Flood Hazard Studies
Defining flood risk where the maps fall short
FEMA mapping doesn't cover every stream or show every property at the level of detail a decision may require. Colman Engineering performs flood hazard studies for clients across Virginia to define flood risk where mapping is missing, outdated, or too coarse. These studies provide a clearer, site-specific picture of the flood risk affecting your property.
Benefits
Flood Hazard Studies
Clarity where maps are silent
Many streams are unmapped or only broadly studied. A flood hazard study fills that gap with a site-specific analysis of the risk.
Better decisions on placement and design
A clearer picture of flood risk helps you place and design structures more deliberately and avoid the most vulnerable areas.
A foundation for other work
A flood hazard study can underpin design, permitting, or even a map revision. It's often the analytical groundwork the rest of a project stands on.
A site-specific analysis of flood risk
We analyze the hydrology and hydraulics of the stream or water body affecting your site, using a modeling approach suited to the situation. We define the flood risk, such as flood elevations and extents, at the level of detail your decision requires. You receive a study that clarifies the flood picture for your property, whether the goal is informing design, supporting permitting, or laying groundwork for a map revision. If the existing mapping is the issue, the study can also establish the basis for the next step.
Use Cases
A flood hazard study fits when you need to understand flood risk that the maps doesn't adequately capture.
01
Your stream isn't well mapped
The water body affecting your property is unmapped or only broadly studied. A flood hazard study defines the risk at a useful level of detail.
02
You're siting a project near water
You need to know the flood risk before placing structures. A study informs where and how to build safely.
03
You need groundwork for other steps
Design, permitting, or a map revision depends on defining the flood risk first. A study provides that analytical foundation.
Tips and FAQs
A flood hazard study's detail scales to your needs, from a planning-level picture to a detailed analysis supporting design or a map revision. It relies on hydrologic and hydraulic modeling, and the quality of available topographic and stream data influences the results. Because these studies often feed into other work, it's worth being clear about the end goal up front so the analysis is scoped to match.
When would I need a flood hazard study?
You may need one when FEMA mapping does not adequately define the flood risk—for example, when a stream is unmapped, the data are outdated, or a decision requires finer detail.
How is this different from FEMA mapping?
FEMA mapping provides regulatory flood zones at a broad scale, while a flood hazard study offers a site-specific analysis, often at greater detail or where mapping is absent.
Can a study support a map revision?
Yes. A flood hazard study can provide the technical basis for a FEMA map revision, which is a related service we offer.
What data do you need?
Typically topographic and stream information, along with hydrologic data for the drainage area. We identify what's needed and can arrange for it as part of the work.
