The City of Houston should take a much more aggressive posture with regard to flooding and protection of its citizens.  This should include many different aspects.  Here are some examples. 

1. Flood Warnings.  A flood warning system should be established for the entire City.  Radar imagery can be used to estimate rainfall intensity.  Combined with flow gages on the various creeks and bayous, this radar imagery can provide the centerpiece of a flood warning system that can at least give residents advance notice that a flood may be coming so that they can get an hour or two advance notice.

2. Road Warnings.  Roads are the secondary drainage system in Houston.  Some roads flood much worse than other roads.  Intersections and road segments that routinely flood should be identified and marked.  When major storms come, the City should attempt to block off certain areas, such as underpasses that routinely flood. 

3. Information on Surviving a Flood.  Several people were electrocuted during the Allison flooding.  The City should prepare a list of dos and don’ts regarding surviving a flood in your home, including advice such as shutting off the electricity to your entire house rather than attempting to unplug electrical items with floodwaters in your house.

4. Flood Plain Maps.  Flood plain maps change.  In White Oak Bayou and other areas, the flood plain maps had changed to increase the area within the 100-year flood plain.  However, many of the people in these areas had no knowledge that the maps had changed.  The City should have gone into these neighborhoods and advised every homeowner whose property was added to the 100-year flood plain and 100-year floodway that the map had been changed and that they were now in the flood plain or floodway.  Such notification never occurred and many people who were in the flood plain did not purchase flood insurance because they did not know that they were in the flood plain.

5. Flood Insurance.  The City should advise all residents to purchase flood insurance.  Substantial portions of the flood victims from Allison’s rainfall were not in any mapped floodplain.  Our streets are the secondary drainage system.  Once the streets fill up, the water runs into yards and down the streets into low areas.  Virtually any area of Houston can and may flood.  All residents should have flood insurance and the City of Houston should advise residents of this fact.

6. Upstream Development.  In many areas such as White Oak Bayou, flooding was caused by upstream development that was not properly regulated and controlled by Harris County.  Given that the City of Houston lies downstream from much of the developing portion of Harris County, the City of Houston is particularly vulnerable to the decision-making of Harris County.  The City of Houston needs to have a knowledgeable presence with regard to flood plain modeling and the impacts of upstream development on the City of Houston’s neighborhoods.  Such action is not occurring at this time.  It is doubtful that the City of Houston currently possesses such capability and it needs to have this capability.  For the most part, the City of Houston has been “missing in action” with regard to flood modeling and the impact of upstream development on neighborhoods adjacent to bayous.  That must change.

7. Change the Loopholes.  No more development should be allowed to occur if there is no flood retention provided for that development.  In some areas, developments of less than 10 acres in size are exempt from the requirement to provide on-site retention, even if the stream or bayou cannot handle a 100-year flood.  That must change.  Incremental increases in flood levels occur even with small developments.  We must stop the increase in downstream flooding.

8. Change the Attitude.  Perhaps most importantly, the City of Houston needs to adopt a position that it has a major role to play in helping its citizens understand flooding and surviving flooding.  Flooding is a reality in Houston.  We must learn to protect ourselves better.

9. Buy-Outs.  Buy-outs of homes that have flooded more than one or two times make sense.  Buy-outs must be fair and they must be comprehensive.  Most importantly, the land upon which these houses are located must be converted to permanent open space and/or flood control purposes.  They should never be redeveloped for housing or commercial uses.

10. Rebuilding in the Flood Plain and Floodway.  Federal and local rules require that a flooded home in the 100-year flood plain must be elevated above the 100 year flood level if it is damaged more than 50%.  A home in the floodway may not be allowed to be rebuilt if it is damaged more than 50%.  These rules make sense, although they are harsh.  However, the City of Houston is doing no one any favors by advising people on how to circumvent these requirements.  We all will suffer if we allow rebuilding to be undertaken in a manner that worsens flood damages in the future.

11. Reconsider the 100-year rainfall event.  The 100-year rain event for the Houston area is 12.5 inches in 24 hours.  There have been at least two events in the last two decades that have substantially exceeded this amount.  Because all of our planning is based upon the 100-year flood which is generated by the 100-year rain, if the 100-year rain is too small, our 100-year flood plain will be too small.  We need to seriously examine this 100-year rainfall number and adopt a larger rain for planning purposes in this city.