Timing is Everything: How Seasons Impact Your Flood Risk Survey (and Your Deadline)

Before we even think about sending a surveyor to the site, every project begins with a rigorous data review and collation of information. We review GIS workspaces and open-source data platforms to see if a model already exists for your location.

Once we have the data, we perform a diagnosis and health check. We ask:

• Is the model credible? When was it built?
• Has the landscape changed? Are there new structures, bridges, or housing developments nearby?
• Does it meet current standards? The Environment Agency (EA) guidance states that hydrology for models older than five years should be updated to current standards. 

If the area has changed significantly or the model requires extension, we often need new topographic or channel surveys to capture accurate profiles.

Is there a “perfect” time to survey? Yes. Conversely, there are times when getting accurate data is nearly impossible. Working closely with Storm Geomatics, we have identified two major factors that can derail a schedule:

1. High Water Levels (The “Winter” Problem) If a river or watercourse is in flood, we cannot capture the bank profile accurately. Surveys simply cannot progress until water levels recede enough for the team to safely and accurately profile the channel and associated banks.
2. Vegetation (The Summer Problem) Dense vegetation is more than just a nuisance; it’s a barrier. If a river bank or ditch is heavily overgrown, our teams may not be able to access the channel at all. In these cases, works must pause until vegetation is removed, adding unexpected delays and costs to your timeline.

To help you plan, Storm Geomatics has developed a calendar identifying the optimum times to survey and the months where you are most likely to face difficulties. (Note: We will explore this calendar in detail in our next post).

Our “Plan B”: How We Keep Moving When Surveys Stall

So, what happens if we hit these issues? If high water or dense vegetation stops the survey, Aegaea does not stop working.

We have a robust process to keep your project moving during survey delays:

• Satellite Remote Sensed Data: We source satellite data to build out the wider 2D floodplain domain, filtering and sense-checking the LiDAR data in the meantime.
• Hydrology First: We proceed with hydrology calculations while waiting for the survey to be sourced.
• Seamless Integration: Once the survey is ready, Storm Geomatics provides files in a format specifically designed for immediate upload into our modeling software, saving further time.

Additionally, Storm Geomatics provides photos of significant assets and inflows that might not appear on OS mapping or Google Earth, ensuring that when the data does arrive, it is comprehensive and accurate.

Don’t let the seasons dictate your deadline. By understanding these seasonal risks and planning your survey during the optimum window, you can avoid costly delays. Contact us today to start your project’s health check.