The City of Houston recently revised its Chapter 19 ordinance dealing with building and development within the floodplain and now further restricts such activity. The City deemed this necessary as the previous ordinance was written in 1985 and because of the huge losses as a result of Tropical Storm Allison. The following specifically addresses remodeling of homes in the floodway and floodplain.
Tropical Storm Allison prompted a joint study between FEMA and Harris County Flood Control District. This study is referred to as the Tropical Storm Allison Recovery Project (“TSARP”). The study has generated a new flood map commonly referred to as the TSARP map and is slated to replace the current Flood Insurance Rate Map (“FIRM”) on June 18, 2007. This map expands the floodway and floodplain.
For clarification, the City defines floodway and floodplain as follows: The floodway is the primary conveyance area for storm runoff along a bayou, river, or other waterway and is located within the floodplain. The floodplain is the land adjacent to the waterway that stores and/or conveys water during a 100-year event (a rainstorm that has a 1% chance of occurring in a given year) that cannot be conveyed within the banks of the waterway.
How does the new Chapter 19 ordinance affect a homeowner in the City of Houston whose property lies in the floodplain and/or floodway? The following is a brief outline how it affects such situations.
A home in the floodway can be remodeled but the limitations include that the remodeling cost not exceed 50% of the value of the structure (referred to as “Substantial Improvement”) and that there is no increase to the home’s footprint. However, a second story addition would be allowed.
A home in the floodplain and not in the floodway can be remodeled and can have an addition to the footprint providing the following conditions are met: (1) the cost of the addition is not a Substantial Improvement; (2) the finished floor is 12” above the Base Flood Elevation (“BFE”); (3) the addition must not remove storage capacity from the floodplain.
Item (3) is where the ordnance rules get complicated. If the property is located well above the BFE then the addition would be allowed. If not, then the addition must either be built on pier and beam and allow water to flow under the structure or you must mitigate.
Mitigation is replacing the flood storage capacity lost by building the addition. The mitigation must be on the property or located within one-quarter mile from the property in the same watershed. The revised ordnance requires that mitigation be designed by a qualified engineer to insure for long-term protection of the mitigation. It also requires that the location of the mitigated areas and their volumes be recorded on the plat and deed of the property. This will insure that the mitigation will be permanent and will transfer with the property, as it is sold over time.
The City’s revised Chapter 19 Ordinance is 38 pages and is substantially more detailed and is available at:
www.publicworks.houstontx.gov/planning/cityengineer/floodplain.htm
Tom Pellegrin, CGR is a partner with Heritage Construction Services. |
