After his father's death and his own admission to the Virginia bar in 1917, Flood began a legal practice in Appomattox, Virginia.
World War I
He also took over what remained of the family plantation. During World War I, Flood served from March 29, 1918, until his discharge July 18, 1919, as a private in Company A, Three Hundred and Fifth Engineers, Eightieth Division.
Early political career
Appomattox County voters elected Flood Commonwealth attorney in 1919, a position once held by his elder half-brother Henry D. Flood. He was re-elected multiple times and served until November 8, 1932. Also, upon returning to Virginia, Flood became a member of the unofficial Byrd Organization created by his nephew Harry F. Byrd upon the demise of Sen. Thomas Staples Martin. Joel Flood also served as an assistant to Governor E. Lee Trinkle of Virginia from 1922 to 1926, and as special assistant to the Attorney General of Virginia from April 1, 1928, to July 1, 1932.
Congress
Elected to Congress as a Democrat to fill the vacancy caused by the death of Henry St. George Tucker, he served from November 8, 1932, to March 3, 1933 (in the Seventy-second Congress). The seat was eliminated due to restructuring after the 1930 census. Flood was not a candidate for election to the Seventy-third Congress, but returned to his legal practice and agricultural pursuits. He also served as a delegate to the Democratic National Convention in 1936. He was appointed assistant United States attorney for the Western District of Virginia and served from June 1, 1939, to January 28, 1940. Virginia legislators elected him as a judge of the fifth judicial circuit of Virginia in January 1940, in which capacity he served until his death.
Death and legacy
Joel Flood died in the Richmond Veterans Administration hospital Chesterfield, Virginia on April 27, 1964. He is interred in the Flood Mausoleum, Appomattox Courthouse Square.