This story published online Wednesday, Dec. 20 and appeared in print Thursday, Dec. 21.

In development and engineering circles, the dangers were well documented. But as Houston's leaders repeatedly signed off on a relentless building boom, few mentioned them publicly or took them seriously.

In broad strokes, that's how county and city officials approved the construction of 30,000 suburban homes and businesses in Katy and west Houston on the edges of Addicks and Barker reservoirs, inside invisible lakebeds that government and private engineers had long predicted would be inundated in an extreme storm.

More than 9,000 of those structures flooded during Hurricane Harvey, records show.

A large group of homeowners is now suing the U.S. Army Corps of Engineers, which operates the dams. They contend that in allowing the reservoirs to spill into dozens of neighborhoods, the government seized their property without compensation. Many had no idea — until Harvey struck — that their homes were within the reservoirs' footprint, in areas engineers call "flood pools."

"It's crazy that in a flood pool they can grant permission to build houses," says Flavie LaPorte, a petroleum engineer from Venezuela whose family was forced to abandon their Grand Lakes home in the middle of the night.

She and other displaced homeowners want to know: Why were subdivisions built there in the first place?

Photo: Jon Shapley

A Houston Chronicle review of how more than 100 subdivisions were approved shows that flooding spawned by Harvey was predicted for 26 years in obscure local and federal reports that were either ignored or not widely distributed. The record rainfall came from nature, but its impact was multiplied by man.

More answers emerge from three massive planned communities that rose on the Katy Prairie in the 1990s and 2000s behind Barker Dam.

The plans for Cinco Ranch, Kelliwood and Grand Lakes were laid by companies led by key businessmen who played dual roles in the local oversight of the Katy building boom, records show. Yet in their public roles, they did not speak out about the risk of building in flood pools, according to public records and interviews.

Mark Kilkenny's development firm and L.S. "Pat" Brown Jr.'s engineering company both worked on Kelliwood and Cinco Ranch subdivisions — already worth millions in the 1990s — inside the flood pools of Barker Reservoir. As longtime leaders of Houston's planning commission, neither of them publicly raised the risks of reservoir flooding or mentioned "inundation warnings" on subdivision maps that Fort Bend County has required since 1991.

There was no legal requirement for them to do so.

In an interview, Kilkenny said he didn't know about flood pool risks in the 1990s and later considered them to be outside the scope of the planning commission. He and former commission chairs Marvin Katz and Carol Lewis confirm that the commission never discussed reservoir flood risks or the warnings that appear on 80 Fort Bend subdivision plans the group approved and its leaders signed.

"In my 20 years, there really has never been any discussion I can ever remember dealing with the reservoirs with respect to flooding matters," Kilkenny said.

Kilkenny said he and Brown recused themselves when matters involving their own firms came before the planning commission.

Brown retired in 2004 after 20 years on the commission. He is in ill health and was unable to be interviewed.

Development of Grand Lakes, where LaPorte's family lives, began in 1998, southwest of Cinco Ranch and Kelliwood. Much of it was engineered by Costello Inc., which also was hired by Harris County in 1996 to make recommendations on what to do about reservoir flood pool risks that developments such as Grand Lakes would magnify.

The firm's report found that 6,000 properties worth $500 million were at risk upstream from Addicks and Barker dams, but it didn't recommend buyouts or limiting development. At the time the report was published in 2000, Costello Inc. already was working on plans to add 1,500 more homes to Grand Lakes inside the Barker flood pool.

Since 2000, the number of structures inside the flood pools has swelled to 30,000, records show.

Steve Costello founded Costello Inc. with a partner in 1991. He was later elected to the City Council and now is Houston's flood czar. Costello said he didn't recall his firm's study and said he didn't realize until after Harvey that the two reservoir flood pools could swamp Grand Lakes and more than 200 other neighborhoods.

"I don't look back at why," he said. "I look (at) how we move forward and how we address everything ..."

U.S. Rep. Ted Poe, a Republican from Humble who represents the city's suburbs, conducted public hearings for flooded-out families and has studied reservoir pool damage reports. He says for decades, politics and profits got in the way of protecting Houston's homeowners and its dams.

