The main zone types
- Zones that start with A or V: the Special Flood Hazard Area, with a 1 percent chance of flooding in any year. This is often called the 100-year flood zone.
- Shaded Zone X: moderate risk, often called the 500-year zone.
- Unshaded Zone X: minimal mapped risk.
- Zone D: risk not determined.
Why it matters for a site
Building in a Special Flood Hazard Area brings extra permits, design rules and insurance costs, and many projects avoid it. Land in a flood zone is usually taken out of the buildable acreage of a site.
How Voltane handles flood data
Voltane uses the FEMA National Flood Hazard Layer for Texas. Some counties have no digital FEMA map. Where a site is not fully covered by an effective digital map, Voltane shows flood exposure as unknown, never as 0 percent. A flood map is a screen. It does not replace a site-level flood study.
Questions people ask
Does outside the flood zone mean a site will not flood?
No. FEMA maps show modelled risk for certain flood sizes and can be out of date. Land outside a mapped zone can still flood.
Where can I check the official flood map?
Use the FEMA Flood Map Service Center. It is the primary source and shows the effective map for an address.
Related
More glossary
- What is time to power?
- What is powered land?
- What is a powered shell?
- What is large load interconnection?
- What is a point of interconnection?
- What is an interconnection queue?
- What is queue position?
- What is ERCOT?
Need a site, or have one?
Tell us what you need and Voltane finds, reports on and prices candidate sites in ERCOT. Or bring a site you already have for a path-to-power report (by request for now).