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Delaware County, PA Environmental Rules: Flood Zones (2026)

Some Restrictions

Compiled from the official code textEditor Martyn O'NeillLast verified August 2026

FEMA flood zone rules in Delaware County, PA, also called floodplain regulations or special flood hazard area (SFHA) rules, determine flood insurance requirements and elevation standards for new construction.

Key Facts

Governing ordinance: Ch. 62, Ord. No. 77-5 (1977)
Max elevation increase allowed: 1 foot (§62-10B)
Floodway residential ban: No dwellings in floodway (§62-10C)
Fill lateral extent: 15 ft beyond structure
Applies where: No municipal floodplain ordinance filed

FEMA Flood Zone Lookup

FEMA assigns every parcel in the U.S. a flood-hazard designation on its Flood Insurance Rate Maps (FIRMs). Zones starting with A or V are high-risk Special Flood Hazard Areas where federally backed mortgages require NFIP flood insurance. Zone X indicates moderate-to-minimal risk, where insurance is optional but often recommended. Your specific zone determines insurance cost, build elevation, and permit requirements in Delaware County, PA.

Zone	What it means	NFIP required?
A	High-risk flood area; 1% annual chance flood, no detailed analysis.	Yes
AE	High-risk; same as A but with established Base Flood Elevations.	Yes
AH	High-risk shallow flooding (1-3 ft), usually ponding.	Yes
AO	High-risk shallow flooding (1-3 ft) with sheet flow on sloping terrain.	Yes
V	High-risk coastal zone subject to wave action (no BFE).	Yes
VE	High-risk coastal zone with wave action and established BFEs.	Yes
X (shaded)	Moderate risk; between the 1% and 0.2% annual chance flood.	Recommended
X	Minimal risk; outside the 0.2% annual chance floodplain.	No

Look up Delaware County, PA on the FEMA flood map

FEMA maps update periodically; verify zone before buying flood insurance or building.

Summary

Delaware County's Floodplain Protection Ordinance, Chapter 62, blocks subdivision or land-development approval that would raise the one-hundred-year flood elevation more than one foot and bars new residential building sites inside any floodway. It steps in only where a Delco municipality has no floodplain-compliant subdivision ordinance of its own, filed with the County Planning Department.

These county ordinances apply to unincorporated areas of Delaware County. Incorporated cities within the county may have their own rules that take precedence over county-level regulations.

No subdivision and/or land development, or part thereof, shall be approved if the proposed development and/or improvements will, individually or collectively, increase the one-hundred-year flood elevation more than one foot at any point.
C. Building sites for residences or any other type of dwelling or accommodation shall not be permitted in any floodway area. Sites for these uses may be permitted outside the floodway area if the sites or dwelling units are elevated to the regulatory flood elevation. If fill is used to raise the elevation of a site, the fill area shall extend out laterally for a distance of at least 15 feet beyond the limits of the proposed structures and in compliance with § 62-10B certified by a registered engineer.
D. Building sites for structures or buildings other than for residential uses shall also not be permitted in any floodway area. Also, such sites for structures or buildings outside the floodway shall be protected as provided for in § 62-10C above. However, the Delaware County Planning Commission may allow the subdivision and/or development of areas or sites for commercial and industrial uses at an elevation below the regulatory flood elevation if the developer otherwise protects the area to that height or assures that the buildings or structures will be floodproofed at least up to that height.
E.

View official code

Full Breakdown

Chapter 62, adopted November 9, 1977 by Ord. No. 77-5 and effective November 20, 1977, regulates subdivision and land development inside any "designated floodplain district" shown on the federal Flood Insurance Studies for Delaware County municipalities. 3 of the National Flood Insurance Program regulations; once a municipality adopts and files a compliant ordinance with the County Planning Department, Chapter 62 drops out there. Section 62-10B forbids the county from approving any subdivision or land development that would, alone or together with other projects, raise the one-hundred-year flood elevation more than one foot at any point.

Section 62-10C bars residential building sites in a floodway outright; outside the floodway, a site may be used only if elevated to the regulatory flood elevation, and any fill placed to reach that height must extend at least 15 feet beyond the proposed structure, certified by a registered engineer. Section 62-10D applies the same floodway ban to commercial and industrial structures, though the County Planning Commission may allow development below the regulatory elevation if the developer floodproofs to that height. Preliminary and final plans, filed under §§62-8 and 62-9, must show the one-hundred-year flood boundaries, proposed lot lines, fill areas and protective facilities, prepared by a registered engineer or surveyor. Developers disturbing 25 or more acres also need a soil-and-erosion permit from the PA Department of Environmental Protection under §62-7C.

Violations & Fines

Chapter 62 has no standalone fine schedule; it works through the county's plan-approval gate. The Delaware County Planning Commission must find a preliminary or final plan compliant with §§62-8 through 62-11 before approving it, so a plat that raises the flood elevation more than a foot or places a dwelling in a floodway is simply rejected. Section 62-6 confirms that any approval creates no county liability for flood safety.

Frequently Asked Questions

Does the county floodplain rule apply inside Chester or Radnor?

Only if that municipality has no subdivision ordinance with its own floodplain provisions on file with the County Planning Department. Section 62-5 makes Chapter 62 a backstop: once a Delco municipality adopts and files a compliant floodplain ordinance meeting NFIP Section 1910.3, the county chapter no longer governs subdivisions there.

Can a floodway lot be filled and built on?

No for residences. Section 62-10C bars residential building sites in any floodway; outside the floodway, a site may be raised with fill only if it extends at least 15 feet beyond the structure and is certified by a registered engineer, and the site must still reach the regulatory flood elevation.

How much can a subdivision raise flood levels?

Section 62-10B caps it at one foot. The Delaware County Planning Commission cannot approve a subdivision or land development that would increase the one-hundred-year flood elevation by more than one foot at any point, whether from that project alone or combined with others already approved nearby.

Sources & Official References

[1]Delaware County, PA Code, Ch. 62 Floodplain Protection

Other rules in Delaware County

Parking Rules: Overnight ParkingSome Restrictions Animal Ordinances: Dog Leash LawsSome Restrictions Stormwater ManagementSome Restrictions Flood Elevation RequirementsSome Restrictions Erosion ControlSome Restrictions Parking Rules: Driveway RulesSome Restrictions Parking Rules: Loading ZonesSome Restrictions Parking Rules: Abandoned VehiclesSome Restrictions Animal Ordinances: Wildlife FeedingSome Restrictions

All Delaware County rules

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