"There appears on the surface to be a conflict of interest, and looking at it now, those homes should never have been permitted to be built in the empty reservoir(s)," Poe said in an interview. "In the past, politics and profit have prevented progress, so we're in this state now, what are we going to do? All of the affected government entities have to have skin in the game."

The mixture of private business interests and politics is unsettling to thousands of displaced homeowners such as LaPorte, who bought her $350,000 home new in 2007 in Grand Lakes.

Like most other homeowners who live upstream from Houston's two dams, LaPorte did not purchase flood insurance because the house was outside the 100-year flood plain. She didn't realize her neighborhood could be swamped by a reservoir — until, in late August, water rose up the driveway in the middle of the night.

For a decade, the comfortable one-story place LaPorte's family chose in a cul-de-sac had seemed safe and roomy enough for her husband and two children, now 18 and 9, and accessible for her elderly parents, too. The family all hunkered down together to wait out Harvey. Her mother had just been released from the hospital and was still using a walker. Everyone was trying to sleep when water began to rise.

In their rush to escape, they saved almost nothing. They're now struggling to rebuild —and to understand why this happened.

"When we came to America, we thought things were different," she said. "... Honesty is part of what you expect from American culture. You never would have thought they were doing this to you."

When Claire James first moved to a brand-new Katy subdivision called Kelliwood Greens in 1989, her neighborhood near Barker Reservoir was still surrounded by rice fields, cattle ranches and country roads.

But in 1991, when developers decided to add a second section to James' subdivision, the proposal set off a discussion behind the scenes between Fort Bend county and private engineers.

By then, government engineers knew the federal government had not bought enough property around Barker even to contain floodwaters that back up behind the dam in a 100-year flood, U.S. Army Corps reports show.

Fort Bend County Engineer Ron Drachenberg, now retired, said the county initially considered trying to block development closest to Barker Dam but worried that developers and landowners would sue for damages. Instead, he said county officials worked with the Army Corps of Engineers and with private engineers at Brown & Gay to craft a warning for the subdivision maps:

"This subdivision is adjacent to Barker Reservoir and is subject to extended controlled inundation under the management of the US Army Corps of Engineers."

NO WARNING: Damaged elementary school was built in a flood pool - and Katy school officials didn't know

Kelliwood developer Jim Miller, however, said he never participated in any discussions about the flood pool — instead, he also relied on advice from Brown & Gay.

Floods in the winter of 1991 and spring of 1992 created the highest flood elevations ever recorded by the Corps of Engineers. A government appraiser quietly began to prepare reports on the costs of buying out flood pool properties, including James' home and subdivisions in Kelliwood and Cinco Ranch. By 1992, the Corps estimated that the flood pool developments in Harris and Fort Bend already established by Miller's firm and its partners were worth about $150 million.

A buyout could have damaged those investments. The companies had spent money on infrastructure and would have been unable to sell homes.

The Corps took no action.

Pat Brown's firm continued to provide engineering services for more than a dozen subdivisions that soon sprouted near Barker in both counties, records show.

During the Kelliwood and Cinco Ranch building boom, Brown also served as vice chair of the Houston planning commission, which approved many more developments in the flood pool. Katz, who served with Brown as chairman, signed dozens of subdivision maps with the inundation warnings in the 1990s; he said he never noticed them.

Houston's two reservoirs are inside city limits, and the flood pools are in its extended planning areas. So planning commission members, such as Brown and later Kilkenny, reviewed and approved others' flood pool subdivisions in both Harris and Fort Bend counties.

In the early 1990s, Brown's firm also worked briefly as a paid consultant for Harris County studying reservoir flooding. After Brown's retirement, his former firm continued to consult for Cinco Ranch municipal utility districts.

Brown was a co-founder and major shareholder during his years on the planning commission but is no longer part of Brown & Gay, according to documents and the firm's spokesman. Brown & Gay representatives did not respond to requests for additional comment about the firm's role in housing developments in the flood pool.

Neither Houston nor Harris County ever adopted any flood pool rules or disclosure requirements.

Harris County Commissioner Steve Radack told the Chronicle he didn't think warnings were necessary for properties in his county. He says flood pool risks have long been discussed in community meetings and that he gave speeches about them.

Larry Dunbar, a lawyer and an engineer who is involved in flood pool litigation, questions why for decades both Harris County and Houston relied on insiders with an "essential bias" as consultants and as city decision-makers.

