Tenth Anniversary of Memorial Day Flood

5/25/25 – Jeff Lindner, Harris County’s meteorologist, reminds us that today marks 10 years since the Memorial Day flood of 2015.

Slow Moving Line of Non-Tropical Thunderstorms

In 2015, we had weeks of on and off heavy rainfall over the region. Then a slow moving line of heavy thunderstorms during the evening hours of May 25th resulted in significant flash flooding over the central and southern portions of the Houston metro area.

Rainfall totals of 8.0-10.0 inches were recorded in a 3 to 6 hour period.
Eleven inches fell on Brays Bayou at Beltway 8 in just over 6 hours.
In northeast Fort Bend County the total reached 11.88 inches.
On average, across Harris County 5.3 inches of rain fell equaling 162 billion gallons of water in less than a 12 hour period.
The resulting flooding along Brays and Buffalo Bayous produced significant structural damage.
Brays Bayou water levels rose to their highest levels since September 1983.
An estimated 6,335 homes were flooded, 3,540 multi-family units, and 92 commercial buildings.

At the time, the Memorial Day flood had the second largest number of flooded structures in Harris County only behind Tropical Storm Allison in 2001 (73,000 flooded homes).

The map below shows where the heaviest rain fell. At the time, the area with the heaviest rainfall exceeded a 100-year event.

Even by Atlas 14 standards, which came in after Harvey, some of those totals would equal a hundred-year (1% annual chance) storm.

To see Lindner’s full report on the storm, click here.

Lake Houston Area Spared Worst of Storm

If those in the Lake Houston Area don’t remember the storm, that’s because we only got about 5.5″ of rainfall from it at US59 and the West Fork. 3.4 inches of that fell in the two-hour period between 9 and 11 PM. That’s intense, but not record setting.

Crosstown, it was twice as worse. Brays Bayou at Beltway 8 West received more than 11 inches. 6.4″ fell in a two hour period between 10 PM and Midnight.

And Buffalo Bayou at Beltway 8 West received 10.68 inches. Almost 7″ of that fell in the same two-hour period.

To see other totals, explore the Harris County Flood Warning System’s Historical Rainfall feature.

Start of Period of Catastrophic Flooding

Lindner added, “Little did any of us know at the time, but the Memorial Day flooding would mark the start of an onslaught of catastrophic floods for southeast Texas and the metro Houston area.”

To learn more about those subsequent events. see the Reports page of this website and click the Major Storms tab. They include a Tax Day and second Memorial Day storm in 2016; Hurricane Harvey in 2017; Tropical Storm Imelda in 2019; and Tropical Storm Beta in 2020.

Prepare Now; Hurricane Season Starts in One Week

This should serve as a reminder that hurricane season starts one week from today. Often, one of the first things to go in a major storm is electricity because of trees falling on power lines. I remember losing power for 22 days during Hurricane Ike.

Subsequently, I purchased several power bricks to recharge cell phones during a prolonged outage. One even has solar panels to recharge it and has AC outlets to run lights for reading at night. I don’t use them often but consider them a great investment.

The last time I purchased a new vehicle, I made sure that it had satellite networking/communication capabilities built into the electronics – another great investment. It came in very handy when even cell towers lost power for more than a week after Beryl last year.

See my Links page for more preparedness tips.

Posted by Bob Rehak on 5/25/25

2826 Days since Hurricane Harvey