A stranded motorist escapes floodwaters on Interstate 225 after Hurricane Harvey inundated the Texas Gulf coast with rain causing mass flooding, in Houston, Texas, U.S. August 27, 2017.  REUTERS/Nick Oxford

A stranded motorist escapes floodwaters on Interstate 225 after Hurricane Harvey inundated the Texas Gulf coast with rain causing mass flooding, in Houston, Texas, U.S. August 27, 2017. REUTERS/Nick Oxford

 The downtown skyline is reflected in flood water in Buffalo Bayou Park after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 27, 2017.  REUTERS/Nick Oxford

The downtown skyline is reflected in flood water in Buffalo Bayou Park after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 27, 2017. REUTERS/Nick Oxford

 Irving Lebleu helps Keshia Walker push her car out of a flooded intersection after Hurricane Harvey made landfall on the Texas Gulf coast, in Houston, Texas, U.S. August 26, 2017.  REUTERS/Nick Oxford

Irving Lebleu helps Keshia Walker push her car out of a flooded intersection after Hurricane Harvey made landfall on the Texas Gulf coast, in Houston, Texas, U.S. August 26, 2017. REUTERS/Nick Oxford

 A man navigates through floodwater after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 28, 2017.  REUTERS/Nick Oxford

A man navigates through floodwater after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 28, 2017. REUTERS/Nick Oxford

 An abandoned vehicle is covered by flood waters on Interstate 610 after Hurricane Harvey inundated the Texas Gulf coast with rain, in Houston, Texas, U.S. August 27, 2017.  REUTERS/Nick Oxford

An abandoned vehicle is covered by flood waters on Interstate 610 after Hurricane Harvey inundated the Texas Gulf coast with rain, in Houston, Texas, U.S. August 27, 2017. REUTERS/Nick Oxford

 Residents wade through floodwater after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 28, 2017.  REUTERS/Nick Oxford

Residents wade through floodwater after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 28, 2017. REUTERS/Nick Oxford

 A man carries his belongings through flood waters after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 28, 2017.  REUTERS/Nick Oxford

A man carries his belongings through flood waters after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 28, 2017. REUTERS/Nick Oxford

 Evacuees Rickey Manuel (L) and Marjory Manuel (C) exit a U.S. Coast Guard helicopter that rescued them after Hurricane Harvey inundated the Texas Gulf coast with rain and flooded their home, in Houston, Texas, U.S. August 27, 2017.  REUTERS/Nick Oxf

Evacuees Rickey Manuel (L) and Marjory Manuel (C) exit a U.S. Coast Guard helicopter that rescued them after Hurricane Harvey inundated the Texas Gulf coast with rain and flooded their home, in Houston, Texas, U.S. August 27, 2017. REUTERS/Nick Oxford

 Evacuees are transported to the George R. Brown Convention Center after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 27, 2017.  REUTERS/Nick Oxford

Evacuees are transported to the George R. Brown Convention Center after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 27, 2017. REUTERS/Nick Oxford

 Evacuees are unloaded from the back of an open bed truck at the George R. Brown Convention Center after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 27, 2017.  REUTERS/Nick Oxf

Evacuees are unloaded from the back of an open bed truck at the George R. Brown Convention Center after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 27, 2017. REUTERS/Nick Oxford

 Volunteers with The American Red Cross register evacuees at the George R. Brown Convention Center after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 28, 2017.  REUTERS/Nick Oxf

Volunteers with The American Red Cross register evacuees at the George R. Brown Convention Center after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 28, 2017. REUTERS/Nick Oxford

 Evacuees get some rest in the warehouse at Gallery Furniture which opened its doors to residents needing shelter, in Houston, Texas, U.S. August 29, 2017.  REUTERS/Nick Oxford

Evacuees get some rest in the warehouse at Gallery Furniture which opened its doors to residents needing shelter, in Houston, Texas, U.S. August 29, 2017. REUTERS/Nick Oxford