"They obviously knew about it," he said. "Theoretically, the first question is, 'Should you be developing a subdivision inside a reservoir?' I don't know if the city or the county even had that discussion — if they had the discussion, they chose not to do anything."

James said she is disturbed by the idea that planning commissioners involved as businessmen in developing her subdivision never discussed reservoir risks.

"Why would a guy who was on the planning commission have pushed for a (buffer zone)?" she asked, rhetorically. "It would have cost him money, and the stigma of a flood zone would have killed sales there as well as in neighboring areas, so he wasn't going to do it."

During Harvey, James waded out of her house through hip-deep water to escape with her husband, her neighbors and 20 dogs inside a military-style troop-transport truck. James' house was paid for, and the couple planned to retire there. Now they're renting an apartment and trying to decide whether to take out another mortgage to reinvest in an area that the reservoir could claim again.

"Now they're telling me I live in the reservoir — but in all the years I've lived here, no one ever told me," she said. "You fill my house up with water and then you tell me I'm living in the reservoir?"

Photo: Craig Moseley/Houston Chronicle Photo: Melissa Phillip/Houston Chronicle Photo: Jon Shapley/Houston Chronicle Photo: Jon Shapley/Houston Chronicle Photo: Melissa Phillip/Houston Chronicle Photo: Melissa Phillip/Houston Chronicle Photo: Jon Shapley/Houston Chronicle Photo: Jon Shapley/Houston Chronicle Photo: Melissa Phillip/Houston Chronicle Photo: Melissa Phillip/Houston Chronicle Photo: City Of Houston

In the 1990s, the building boom west of Barker Reservoir accelerated under the leadership of Houston Mayor Bob Lanier, a multimillionaire developer-turned-politician. Lanier, along with other builders, donated land to speed the construction of the Grand Parkway. As mayor, he also moved money intended for a monorail to help build the Westpark Tollway. Both roads made the former rice farms and ranches attractive to commuters.

The area known as Cinco Ranch soon became one of the nation's fastest-growing developments. As a developer, Kilkenny's firm was involved in Kelliwood and Cinco Ranch subdivision deals. On behalf of Wheatstone Development, he personally signed a subdivision map for the Kelliwood Pointe subdivision with the inundation warning in 1994.

MUDs: What bond investors weren't told about a threat facing Cinco Ranch

Lanier, who's now deceased, in 1997 appointed Kilkenny to the Houston planning commission. As a commissioner, Kilkenny voted to approve many more subdivisions with reservoir warnings in the Cinco Ranch area, though he said his firm didn't own land there at the time of those votes. Fort Bend officials say their warnings generated controversy among West Houston developers. Kilkenny said he never noticed.

"I don't remember any big controversy over that or any argument over why or why not to put it on" the maps, Kilkenny said. "I can tell you that there were never any discussions at the planning commission."

Kilkenny said he first became aware of the potential dangers of the reservoir flood pools in 2009, when the Corps of Engineers announced that it had rated Houston's earthen dams as "extremely high risk" — in part because of all the homes and businesses around them. A report issued the same year warned that private properties upstream from the dams could be flooded for as long as 45-49 days if it rained long enough and if the floodgates were closed to protect Houston.

Kilkenny served as planning commission vice chairman from 2004-2010 and as chairman from 2010-2016. During those years, the commission didn't discuss reservoir flood pool risks when it approved plans for an Alzheimer's home, a nonprofit shelter for the families of the terminally ill and for Kelliwood Park subdivision, all near the boundaries of Barker Reservoir, according to Kilkenny and commission minutes.

Photo: Jon Shapley

All were approved without any discussion, records show. Harris and Fort Bend county representatives attended those meetings and also didn't speak up.

The threat of the flood pools seemed hypothetical and outside the planning commission's scope until 50 inches of rain fell in a few days, Kilkenny said.

During Harvey, water spilled out of Barker Reservoir and consumed the streets of the surrounding subdivisions. The flood pool flowed through Creech Elementary School and entered homes inside Kelliwood Greens, Kelliwood Park, Cinco Ranch and Grand Lakes. It lingered for days.

