Hydraulic Flood Modeling for Any Global Region
Riverine, coastal, and pluvial flood analysis for technical teams that need defensible results without starting from a months-long engineering study.
Degree Day provides custom flood modeling and flood-hazard analysis for sites, corridors, watersheds, coastlines, and regional study areas.
We model three major sources of flooding:
- Riverine flooding from rivers and streams
- Coastal flooding from tides, storm surge, waves, and sea-level rise
- Pluvial flooding from intense rainfall, ponding, and overland flow
The goal is flood information that can be reviewed, questioned, and used in real technical decisions.
Between a hazard score and a full engineering study
Many decisions need more than a generic hazard score or a static public flood map, but less than a months-long engineering study. Degree Day works in that middle space.
Typical questions include:
- Is this site exposed to riverine, coastal, or pluvial flooding?
- How deep could flooding plausibly be under a specified design event?
- How do results compare with FEMA, national, or commercial flood datasets?
- How might exposure change under sea-level rise or heavier rainfall?
- Which assets need more detailed engineering review?
- What assumptions are driving the result?
Three sources of flooding, modeled consistently
Riverine Flooding
Flooding from rivers and streams that overtop banks and spread across floodplains.
Useful for evaluating watershed-scale flood exposure, river corridors, infrastructure crossings, and sites near mapped or unmapped floodplains.
Coastal Flooding
Flooding from tides, storm surge, waves, elevated sea levels, and future sea-level-rise scenarios.
Useful for evaluating coastal assets, ports, shorelines, low-lying districts, and infrastructure exposed to present-day or future coastal water levels.
Pluvial Flooding
Flooding from intense rainfall, ponding, and overland flow.
Useful for evaluating urban surface-water flooding, access roads, equipment pads, substations, warehouses, and low-lying areas outside mapped river or coastal flood zones.
Extreme rainfall, Dubai (April 2024)
Pluvial flooding often appears outside mapped river and coastal flood zones. This run models the April 2024 Dubai extreme-rainfall event, with drainage and flood defenses represented.
Decision supported Identify low-lying areas, access issues, and assets that may need drainage review or more detailed engineering analysis.
Reduced-physics modeling, matched to the decision
Degree Day uses SFINCS, an open-source reduced-physics hydraulic model from Deltares, a leading institute for applied water and flood modeling. It excels where many simulations are needed across large areas, and like any reduced-physics model, it is not right for every problem.
Model setups account for drainage and flood defenses, and are built on lidar DEMs where available. Our role is to match the setup to the decision, and to document where results are appropriate, uncertain, or screening-level.
- Regional flood mapping
- Scenario testing
- Early-stage due diligence
- Multi-site or corridor screening
- Riverine, coastal, pluvial, and compound flood analysis
- Comparing custom scenarios against existing public or commercial maps
- Final engineering design
- Structure-scale hydraulics
- Complex wave-driven coastal processes
- High-energy coastal environments
- Poor terrain data or unknown drainage conditions
- Regulatory determinations requiring approved local methods
100-year flood, South Skunk River, Iowa
When a river tops its banks, the damage happens across the floodplain, not just at the channel. This run models a 100-year flood on Iowa's South Skunk River, tracing how far the water spreads, how deep it gets, and which sites sit in its path, including areas public flood maps miss or draw inconsistently.
Decision supported Evaluate flood depth, extent, and asset exposure where public flood maps are missing, outdated, or do not cover the scenario you need.
Present-day hazard, and transparent future scenarios
We can evaluate present-day flood hazard, or transparent future scenarios based on:
- Sea-level rise
- Changes in extreme rainfall
- Changes in river flow or runoff
- Storm surge scenarios
- Global warming levels
- Emissions pathways
- User-defined stress tests
We do not treat future flood maps as exact predictions. Instead, we use climate information to build transparent scenarios, test sensitivity, and identify where flood exposure may plausibly increase.
Sea-level and surge scenario, Miami, Florida
Coastal flooding depends on water levels, tides, storm surge, waves, local topography, vertical datum treatment, sea-level-rise assumptions, and coastal defenses. This sample shows modeled coastal inundation under a specified sea-level and surge scenario.
Decision supported Compare present-day and future coastal exposure while keeping the water-level assumptions, datum treatment, and model limitations visible.
The map is only half the deliverable
Spatial Outputs
- Flood depth rasters
- Flood extent maps
- GIS-ready scenario layers
Technical Outputs
- Methods documentation
- Model setup summary
- Assumptions and limitations
Decision Outputs
- Asset-level depth tables
- Scenario comparisons
- Recommended next steps
Each project documents what was modeled, what data were used, what assumptions were made, and how results should be interpreted.
- Flood depth map
- Flood extent map
- Asset-level exposure table
- Scenario comparison
- Methods memo excerpt
- Assumption and limitation notes
Designed for regional problems, not just single sites
Traditional hydraulic studies are built around a single site or local jurisdiction. Our workflows produce comparable flood information across many locations at once, especially where public flood maps are unavailable, outdated, or inconsistent.
- Regional study areas
- Coastlines
- Watersheds
- Infrastructure corridors
- Multi-site portfolios
Research-grade methods, applied to real decisions
Degree Day is led by D.J. Rasmussen, PhD, a climate and hazard scientist with experience at NOAA, WSP, and Arup, and a publication record spanning climate extremes, coastal risk, flood exposure, and applied climate-risk methods.
Degree Day brings that research background to practical flood-risk questions: careful assumptions, reproducible workflows, clear uncertainty communication, and outputs that can survive technical review.
Request a Sample Package
The best way to evaluate flood modeling is to inspect a full deliverable, not just the maps. Request a sample package with a flood depth map, asset-level exposure table, scenario comparison, and methods memo excerpt. We can also scope a short pilot study for a site, corridor, watershed, coastline, or regional study area.
