03 OCTOBER 2017
7 Frequently Asked Flooding Questions After Harvey
After an unprecedented event like Hurricane Harvey, many are left in its wake wondering "what's next?"
For architects, designers and planners, the answers to all questions aren't fully known, but from an architect's perspective, Kirksey will try to offer responses to some of the most frequently asked questions after Harvey. For our beloved Bayou City, Houston is as resilient as it is water-prone, and we believe it —
and its people —
will bounce back stronger than ever.
, Kirksey’s Director of EcoServices, Executive Vice President and LEED Fellow, helps answer some of the most frequently asked questions in the wake of Harvey:
1. When does it make sense to rebuild like-for-like, rather than undertaking a significant renovation (such as raising the foundation) or demolishing and re-building from the ground up?
This is a judgment call that a property owner must make, based on life safety and budget. If a property has only flooded once by a few inches and is not in or next to an existing floodplain or flood pool, rebuilding with minimal changes may be an acceptable approach. We highly recommend replacing porous materials such as wood, carpet and drywall with non-porous flood-resistant materials.
For buildings that suffered feet of flooding or are located in an existing or likely future floodplain, it makes sense to consider a major renovation or replacement incorporating significant stormwater mitigation strategies.
2. When does it make sense to throw in the towel and relocate?
Again, this is a judgment call based on life safety and budget. A reasonable approach would be to consider relocating instead of renovating if a property is located within the 100-year floodplain, or has flooded several times.
3. What re-building work requires a city permit?
Building permits must be obtained for commercial buildings, whether renovations are extensive or not. Building permits are also required for FEMA funding. Both commercial and residential buildings that are re-building like-for-like are not required to comply with current building codes.
Residential buildings in the City of Houston:
• May have some work done without a permit. See here for more information.
• Will require a Floodplain Development Permit if located within the 100-year floodplain or floodway. If “substantially damaged,” meaning that the cost of restoration would be 50% or more of the pre-flood value of the building itself (excluding land), then the building will have to be rebuilt to meet Floodplain Performance Standards, from the City’s Code of Ordinances Chapter 19
. Summary information can be found here.
4. What flood repair work requires compliance with TDLR (Texas Department of Licensing and Regulation)?
All work is required to comply with the Texas Department of Licensing and Regulation’s Architectural Barriers Texas Accessibility Standards (TAS). However, if a project’s total estimated cost is less than $50,000, it is not required to submit the project to the Department for registration and review. Consult with your Registered Accessibility Specialist to make sure they are in agreement with the proposed compliance strategy for your renovation work. Note that this standard applies only to commercial buildings.
5. What do the floodplain maps (such as HCFC) mean now? Will they be updated, and what do we do in the meantime?
Floodplain maps will be updated, but this is a process likely to take years. FEMA’s website
lays out a process for Physical Map Revisions for flood risk zones, floodplain and floodway delineations, and flood elevations that takes 18 months. This process can become politically contentious and be further drawn out.
Before the maps are updated, property owners should be cautious about using the current, now outdated, floodplain designations to assess risk. Instead, check the high water mark nearest to the building, and consider building as high above that as is practical.
6. What should I do about mold?
Homes that have flooded are very likely to have problems with mold. Texas has extensive laws
regarding the official assessment and remediation of mold. These laws require that those who identify mold and those who remediate mold are different parties, each with their own licensure procedures. Texas laws related to mold are designed to protect property owners.
Homeowners and building owners in Texas are allowed to undertake their own mold remediation. Homeowners who do their own mold remediation may want to hire an independent consultant to conduct a post-remediation inspection to verify that the home is mold-free after treatment. This will be needed if they are considering selling the property. The EPA offers guidelines for homeowners
who wish to remediate mold themselves, and for commercial buildings and schools
seeking to use contractors for this work.
Harmful bacteria and chemical contaminants are carried in floodwaters and have been found in higher concentrations in sediment left behind in buildings. Homeowners should ventilate their home by opening doors and windows and wear protective equipment (gloves and facemasks) while removing sediment and absorptive materials that have been in contact with flood waters.
7. What are Kirksey’s top recommendations for future flood resistance?
For new buildings, we recommend working with your architects and engineers toward a goal of flood resistance to a Harvey-like event. Every building and site is different and will have different flooding and resiliency concerns that should be addressed in the earliest conceptual design phase of any project. We recommend allotting more time for due diligence with respect to site selection and project feasibility to research resiliency issues.
In general, it makes sense to build as high as is practical – above the local high water mark. For residential buildings, one sensible approach might be to use pier and beam construction.
For both new and existing buildings, also consider providing more detention storage than code currently requires – ask your civil engineer to analyze the flood gauge data from the largest rain event near your site, and size detention to accommodate it. We recommend low-impact development strategies
for stormwater detention; these both slow water flows down, mimicking nature, and provide necessary habitat for local wildlife.
For both new buildings and renovations, an alternative to raising the foundation is to design the first floor of the building as flood-resistant, including:
• Using non-porous finish materials such as polished concrete or terrazzo for flooring
• Including no fixed millwork
• Providing a non-porous wainscot, such as tile, up to above flood level
• Raising all mechanical and electrical equipment above the 1st floor
• Providing flood gates and doors
Experienced flooding? Looking for future flood mitigation designs?
If you’re a commercial building owner who is renovating or building new for future flood resistance, Kirksey’s highly-skilled architects and designers have the expertise to help.
Give us a call or send us an email here.