The water got so deep that, after the rain finally stopped, Fernando Roca drove a Jet Ski more than a mile down roads that looked like part of a lake to reach his home. Inside, the floodwaters had risen nearly a foot, damaging built-in bookshelves, the custom fireplace and a central stairway — details that had attracted Roca and his wife to buy their home new in March 2008.

The Rocas' home had rapidly risen in assessed value, to $553,000 by 2016. They have no idea what it's worth now.

Fernando and his wife, Melissa, are involved in the lawsuit against the Corps of Engineers for using their property to store reservoir water. But the Rocas also want answers from government officials and developers about why there was no disclosure of flood-pool risks in the huge stockpile of title insurance, mortgage papers and legal documents that Melissa managed to save.

Roca, who has an MBA, and his wife and daughter are now bunking with his parents. After a recent family dinner, they stayed at the table to pore through papers that they received at closing. Their fat file contains no reference to the Kelliwood Park subdivision's warning about "extended controlled inundation." Roca first saw that warning when a Chronicle reporter met him inside his flood-damaged home and showed him the subdivision map on a Fort Bend County website.

Someone should have spoken up sooner, he says.

Houston's earthen dams were erected to protect downtown Houston from the kind of catastrophe that wrecked the city during the Great Flood of 1935. Back in the 1940s, it didn't matter if flood pools formed west of the dam across a vast Katy prairie filled with rice farms that attracted huge flocks of snow geese.

But most of the time, the reservoir lake beds are deceptively dry — city and county parks inside the federal lands today offer trails, soccer fields, baseball stadiums and even a zoo.

For three decades, civil engineers working for developers, for counties and for the Corps of Engineers have carefully calculated the size and shapes of the flood pools — the ones that would form in a 100-year flood as well as the largest or "maximum" flood pools. They produced maps based on factors such as the height of the dams, the elevation of surrounding subdivisions, estimated rainfall and the density of concrete and rooftops.

But flood pool maps are hard to find. One version appears in green on the wall inside the city planning commission office. Others appear in reports published by the Corps in 2009 and by Costello Inc. in 2000.

The way forward County commissioners, lawyers, flooded-out homeowners, lawmakers and businessmen have floated ideas that could alert property owners to the potential dangers of the flood pools in neighborhoods upstream of Addicks and Barker dams and protect dams from encroaching development. Here are some of them: — Consider buyouts Federal lawsuits seek to force the U.S. Army Corps of Engineers to compensate residents flooded out during Hurricane Harvey. Some have proposed using settlement money or federal aid to buy out $4 billion of structures in the most vulnerable areas. — Change state law to require additional disclosures to buyers This could be done when property changes hands inside the "maximum flood pools." Providing boundaries and locations of properties that engineers describe as vulnerable to the largest potential reservoir floods would help alert investors to purchase federal flood insurance and to better evaluate risks. — Improve vetting of new development anywhere in the flood pool Currently only Fort Bend requires notification of flood pools on obscure subdivision maps. Although Houston's reservoir pool areas are mostly developed, counties and the city of Houston planning commission, which review development, could immediately require additional notifications or set new rules. — Alert the public to reservoir-related risks and the need for potential evacuations Place sirens or warning signs in public parks inside both reservoirs; improve reverse 911 or develop an app to better contact residents before life-threatening flooding occurs; post detailed maps of flood pools on government websites.

Steve Costello began his career as a civilian employee of the U.S. Army Corps of Engineers in Galveston. His job involved helping draw federal flood plain maps. But he says then or later as a private engineer, he never calculated the size of the maximum flood pool for Houston's two reservoirs prior to Hurricane Harvey and didn't realize those flood pools could affect hundreds of neighborhoods — including Grand Lakes.

At least 20 sections of that subdivision and three of its municipal utility districts are labeled as inside the Barker "inundation" zone, according to Fort Bend County maps.

In Grand Lakes and other subdivisions, more than 4,000 homes and businesses were damaged near Barker's Reservoir and more than 5,000 near Addicks, according to a Chronicle analysis of data provided by Harris and Fort Bend counties.

In an interview, Costello said he didn't know that Fort Bend County required inundation warnings on subdivision maps, even though his firm did include them for Grand Lakes.

"Obviously there were people in my office that might have known about it," he said. "I'm not sure about that, but I'm assuming they did."

