Taking a First-Blush Look at Flood Risk.
Many times, we are asked for a quick, initial assessment of potential environmental red-flags when assessing real estate on behalf of Clients, be it related to a potential purchase, a sale, financing, land planning and development, the necessity to secure specialized insurance, or the like. These are not in-depth studies, which follow in many cases, but simply a first-blush look.
That assessment can veer toward 'brown' issues - namely related to potential hazardous material/waste contamination; 'green' issues — namely related to natural impacts, such as wetland and flood hazard impacts, or both.
To satisfy these requests, we need reliable, easy-to-access, tools to help us gather information quickly, so we can process same and provide guidance to whomever is looking to make a business decision with an environmental angle attached.
This article focuses on one of those green issues — the potential for flood hazard.
In the past, one of the standard, go-to resources to quickly assess flood risk would be to review a federal Flood Insurance Rate Map (FIRM) that encompasses your subject property. These FIRM maps detail the extent of a 100-year flood, also known as a base flood (i.e., flooding that would likely occur once in one hundred years, or equivalently, having a 1% risk of happening in any given year), the 500-year flood plain and areas that have not experienced any flooding (i.e., outside of these 100-year and 500-year lines).
FIRM maps are readily available online from the Federal Emergency Management Agency (FEMA) and they cover a large portion of the contiguous United States. However, there are some inherent limitations in using FIRM maps to make fast, flood-related decisions regarding a parcel.
The limits are, in no particular order are:
There are large segments of the United States for which FIRM maps are not available, including most of Alaska, a large portion of Maine, and a significant, vertical swath of inland states across the Midwest;
For areas that are mapped, some of the flood-related data hasn't been updated in a decade or more — much of it is at least 5 years old (refer to the date contained on the FIRM map panel you reference);
The flood information does not take climate change into consideration; and;
The maps are considered a 'snapshot' of conditions at the time the map was produced — think of it as an ever-aging photograph, reflecting current site and areal conditions less accurately with each passing day.
These FIRM maps still provide valuable information, but the limitations of the information need to be fully understood, or you may be making decisions with a false sense of security with respect to flooding risk.
Enter the new kid on the block, offering a powerful, cutting-edge tool for your toolbox.
First Street Foundation (FSF) is a non-profit dedicated to assessing flood hazard risk on an individual property basis, taking into consideration climate change, rainfall-related flooding and updated modeling based upon scores of documented, recent storm events and the effects of same in various areas across the country. Located, appropriately enough, at 247 Water Street, in Brooklyn, New York, FSF is comprised of over 80 scientists, modelers and researchers that plug the aforementioned data into sophisticated modeling systems, and reportedly develop more accurate, and up-to-date flood-related information.
Due to this effort, FSF has opined/concluded:
Approximately 142 million individual properties exist in the contiguous United States and are contained in the FSF modeling database;
Of those parcels, FEMA believes approximately 8.7 million are subject to base flooding; however FSF believes the overall number is closer to 14.6 million (over 10% of all the real estate in the country) - due to updated modeling and taking documented climate change patterns into consideration;
Meaning that 6 million more individual parcels across the United States are subject to substantial flooding risk according to FSF - these are sites not captured in the current set of FIRM maps; and
In the next 30 years (by 2050), an additional 2 million parcels will become subject to substantial flooding.
This disparity between FSF and FIRM flood mapping has manifested itself in recent insurance and federal flood claims; namely, a full 40% of recent claims for flood-related relief encompass parcels that are not captured on existing FIRM maps. Let that fact sink in the next time you believe you are in the clear simply because a FIRM map didn't highlight your parcel as at-risk.
Although you would think a majority of these flood claims come from coastal areas (such as Louisiana and Florida) — which they do — they also derive from less obvious locales, such as Texas, Illinois, Oregon and Pennsylvania, among other states.
All this FSF flood data can be easily accessed at www.floodfactor.com; you simply enter an address, city and zip code, and the resultant data provides:
Information on the current flood risk factor for the selected parcel (rated on a 1-10 scale);
The expected change in flood risk over the next 30 years;
Areas prone to flooding in the immediate vicinity of the property in question — mapped on low-flight color aerials; and
The overall flooding conditions in the county in which the parcel is located.
The information is quick to load, easy to understand and, importantly, the cost is...free.
FSF has also just published a 2020 National Flood Risk Assessment report, compiled by state, detailing regional trends and flooding patterns. It is another valuable resource, also free to access on their website.
Our recommendation?
Certainly don't abandon FIRM maps, use them, but understand and factor their inherent limitations. Then augment them with the FSF model platform and use their up-to-date mapping to secure a quick, first-blush look at whether a parcel deserves a more detailed flood-related assessment. Both resources are fast, easy...and for now...free.
The bottom line.
Many more sites will need to weigh a flood risk component when determining and quantifying overall environmental impacts, even sites that, at first blush, might not be so obvious to contain such a water-related risk.