Residents of Harris County and surrounding areas now have and easy way to assess flood potential near them in near real time. It’s called the Harris County Flood Warning System website. It offers near-real-time information from 100+ gages on major streams and rivers throughout the entire region.
Below, you can see part of the welcome screen, zoomed into the North Houston area. It shows the amount of rainfall at each gage.
Most of north Harris County received less than an inch of rainfall yesterday. However, areas to the west, north, and south received up to three inches. Areas upstream from Kingwood received five to six times more rainfall that the Lake Houston Area.
Rainfall patterns like that can lull people into a false sense of security because flooding originates upstream and works its way down.
Given the severity of yesterday’s storms, several people asked last night and this morning, “What is the potential for flooding?” The Harris County Flood Warning System provides answers. Here’s how to use it for maximum effect.
Customized Alerts from Flood Warning System
First, note that The Flood Warning System allows you to create an account and customize alerts. While not necessary, it helps reduce extraneous information in emergencies, so you only receive messages that affect you.
For instance, the San Jacinto West Fork, Spring Creek and Cypress Creek affect those living in the Humble/Kingwood area. All three converge just west of the US59 bridge. So you could sign up for alerts only from gages in those areas.
Data-Driven Mapping System
Note that the Flood Warning System lets you select several map view options to help you understand conditions near you as well as upstream. For instance, if you click “Watersheds” and “Channel Status,” you can see:
- Which watershed you live in
- The near-real-time status of gages in that area
- Where flood danger or possible flooding exists
Drilling Down to Areas of Interest
From there, you can click on gages of interest. The green squares indicate “no flooding danger.” The yellow triangles mean “potential danger.” Red means “flooding.”
So, clicking on the yellow triangle by Shenandoah in the Spring Creek Watershed lets me investigate what’s happening at that gage. See below.
From this information, I can see that the channel is higher than normal, but still well within its banks. The top of bank (TOB) is at 156.26 feet. But the current water level is only at 154.33 feet. More important, I can see from the graph that the water level has peaked and is trending down.
With all other reporting stations in my watershed showing “green,” I can breath easy. Unless we get major rainfall upstream this afternoon. After all, this creek rose 3.5 feet yesterday after receiving about 2 inches of rain upstream. Today, soils are highly saturated and the creek is only about 2 feet from coming out of its banks. Another two inches of rain could cause flooding. (See forecast at bottom of this post.)
Other Valuable Features
Among other features, Harris County’s Flood Warning System offers:
- Historical data so that you can compare current water level data to past floods that may have threatened your home.
- Rainfall alarms that tell you when particularly heavy downpours have occurred near you that could trigger street or stream flooding.
- Inundation mapping that shows the extent of flooding during flood events.
- Color-coded channel status maps to show you at a glance where streams are flooding
- Links to weather alerts
All in all, Harris County Flood Control District has built a powerful tool with its Flood Warning System. It’s intuitive, uncluttered and easy to use, giving you the information you need, when you need it, where you need it, in the form you need it.
It’s fun to explore all the options. If it rains again this afternoon, use the opportunity to teach your family how to use it.
With the information on this web site, Lake Houston Area residents who flooded during Harvey could have seen the 80,000 cubic feet per second released from Lake Conroe barreling down the West Fork toward them…despite the breakdown in the emergency warning system. They could have evacuated sooner. They could have saved vehicles, valuables, and in some cases even lives.
Everyone should become familiar with the Flood Warning System, learn how to use it and bookmark it. If I were a science teacher in this area, learning how to use this site would become part of my curriculum.
Unsettled Weather Continues Today
Chances of additional heavy rainfall in the Lake Houston Area are lower today than yesterday. However, potential for scattered thunderstorms by early afternoon remains, according to Jeff Lindner, Harris County meteorologist.
Lindner adds, “…given the developing instability and cold air aloft, large hail and gusty winds are possible. NOAA’s Storm Prediction Center (SPC) does have nearly all of the area in a “marginal” risk for severe storms this afternoon with a higher threat to our west across southwest and south central TX.”
It will be hard to predict the exact location of these storms, says Lindner. “We could see some additional very heavy rainfall with the storms this afternoon (1-2 inches) in an hour or less. And while grounds are becoming saturated from all the recent rain, only street flooding is expected.”
“With that said, upper Spring and upper Little Cypress Creeks are elevated and should heavy rains impact NW Harris County, there could be some minor lowland flooding along the headwaters of those channels.”
“Upper level high pressure begins to build into the area Friday and will gain a foothold over the region this weekend into next week. Expect rain chances to taper back to only 10-20%. We can probably cut chances completely by Sunday,” says Lindner.
Posted by Bob Rehak on 5/28/2020
1003 Days since Hurricane Harvey