Costello was president and treasurer of Costello Inc. during the years that Grand Lakes was developed, state records show. He said he worked on many other projects and on municipal utility districts but was not personally involved in engineering the subdivisions or MUDs his firm established for Grand Lakes.

Records show that MUDs within the flood pool portion of Grand Lakes generated consulting work for his firm for more than a decade. Costello Inc. was listed as consulting engineer for the Grand Lakes' MUDs and its water control district, which issued more than $71 million in bonds from 1999-2014.

Photo: File

Costello was elected to the City Council in 2009, having campaigned as an infrastructure expert. That same year, the Corps of Engineers declared Houston's dams to be among the nation's most dangerous because of their deteriorating condition and encroaching development.

Costello said he didn't read the Corps' report or raise the topic of reservoir flood pools in his years as a councilman from 2010-2015.

Jim Blackburn, an environmental lawyer and Rice professor, has authored papers on post-Harvey solutions and worked on lawsuits related to Houston flooding and its dams for decades. Blackburn said he finds Costello's denials of knowledge about reservoir development dangers "hard to believe."

Blackburn said Costello and other engineers involved in flood pool developments should consider whether they abandoned their duties under state administrative code to "protect the health, safety, property and welfare of the public."

"I think it's reflective of a cavalier attitude of engineers about a lot of these issues and I think that's one of the issues that has to change in our community," Blackburn said. "... Our engineers have to have a much stronger sense of their duty to the public, and if he doesn't remember, then shame on him."

Costello's business interests have given him expertise in the areas affected by Harvey. But they meant he had to step out of the room more often than any other councilman. In his five years on City Council, Costello recused himself from more than 60 matters involving his firm, including city flood-control contracts and reviews of municipal utility district deals spread across the region, records show.

Costello said he sold his share of the firm in 2015 when he ran for mayor. He lost that race, but he was appointed flood czar by Mayor Sylvester Turner. He's now paid a $160,000 city salary. Figuring out how to address flood pool risks is part of his job.

He emphasizes that the city shares the duty to regulate the flood pools with the counties. He calls it "outrageous" that Harris County Judge Ed Emmett has criticized the city of Houston for failing to do enough to control reservoir development and protect its dams. In interviews, Emmett, County Commissioner Jack Cagle and Fort Bend County Commissioner Andy Meyers have called for buyouts and for improved disclosure for flood pool residents — either through state law changes, more complete notes on subdivision maps or even sirens and signs in the reservoir parks.

Costello didn't offer specific ideas about keeping the reservoir residents informed.

"There's always room for improving communication in anything that we do," he said. "So I would suggest as an engineer we could always do a better job of communicating with the public."

Staff writers John Harden, James Drew and Mihir Zaveri contributed to this report.

About our investigation: "Developing Storm"

Hurricane Harvey was the most destructive storm in Houston's history. The late-August storm dumped up to 60 inches of rain on southeast Texas, but the resulting damage was multiplied by actions taken ­– and not taken – during the past 50 years. Our seven-part series explains why the storm's damage was both a natural and man-made disaster.

Lise Olsen, deputy investigations editor and senior investigative reporter, joined the Chronicle in 2003. She has more than 20 years' experience specializing primarily in crime, corruption, worker safety and human rights. Her investigation of unsolved Texas serial murders was made into a 2017 documentary series called "The Eleven." She has been named Texas AP Managing Editors' Star Reporter of the Year three times. Contact her at lise.olsen@chron.com. Follow her on Twitter at @chrondigger.

Multimedia by Houston Chronicle staff

Graphics by John D. Harden

Audience engagement by Rachael Gleason

Design by Jordan Rubio

Get engaged

— Where do we go from here? Seven Houston-area leaders discussed flooding causes and solutions at a Greater Houston After Harvey forum hosted by the Houston Chronicle in early December. Watch Wednesday night's keynote address by Jim Blackburn, co-director of Rice University's Severe Storm Prediction, Education and Evacuation from Disasters (SSPEED) Center. Read his thoughts on living around water.

— Sign up for our Facebook community to share your Harvey story, engage with other community members and ask our reporters questions.

— Join the discussion on Twitter: #HoustonAfterHarvey.

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