FEMA published a predictive model for flooding during Harvey - was it accurate?

On August 27, 2017 FEMA published a Damage Assessment Model listing predicted inundation depths and degrees of damage at the level of individual land parcels throughout the Houston area.  The methodology by which this was produced is  described in a document at the link below:

https://data.femadata.com/NationalDisasters/HurricaneHarvey/Data/DamageAssessments/

Although the publication of this model was too late to guide study area resident decisions concerning preventive measures and evacuation, it does provide an illustration of areas and structures potentially at risk during another major rainfall event.


Particularly notable is the concentration of points in the Brookwood neighborhood adjacent to Armand Bayou.  Information to be presented in a future post shows that damage was relatively light in that area.  However there were significant numbers of flooded parcels throughout Clear Lake City that were not predicted by this model.

Does this model provide any insight regarding flooding that occurred in your area?  Perhaps it points out where attention to drainage mitigation could be focused.

Comments

Post a Comment

Popular posts from this blog

Considerations for neighborhood protected by levee

Image
Residents and potential home buyers in areas where protection from flooding is provided by levee systems may need to consider carefully the actual risk, which may be higher than many assume.  Levees are designed to reduce (but not eliminate) flooding risk.  There may often be no requirement for residents to be provided with an assessment of the specific risk by developers. However, the presence of levees indicates that significant drainage issues exist in the area. The levee system (usually composed of earthen berms, flood gates, and pumps) must perform two functions successfully to prevent flooding: Hold back flood water from outside of the protected area Remove water accumulating inside the protected area Failure of the levee system can result from multiple factors such as: Berms must have sufficient height and strength to hold back impinging flood water Gates must operate properly and be opened/closed at the appropriate times  Pumps must operate properly ...
Read more

Check flood control and drainage improvement projects in your area

Image
Residents of flood prone areas are well advised to stay informed regarding current and planned flood control and drainage improvement projects.  These projects by design will result in significant reductions to flooding risk.  In some cases the flood hazard maps will be revised to reflect the reduced risk.  This could allow a decrease in flood insurance premiums for the home owner. In my area I noted a project underway in Nassau Bay, a waterfront community in southern Harris County, Texas that has a history of repetitive flooding.  The project is being conducted by Harris County Flood Control District (HCFCD).  It is located on a lot that I had noted previously as the site of a home buyout and demolition after Hurricane Ike, which caused heavy damage to many Nassau Bay homes in 2008. HCFCD maintains an interactive map viewer on which the details of all Maintenance and Capital Improvement projects can be viewed at the link: https://www.hcfcd.org/int...
Read more

Drainage features without mapped flood plains

Image
All drainage features whether natural or man-made have flood plains, which are simply the adjacent low areas that fill with water during periods of overflow.  Water overtopping the banks will move to all connected lower areas and remain until drained away by other features.  However, these areas may not be mapped as flood plains on Flood Insurance Rate Maps (FIRM).  As a result, residents and property owners may not realize that they are located in a flood zone. Although unmapped these areas will flood during times when the nearby drainage features overflow. This issue was featured in an April 1, 2018 front page article in the Houston Chronicle article entitled "Damage outside flood plain exposes flaws - 'We just need to start again,' says professor about maps designating flood-risk areas".  The article was written by David Hunn, Matt Dempsey, and Mihir Zaveri and can be viewed at the link below: https://www.houstonchronicle.com/news/article/In-Harvey-s-delu...
Read more