Tag Archives: Addicks Reservoir

The Real Estate Crime of the Century

Over the past 30-40 years, real estate developers in Houston have planned and built entire neighborhoods that were destined to flood.  There are two giant reservoirs located on what used to be the far western edge of the Houston metropolitan area.  These are the Addicks and Barker reservoirs which were built in the 1940’s after severe floods almost wiped out central Houston in 1929 and 1935.  Two miles-long earthen dams on the eastern edge of the reservoirs contain rain water that would otherwise flow into Buffalo Bayou which snakes through some of the priciest real estate in Houston and its suburbs before dumping into the Houston Ship Channel.  The HSC itself was once the easternmost part of the Bayou until it was dredged and channelized to allow massive cargo ships to dock close to downtown Houston – almost 40 miles inland from the Gulf of Mexico.  The map below shows a much smaller Houston and the plan for the Addicks and Barker reservoirs as well as a White Oak reservoir and two canals that were never built.


Most of the time the Addicks and Barker reservoirs are empty and house golf courses, soccer and baseball fields, shooting ranges, hiking trails, model aircraft runways, dog parks and host of other wonderful recreational uses.  Major streets even run through them. But they are designed to flood in a big storm.  When the Army Corps of Engineers designed and built them, the government only bought land behind the dams up to the then-existing 100 year flood plain.  However, if water ever reached the spillway elevation on the dams, it would flood areas far beyond the government owned land.  So, probably because it was cheap and relatively close-in, several developers snapped up the land outside the 100 year flood plain and built neighborhoods, shopping centers and commercial buildings in an area that would flood if water in the reservoirs went above the 100 year flood plain.  These neighborhoods include parts of such high-profile areas as Cinco (make that Sinko) Ranch and Kelliwood.  The map below shows areas that were built in the basin of the Addicks reservoir that will flood at various elevations.  The purple area is government-owned land.  But every area that is colored will flood if the water reaches the spillway.


Red doesn’t know what kjnd of disclosures were given to purchasers, but plenty of homeowners have come forward claiming that they never knew that their homes would flood if the reservoirs filled up.  Red does kind of suspect that might just be the case.  He also suspects that if a prospective home buyer had been told, “By the way, if that there reservoir ever fills up, you’re gonna be under 6 feet of water.  Just thought you’d like to know”, many buyers might just have considered other options.

Then along comes a Hurricane Harvey and the worst possible scenario plays out.  The masters of the dam are faced with a dilemma.  Do we flood more houses and businesses behind the dam – where stuff never should have been built anyway – or do we flood homes and businesses along Buffalo Bayou – where stuff probably should not have been built either?  Hands were tied to some degree as the reservoirs filled up.  Uncontrolled releases downstream were unacceptable and the prospect of the dams failing was just too dire.  The folks below the dams were flooded – but so were the homes built where they never should have been in the first place.

And that folks, is the real estate crime of the century.

More on Dam Problems for Harris County

The Barker and Addicks Reservoirs are reaching historical levels after the recent rains in Harris County.   For the first time ever, the National Weather Service has issued flood warnings for both reservoirs.  The Army Corps of Engineers also released a statement warning residents living behind the reservoir to be ready for flooding.

The water level in the Addicks Reservoir was measured Wednesday night at 101.4 feet and is expected to crest at 103.2 feet, surpassing the previous record for the reservoir of 97.46 feet set in March 1992. The Barker Reservoir was 93.8 feet and expected to crest at 97.7 feet, also exceeding the March 1992 record of 93.6 feet.

Officials say the dams are not expected to reach 100 percent capacity.  However, part of the reservoirs are on private property.  If the water levels rise more than anticipated, area roadways and some subdivisions will be flooded.

Harris County Judge Ed Emmett said officials are considering acquiring sandbags for deployment on “non-governmental land” behind the Addicks and Barker reservoirs due to the potential flooding of homes.

A Big Dam Failure in Houston?

In fall 2009, the U.S. Army Corps of Engineers tagged West Houston's Addicks and Barker dams with an "extremely high risk of catastrophic failure" label. According to the Corps, the 1940s-era dams, which leaked in April 2009, are two of the country's six most dangerous. As a result, the Corps, during an abnormal weather event, might be forced to release more rainwater downstream, which could send Buffalo Bayou out of its banks and flood homes in Memorial and Tanglewood.

With more rain on the way, nervous Houstonians may not even be aware that two aging dams stand between them and catastrophe.  It’s not a new problem.  Check out Steve Jansen’s article in a July 2012 edition of the Houston Press.   As if you didn’t have enough to worry about.

Addicks and Barker have also been weakened due to the natural decline of dams that are made out of a big pile of dirt. According to a 2010 study released by the United States Society on Dams, soil and rocks that have been used in dam construction tend to deform, erode and lose strength over time.

As a result, Houston’s most valuable and proven flood-control mechanisms might not be able to protect the city against a 25-year storm event, says Lawrence Dunbar, a former head of the Army Corps of Engineers’ flood control and reservoir regulation section in Chicago.

“The Corps isn’t quite sure how these voids got formed. Therefore, they’re not sure if you get another big rain and the reservoir fills up again, even if it doesn’t get high as it got before, they’re not sure it can hold and voids won’t form again,” says Dunbar, a licensed professional engineer in Texas since 1983.

In the 1980s, the Corps installed concrete walls inside the earthen part of the dam to discourage leakage. However, the concrete wasn’t installed above or below the culverts, which need replacing in the worst way.

“That’s where they found these voids — under the culverts,” says Dunbar. “What happens when a void forms is, it can basically let water blow through under the culverts or through the dam. When that happens, it’s bad and dam failure is imminent. It’s a big concern,” says Dunbar.