regulations and the site development ordinance. Every development must treat one-half inch of runoff, or the runoff from the first inch of rain, whichever is greater. Post-development peak discharge can't exceed the pre-development peak for the 25-year, 24-hour storm. Sites with no positive outfall must hold the full 100-year, 24-hour storm and drain it within 14 days, and drainwells don't count as an outfall.

Inspection Obligations

Active construction sites follow the NPDES Construction Generic Permit schedule: a qualified inspector at least once every 7 calendar days and within 24 hours after a storm of 0.50 inches or more. Orange County's ordinance findings state that, as an MS4 permit holder, the county is responsible for inspecting private and public construction projects, commercial and industrial facilities, and stormwater ponds.

For permanent ponds and BMPs, the county code sets a duty to maintain rather than a fixed inspection interval. It is unlawful for anyone with operation or maintenance responsibility for a permitted stormwater facility to fail to keep it working to its permitted design. The county's Environmental Protection Division recommends owners inspect monthly, clear inflow and outflow structures, repair eroded slopes, and remove floating debris and pond sediment.

Industrial and commercial facilities and construction sites must report an accidental illicit discharge to the Environmental Protection Division within 24 hours of discovering it. The ERP operating permit from SJRWMD or SFWMD may also set inspection and certification conditions for your system, so read it alongside the county rules.

Penalty Structure

Orange County enforces its water quality rules through the Environmental Protection Officer. The officer can issue a notice to correct or a citation, and with Board of County Commissioners approval can order a facility to stop operating until the violation is fixed. In court, the county can recover a civil penalty of up to $5,000 per offense, and each day counts as a separate offense. The violator is also liable for damages to the county's waters and property and for the county's costs, including attorney's fees.

Cases can also go to the Code Enforcement Board or a special magistrate. Fines there run up to $1,000 per day for a first violation and up to $5,000 per day for a repeat violation, plus enforcement and repair costs. If the violation is irreparable or irreversible, the fine can reach $15,000 per violation. Recorded fine orders become liens on the property.

State enforcement under Chapters 373 and 403 of the Florida Statutes applies on top of county penalties. FDEP handles NPDES violations, and SJRWMD or SFWMD handles ERP violations such as building or changing a stormwater system without a permit.

Key BMPs

The county's subdivision and site development standards spell out how the main BMPs must be built:

• Dry retention and detention with filtration - Needs at least two feet of filter media and a locked backup bleed-down gate or valve. The pond bottom must sit at least three feet above the wet-season water table, or underdrains are required.
• Wet bottom ponds - Allowed with at least six feet of water below the control level and a length to width ratio no greater than two to one. In the Econlockhatchee basin, wet detention is required where soils won't support dry retention.
• Detention outlet structures - Must skim floating debris, oil and grease, and must release attenuation volume through a positive, non-filtering structure. Half of that volume must drain within 24 hours.
• Recharge retention - On Type A soils the county engineer can require retention of the full 25-year, 24-hour runoff. In SJRWMD's Wekiva Recharge Protection Basin, three inches of runoff from impervious areas on Type A soils must be retained and soak in within 72 hours.
• Exfiltration systems - Permitted for site development if a geotechnical engineer designs the system, inspects it full time during installation, and certifies it before occupancy.

Local Ordinances

The county's Water Quality Management Ordinance (Chapter 15, Article IV) bans illicit discharges and connections to the county storm system and requires owners to maintain permitted stormwater facilities. It applies countywide except in cities that have adopted standards at least as strict.

Two river protection ordinances add rules in sensitive basins. The Wekiva River Protection article bars development within 550 feet of the river and its wetlands, with narrow exceptions. The Econlockhatchee River Protection article limits peak discharge for the mean annual and 25-year storms and requires upland buffers averaging 50 feet around Class I and II conservation areas. SJRWMD basin rules add their own criteria in the Wekiva, Econlockhatchee and Lake Apopka basins. Orange County is also a named stakeholder in five FDEP Basin Management Action Plans: Wekiva River, Wekiwa and Rock Springs, Upper Ocklawaha, Lake Jesup, and Lake Okeechobee.

The Fertilizer Management Ordinance bans nitrogen and phosphorus fertilizer on lawns and planted areas from June 1 through September 30, keeps fertilizer 25 feet away from surface waters, and prohibits blowing fertilizer or grass clippings into storm drains and ponds. HOAs and lawn contractors working around ponds should build this into their schedules.

A stormwater utility has been on the books since 1996, with assessments based on impervious area, but the county rate has stayed at $0.00. Commissioners paused a study of activating the fee on June 30, 2026 and plan to revisit it in early 2027. Cities such as Orlando, Maitland, Ocoee, Winter Garden and Winter Park charge their own stormwater fees, so check the city if your property is incorporated.