Pittsburgh Zoning Map - Floodplain Layer

By Carolyn Ristau

Introduction

Pittsburgh’s interactive zoning map includes many layers besides the zoning districts, most of which relate to requirements within or adjacent to the zoning code. For an overview on how to use the interactive zoning map, see our introductory post.

To select different layers, click the stack of paper in the upper right corner. The layers available are listed below. Today’s post features the Floodplain Areas layer, pictured above and in bold text below.

Zoning
- Zoning Districts
- Zoning Districts Outlines
- Zoning Max. Height Overlay
- Height Reduction Zone Overlay
- 1500’ Major Transit Buffer
- Parking Reduction Areas
- North Side Commercial Parking Prohibited Area
- Baum Centre Zoning Overlay
- Inclusionary Housing Overlay District
RCO (Registered Community Organization) Areas
City Divisions
- DPW Divisions
- Neighborhoods
- Council Districts 2012
- Council Districts 2022 (Current)
- Wards
Historic Preservation
- Mexican War Street Historic Boundary
- Individual City-Designated Properties
- Pittsburgh City Historic Districts
Environment
- RIV Riparian Buffer (125 Feet)
- Stormwater Riparian Buffer
- Floodplain Areas
- Landslide Prone
- Potential Steep Slopes Overlay Area
- Undermined Areas
Addresses
Allegheny County
City Boundaries
Imagery 2021

The Floodplain Layer

Overview

This layer of the interactive zoning map shows where in the city FEMA has identified areas that have a 1% chance of flooding during heavy rains in a given year. This was formerly referred to as the 100-year storm event, but this caused confusion as flooding in these areas happens more than once every 100 years. When these areas were originally identified, the 100-year storm may have been an accurate measurement. However, climate change has increased the frequency of these “100-year” events.

FEMA also maintains a searchable flood map on their website. Note: FEMA’s map may take a long time to load but it shows additional information, including areas with a 0.2% chance of flooding.

The areas that FEMA identified as having a 1% chance of flooding and that are mapped in Pittsburgh’s floodplain layer are also known as the Special Flood Hazard Area. Flood Insurance Rate Maps identify three levels within this area: A, AE, or AE Floodway.

To see whether a property in the floodplain is in the A, AE, or AE Floodway:

Click the portion of the parcel in question that is covered with the floodplain layer
Use the arrows to navigate between the pop-up windows as necessary

Relationship with Zoning

For property owners in the City of Pittsburgh to be eligible for flood insurance, the city must administer floodplain management regulations that meet state and federal requirements. These regulations are located in the Environmental Overlay Districts chapter of the Zoning Code (Chapter 906). The complete floodplain regulations cover several pages. The applicability and definitions of development and substantial improvement as they pertain to the floodplain areas are quoted below.

906.02.B Applicability
It shall be unlawful for any person, partnership, business or corporation to undertake, or cause to be undertaken, any construction or development anywhere within the floodplain unless zoning approval has been obtained from the Zoning Administrator and a permit has been issued by the Bureau of Building Inspection.
906.02.H.2 Improvements
(c) Any modification, alteration, reconstruction, or improvement of any kind to an existing structure to an extent or amount of fifty (50) percent or more of its market value, shall constitute a substantial improvement and shall be undertaken only in full compliance with the provisions of this section.
906.02.J.2 Specific Definitions
(f) Development means any man-made change to improved or unimproved real estate, including but not limited to the construction, reconstruction, renovation, repair, expansion, or alteration of buildings or other structures; the placement of manufactured homes; streets, and other paving; utilities; filling, grading and excavation; mining; dredging; drilling operations; storage of equipment or materials; and the subdivision of land.
(hh) Substantial improvement means any reconstruction, rehabilitation, addition, or other improvement of a structure, of which the cost equals or exceeds fifty (50) percent of the market value of the structure before the "start of construction" of the improvement. This term includes structures which have incurred "substantial damage" regardless of the actual repair work performed. The term does not, however, include any project for improvement of a structure to correct existing violations of state or local health, sanitary, or safety code specifications which have been identified by the local code enforcement official and which are the minimum necessary to assure safe living conditions.

It is important to note that the definition of “development” used for floodplain regulations covers more activities than the definition of “development” that applies to other requirements in the Zoning Code. The simplest way to look at this broader definition of “development” is that if you touch any part of a property that is within the floodplain area, even if you are not touching the portion in the floodplain, a floodplain application is required. In another departure from typical zoning regulations, the floodplain regulations also apply to “touching” the right-of-way in a floodplain area. For example, maintenance or repairs to a bridge where the abutments sit in the floodplain count as “touching” the right-of-way. A floodplain application reviewed by the zoning office is also required for those situations.

While anything in the floodplain that falls into this definition of development requires a floodplain application, typically only those activities that constitute a “substantial improvement” will require additional documentation to show compliance with the floodplain regulations.

For More Information

The city’s floodplain webpage includes an overview of what it means to be doing a project in the floodplain, definitions for frequently used terms in the floodplain process, and application materials for projects in the floodplain. More information about floods, floodplains, and flood insurance can be found on the websites for FEMA and the National Flood Insurance Program.

Challenges

As mentioned above, any project on a parcel in the floodplain, whether or not the work is in the floodplain, requires the submission of a floodplain application, as does any project in the floodplain in a right-of-way. Minor projects typically do not need to do more than file the basic paperwork, while projects with “substantial improvements” will have to submit documentation to show compliance with floodplain requirements. While the floodplain application can often be reviewed concurrently with other reviews on a project, it is possible for this to add time to the review process.

The requirement of a floodplain application is often a surprise for smaller projects or those that don’t typically have a zoning review requirement, which, again, can create delays while the paperwork is prepared and submitted for review.

Another challenge is that, since the definition of “substantial improvement” is based on the value of the building being improved, what constitutes a minor improvement on one property can be considered a “substantial improvement” on another.

Conclusion

Start with Pittsburgh’s interactive zoning map to check if your project is on a property partially or fully in the floodplain or is on a portion of the right-of-way in the floodplain. If your project meets either condition, check the floodplain requirements to see if the scope of work is considered a “substantial improvement” and prepare the appropriate paperwork prior to starting your permit application process. Include additional project cost if it is a “substantial improvement” and additional review time (more if it is a “substantial improvement”) in the project timeline.