Tigard, OR Environmental Rules: Flood Zones (2026)
FEMA flood zone rules in Tigard, OR, also called floodplain regulations or special flood hazard area (SFHA) rules, determine flood insurance requirements and elevation standards for new construction.
Key Facts
- Permit required
- Before construction or development begins in a flood hazard area
- Map adopted
- FEMA Flood Insurance Study effective October 19, 2018
- Flood risk threshold
- One percent or greater chance of flooding in any year
- Substantial improvement
- Cost equals or exceeds 50% of market value
- Floodway encroachment
- Prohibited without engineer certification or CLOMR
- Violation class
- Class 1 civil infraction, each day separate
Summary
In the City of Tigard, Oregon, a development permit is required before construction or development begins inside any area of special flood hazard, and it covers all structures, manufactured dwellings, fill and other development. The areas are mapped by the Flood Insurance Study for Washington County effective October 19, 2018. Violations are Class 1 civil infractions.
I. Floodplain Development Permit Required. A development permit shall be obtained before construction or development begins within any area horizontally within the area of special flood hazard established in Section 9.10.030.B. The development permit shall be required for all structures, including manufactured dwellings, and for all other development, as defined in Section 9.10.020, including fill and other development activities. J. Application for Development Permit. Application for a development permit may be made on forms furnished by the Floodplain Administrator and may include, but not be limited to, plans in duplicate drawn to scale showing the nature, location, dimensions, and elevations of the area in question; existing or proposed structures, fill, storage of materials, drainage facilities; and the location of the foregoing.
Full Breakdown
Chapter 9.10 of the Tigard Municipal Code regulates development in the flood hazard areas of the City of Tigard, Washington County. Section 9.10.030 applies the chapter to all development within areas of special flood hazard, together with TCDC Chapter 18.510, Sensitive Lands, and adopts by reference the Flood Insurance Study for Washington County, Oregon and Incorporated Areas effective October 19, 2018, with its accompanying Flood Insurance Rate Map panels. An area of special flood hazard is land subject to a one percent or greater chance of flooding in any given year.
Section 9.10.040.I requires a floodplain development permit before construction or development begins. The permit applies to every structure, manufactured dwellings included, and to all other development as defined in § 9.10.020, which covers buildings, mining, dredging, filling, grading, paving, excavation, drilling and storage of equipment or materials. The Floodplain Administrator reviews each permit under § 9.10.040.C to confirm other local, state and federal permits are in place, whether the site is in a floodway, whether base flood elevation data exists, whether the work is a substantial improvement, a watercourse alteration, or involves fill or excavation. A substantial improvement is work costing 50% or more of the structure's market value.
The application under § 9.10.040.J includes plans drawn to scale showing nature, location, dimensions and elevations, the proposed lowest floor elevation in riverine zones, floodproofing certification by an Oregon licensed engineer or architect for nonresidential structures, a description of any watercourse alteration, a substantial improvement calculation, and the amount and location of any fill or excavation.
Floodways carry the tightest limit. Section 9.10.050.N prohibits encroachments, including fill, new construction and substantial improvements, in the adopted regulatory floodway unless a registered professional civil engineer certifies through hydrologic and hydraulic analyses that there will be no increase in flood levels, or a Conditional Letter of Map Revision is approved. Under § 9.10.050.H, new critical facilities must be located outside areas of special flood hazard to the extent practicable.
Violations & Fines
Section 9.10.060 makes any failure to comply with Chapter 9.10 a Class 1 civil infraction under Chapter 1.16. Each violation of a separate provision is a separate infraction, and each day a violation continues is a separate infraction. A finding of violation does not relieve the responsible party of the duty to abate it, and penalties are in addition to the city's other remedies. A structure or development lacking required elevation certificates or other compliance evidence is presumed to be in violation under the § 9.10.020 definition.
Frequently Asked Questions
Do I need a permit to build in a Tigard flood zone?
Which flood maps does Tigard use?
Can I fill or build in the regulatory floodway?
What is the penalty for building in a flood zone without a permit?
Sources & Official References
Other rules in Tigard
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Flood Zones in Nearby Cities
How other cities in Washington County handle flood zones.