 A stranded motorist escapes floodwaters on Interstate 225 after Hurricane Harvey inundated the Texas Gulf coast with rain causing mass flooding, in Houston, Texas, U.S. August 27, 2017.  REUTERS/Nick Oxford
 The downtown skyline is reflected in flood water in Buffalo Bayou Park after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 27, 2017.  REUTERS/Nick Oxford
 Irving Lebleu helps Keshia Walker push her car out of a flooded intersection after Hurricane Harvey made landfall on the Texas Gulf coast, in Houston, Texas, U.S. August 26, 2017.  REUTERS/Nick Oxford
 A man navigates through floodwater after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 28, 2017.  REUTERS/Nick Oxford
 An abandoned vehicle is covered by flood waters on Interstate 610 after Hurricane Harvey inundated the Texas Gulf coast with rain, in Houston, Texas, U.S. August 27, 2017.  REUTERS/Nick Oxford
 Residents wade through floodwater after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 28, 2017.  REUTERS/Nick Oxford
 A man carries his belongings through flood waters after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 28, 2017.  REUTERS/Nick Oxford
 Evacuees Rickey Manuel (L) and Marjory Manuel (C) exit a U.S. Coast Guard helicopter that rescued them after Hurricane Harvey inundated the Texas Gulf coast with rain and flooded their home, in Houston, Texas, U.S. August 27, 2017.  REUTERS/Nick Oxf
 Evacuees are transported to the George R. Brown Convention Center after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 27, 2017.  REUTERS/Nick Oxford
 Evacuees are unloaded from the back of an open bed truck at the George R. Brown Convention Center after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 27, 2017.  REUTERS/Nick Oxf
 Volunteers with The American Red Cross register evacuees at the George R. Brown Convention Center after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 28, 2017.  REUTERS/Nick Oxf
 Evacuees get some rest in the warehouse at Gallery Furniture which opened its doors to residents needing shelter, in Houston, Texas, U.S. August 29, 2017.  REUTERS/Nick Oxford

A stranded motorist escapes floodwaters on Interstate 225 after Hurricane Harvey inundated the Texas Gulf coast with rain causing mass flooding, in Houston, Texas, U.S. August 27, 2017. REUTERS/Nick Oxford

The downtown skyline is reflected in flood water in Buffalo Bayou Park after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 27, 2017. REUTERS/Nick Oxford

Irving Lebleu helps Keshia Walker push her car out of a flooded intersection after Hurricane Harvey made landfall on the Texas Gulf coast, in Houston, Texas, U.S. August 26, 2017. REUTERS/Nick Oxford

A man navigates through floodwater after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 28, 2017. REUTERS/Nick Oxford

An abandoned vehicle is covered by flood waters on Interstate 610 after Hurricane Harvey inundated the Texas Gulf coast with rain, in Houston, Texas, U.S. August 27, 2017. REUTERS/Nick Oxford

Residents wade through floodwater after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 28, 2017. REUTERS/Nick Oxford

A man carries his belongings through flood waters after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 28, 2017. REUTERS/Nick Oxford

Evacuees Rickey Manuel (L) and Marjory Manuel (C) exit a U.S. Coast Guard helicopter that rescued them after Hurricane Harvey inundated the Texas Gulf coast with rain and flooded their home, in Houston, Texas, U.S. August 27, 2017. REUTERS/Nick Oxford

Evacuees are transported to the George R. Brown Convention Center after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 27, 2017. REUTERS/Nick Oxford

Evacuees are unloaded from the back of an open bed truck at the George R. Brown Convention Center after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 27, 2017. REUTERS/Nick Oxford

Volunteers with The American Red Cross register evacuees at the George R. Brown Convention Center after Hurricane Harvey inundated the Texas Gulf coast with rain causing widespread flooding, in Houston, Texas, U.S. August 28, 2017. REUTERS/Nick Oxford

Evacuees get some rest in the warehouse at Gallery Furniture which opened its doors to residents needing shelter, in Houston, Texas, U.S. August 29, 2017. REUTERS/Nick Oxford

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