Sunday, August 31, 2008

The Woodlands annual encounter with major hurricanes

OK, so The Woodlands does not have an annual encounter. It sure seems that way! Hurricane Rita caused great alarm just yesterday, or was that three years ago? For sure, these encounters raise our awareness of the potential destruction of such a storm. Here we are in the great piney woods of east Texas, away from the coast. We know we are not exempt from the power and destruction of a hurricane. The classic threat is from a dangerous hurricane approaching from the southeast and hitting the coast just south of Galveston where we would get the northeast quadrant of rain and wind. However, this year we are looking at a very different scenario in hurricane Gustav. Not only that, there is a second storm Hannah moving west and seemingly positioning itself to follow a similar path.

Gustav is heading towards Louisiana. That usually means, lower your guard, there is no problem for us. This time one model presents itself as a threat just two days before the storm is predicted to reach the continent. Observe the left-most model predicion. The left model crosses the coast just north of the Houston area and passes right over us in The Woodlands. Moving at 15 MPH, on this path, the storm would reach us in a few hours packing very strong winds. This is a very nontraditional path. The other models predict the storm to move west at some given point as well, so we can expect breezy conditions from any of them and lot of rain.

Are we threatened by flooding conditions? That threat is certainly possible. The Woodlands has two creeks to watch. Presume for a minute we get a torrential downpour of 15 inches. That is not likely with this storm now but if it stalls over us, we can get 30 inches! That will flood our area badly. How do you prepare for a flood? It is difficult, much more so when you own a one story home. There is no place to go but up after the flooding conditions start. Driving out of it is not a good idea. Often you will get into more serious trouble than by staying at home.

If you do not have flood insurance, you are out of luck per Texas legislation (last time I checked). Once a storm enters the Gulf of Mexico, new policies are not issued until the Gulf is cleared of storms and there is no imminent threat of flooding.

If a flood does occur and you are in your home, you want to arrange your belongings in such a way as to protect those that could be seriously harmed by water by carrying them to the highest places in the home. That would include all electronic devices such as TVs or computers. Place those things that are not treasures or expensive on the floor to make space for things that need to be stored higher. Remember that you may live a day or two upstairs if we get a Noah's flood fro such a storm. It takes many hours for it to subside because of the size of such a storm. Also, we can be downstream from the main watershed area of rains and still get flooded.

Where would you drive to exit The Woodlands to higher ground? I would go down Woodlands Parkway to 2978, one of the highest places near here. On I45 is also safer if you can get there. However, the Grogan's Mills area is more prone to lowland flooding than the western side of The Woodlands. Areas near Spring Creek should be avoided. In the past, the areas adjoining the creek have proven to overflow and turn into a lake, reaching into Panther Creek and Indian Springs. I would expect by looking at the topographic maps, that flooding would occur more so in the new Creekside Park Village.

Elevations in our area - You can access this information easily from Google Earth which gives the elevation of the point you are looking at. For example, I entered my address and got the elevation of my home - 165 feet.
+Spring Creek elevations - 110 feet near The Woodlands.
+Interstate 45 ground level - 130 feet, slightly higher in Grogan's Mill next to the freeway and less in Oak Ridge.
+Town Center - 145-150 ft
+Lake Woodlands 125 ft
+Woodlands Pkw/E Panther Ck - 143 ft, /Gosling - 165 ft, /Kuykendahl - 175 ft, /W Branch Crossing - 190 ft, /2978 - 204 ft
+College Park(242)/Greenbridge 142ft, /Alden Woods - 150 ft, /Gosling - 154, /Montgomery College - 140 ft, /Donwick Dr - 125 ft
+Bear Branch Creek near TWHS - 140 ft, Bear Ck Reservoir - 145 ft
This should give one an idea of how water might flow in any given Noah's flood. It will simply seek the lowest point. The creek beds are the natural collector of water, so expect them to swell and overflow causing the greatest damage.

Don't put your guard down on this particular storm until it is gone. It can come back.

Useful references
Wunderground Weather for current detailed tropical forecast information
National Hurricane Center
Related Article on the classic scenario