Ever wonder how close you are to the floodway, 100-year flood plain or 500-year flood plain? Ever wonder why so much sand winds up in the river after a flood? To learn how flood hazards affect your home or your friendly, environmentally responsible, neighborhood sand mine, consult FEMA’s Flood Hazard Viewer. It’s fast and easy, but has a few quirks.
How to use Flood Hazard Viewer
- Click on the link above to go to FEMA’s Flood Hazard Viewer entry page.
- Type in an address to zoom to a location. Or zoom manually by clicking on your area of interest.
- Eventually the background changes from a U.S. map to a satellite view.
- Zoom and scroll until you find the location you are interested in.
- Wait for a few seconds while the website merges information from its map and flood databases. Then suddenly, voilà, there it is.
- Lines and colors pop up over the satellite image, as you see below.
- Display the legend by clicking on the parallel bars in the upper right of the screen.
- Use the measuring tool to calculate area and distance.
In the example below, I was looking for the sand mine north of Kingwood on the East Fork to see if it was in the floodway. I also wanted to see how big it was. This mine measures more than two miles from north to south and occupies approximately 750 acres – five times the size of East End Park. The mine’s stockpile alone (circled in red) occupies about 34 acres. That’s a pretty big sand box.
It took me all of a minute to figure all of this out. I wish the sand miners had taken that much time when deciding to locate their mine here.
What You Can Tell from Flood Maps
What can you tell from looking at a map like this? For one thing, the owner of that mine likes living dangerously. I hope he was wearing his Huggies when Harvey hit.
The mine sits at the confluence of not one, but two different floodways – the cross-hatched areas over Caney and White Oak Creeks. In fact, more than half the mine sits INSIDE the floodways. But, hey, that’s where the sand is easy to get.
Easy come, easy go!
The sand mine’s stock pile bridges the 500-year (peach colored) and 100-year (aqua colored) flood plains. It is much taller than the surrounding trees as you can see in the photo below. But it was no match for the Harv.
The Force of Harvey
According to Harris County Flood Control’s final report on Hurricane Harvey, the peak discharge on Caney Creek was 21,100 cubic feet per second (cfs). That wasn’t nearly as much as the 150,000 cfs on the West Fork, but it was still enough force to rip massive trees out of the ground by their roots. So I’m pretty sure it could have picked up grains of sand, contrary to TACA’s assertions. As My Cousin Vinny said, “Do you think the laws of physics cease to exist within your sand mine?”
From a business point of view, stockpiling your product at the confluence of two floodways is like a bank stockpiling money on a sidewalk next to the county jail. Probably not a smart move from a loss-prevention point of view.
Below is one of several massive sand dunes that appeared downstream from the mine during Harvey. This one is opposite East End Park and fills half the river. Note how the sand reaches into the tree tops.
Dunes like the one above can exacerbate flooding by reducing the carrying capacity of a river or stream. According to Harris County Flood Control, 1162 Kingwood homes and another 128 in Huffman flooded in the East Fork watershed during Harvey.
Laws of Texas vs. Laws of Economics
But alas, apparently there are:
- No State laws about locating a sand mine in a floodway – at least in this part of Texas.
- No State laws that dictate the separation between a mine and public drinking water source like there are in other states.
- No laws in this part of Texas that make miners retrieve their sand or pay for cleanup costs.
Perhaps if they had to pay $70 million for dredging, they might move their mines to less risky locations.
You Pay; They Play
Instead, public tax dollars will pay for the cleanup. Somehow this just doesn’t seem right. It’s like gambling, but you never have to pay the State House if you lose. Wish I could get those odds in Vegas.
TACA has one of the largest lobbying efforts in the State. They just pleaded with their members at their annual convention in San Antonio to double their lobbying budget – specifically citing PR problems on the San Jacinto in Kingwood.
But we must not have them all that worried. Featured activities at the convention were golf, mountain biking and handgun classes…while you were fighting contractors, still trying to put your home back together.
They have bucks. We have votes. Let’s use them. Make sure the candidate you vote for pledges to move sand mines back from the rivers.
Posted 7/7/2018 by Bob Rehak
312 Days since Hurricane Harvey