Steady northward migration of the San Jacinto West Fork could threaten the proposed new high-rise Kingwood Marina development – within the lifetime of many residents.
An analysis of satellite and aerial imagery in Google Earth shows that the river channel has shifted 758 feet north in 40 years – almost 20 feet per year – toward the site of proposed 25-50 story high rises. The proposed Kingwood Marina site is on the cutbank side of the West Fork. And the West Fork is definitely cutting.
Measuring River Migration Rate
These three images tell the story.
The migration of the river toward the high rises should continue. The river appears to be moving back toward one of its old meanders. The developer plans to build the high-rises in the old river bed. That’s a dangerous practice, because during floods, as residents all over Harris County discovered after Harvey, water seeks to return to old channels.
Floodway Shifting, Too
As the river moves closer to the high-rises, so will the floodway. Right now, the high-rises are built on the edge of the floodway that was mapped after Tropical Storm Allison in 2001. However, I believe that upstream development, river migration, and sedimentation are causing the floodway to expand and shift north. If current plans are approved “as is,” structures, people’s lives, and investor’s money will all be at risk.
Already at Greater Risk than Town Center
Harvey inundated Kingwood’s Town Center area. That’s a mile further from the river and on higher ground. About a year and a half later, approximately 25% of the businesses in Town Center still have not returned. That would certainly affect the economics of this development if it ever floods.
50 Years or Bust
At the current rate of northward migration, the river could reach the marina in about 50 years; it’s currently about a 1000 feet away. If the river “captures” the marina (just as it captures sand pits), we could expect to see a rapid shift in river migration toward the high rises. See the demonstration in the video below.
Of course, before that happened, someone would try to prevent it. The owners would push to “shore up” the development with bulkheads or levees.
Futile Struggle to Combat Nature
Bulkheads didn’t work very well for these people on Marina Drive in Forest Cove.
Levees have their own set of problems. And anyway, how do you put a level around a marina? Seems like building this close to the river is just asking for trouble.
Planned Construction Level Likely to Flood Every 4-10 Years
The developer wants to build the foundations up to 57 feet. That’s asking for trouble, too.
If you go back and analyze the crest data for the West Fork for the last 90 years, you will see that the river has crested higher than 57 feet nine times – once a decade. But you will also see that it has crested higher than 57 feet six times in the 25 years since 1994 – about once every FOUR YEARS!
Rivers! Look pretty. Get ugly.
Sometimes rivers remind me of that classic 1983 teen flick called War Games staring Mathew Broderick and Ally Sheedy. The duo hacks into a Department of Defense Computer and starts playing what they think is a game. It’s called “Global Thermonuclear War.” They quickly discover it isn’t a game; they’ve triggered the real thing. In the end, they discover that “the only winning move is not to play.”
That’s certainly the case with the West Fork.
As always, these are my opinions on matters of public policy. They are protected by the First Amendment of the United States Constitution and the Anti-SLAPP statute of the Great State of Texas.
Posted by Bob Rehak on 1/26/19
515 Days since Hurricane Harvey