Floodplain Modeling & Mapping
Modeling how water behaves and where the floodplain lies
Understanding where a floodplain lies and how a project affects it takes hydraulic modeling of how water moves through a stream and its valley. Colman Engineering provides floodplain modeling and mapping for projects across Virginia, defining flood elevations and extents for planning, design, and review. It provides the technical foundation for much of our flood-related work.
Benefits
Floodplain Modeling & Mapping
See where the water goes
Modeling defines flood elevations and extents so you know where the floodplain actually lies. That clarity underpins sound siting, design, and permitting decisions.
Understand a project's effect
We can model how a proposed project changes flood conditions upstream and downstreamstream, helping shape a design that avoids worsening flooding for others.
Analysis that supports review
Floodplain modeling backs permitting, map revisions, and design approvals with defensible technical data. It gives reviewers the analysis they need to say yes.
Hydraulic modeling that defines the floodplain
We build a hydraulic model of the stream and floodplain using topographic and hydrologic data appropriate to the project. We define flood elevations and extents and, where relevant, model how a proposed project changes them. You receive mapping and analysis suited to your purpose, whether planning, design, permitting, or a map revision. Because this modeling underlies so much flood-related work, we scope it to serve the decision or approval it's meant to support.
Use Cases
Floodplain modeling and mapping fit when a decision or approval depends on defining flood behavior.
01
You're building near a floodplain
Your project sits near a stream or mapped floodplain. Modeling defines the flood elevations and extents you need to design around.
02
You need to show no adverse impact
Permitting requires demonstrating your project won't worsen flooding. Modeling quantifies the project's effect on flood conditions.
03
You're pursuing a map revision or study
A FEMA revision or flood study needs supporting hydraulics. Floodplain modeling provides that technical foundation.
Tips and FAQs
Floodplain modeling depends on quality topographic and hydrologic data, which shape both the effort and the reliability of the results. The modeling approach and level of detail depend on the purpose—for example, planning versus a regulatory submittal. Since this analysis frequently supports permitting or map revisions, aligning the modeling with those requirements from the start avoids rework later.
What is floodplain modeling used for?
To define flood elevations and extents and to evaluate how projects affect flooding. It supports siting, design, permitting, flood studies, and map revisions.
Can you show my project won't increase flooding?
We can model existing and proposed conditions to evaluate a project's effect on flood elevations, which is often what permitting requires you to demonstrate.
What data does modeling require?
Primarily topographic data for the stream and floodplain and hydrologic data for the flows. We identify what's needed and can help obtain it.
Does this support FEMA map revisions?
Yes. Floodplain modeling provides the hydraulic basis for map revisions and flood hazard studies, both related services we offer.
