Simon W. Freese, civil engineer, was born at Blossom, Texas, on December 4, 1900, son of Wilke Harm and Leonora Novella (Hancock) Freese. His father was a building contractor. Freese finished high school at Paris, Texas, in 1917, attended Southern Methodist University two years, and earned a bachelor of science degree in civil engineering in 1921 from Massachusetts Institute of Technology. In 1923–24 he pursued postgraduate studies in bacteriology and chemistry at Cambridge University in England.
Freese joined the consulting engineering firm of John B. Hawley at Fort Worth in 1922. Hawley made Freese a partner in 1927. In 1930 Marvin C. Nichols joined the firm, which was called Hawley, Freese, and Nichols until Hawley retired in 1937. Under the name of the successor organization, Freese and Nichols, the firm incorporated in 1977 with senior partner Freese as chairman of the board.
Freese was a specialist in hydraulic and sanitary, or "environmental," engineering, as the speciality was dubbed during the 1960s. He conceived and designed approximately 100 municipal water and sewerage systems for Texas cities, including Fort Worth, Dallas, Houston, Beaumont, Austin, San Antonio, Corpus Christi, Lubbock, and Amarillo. He was responsible for his firm's involvement in more than 200 dam and reservoir projects, including lakes Fort Phantom Hill, Mackenzie, J. B. Thomas, E. V. Spence, Cedar Creek, Greenbelt, Hubbard Creek, White River, Conroe, and Richland Creek.
After floods killed thirty-seven people at Fort Worth in April 1922, Freese and Hawley recommended construction of lakes Eagle Mountain and Bridgeport. Freese designed both dams. When completed (Bridgeport in December 1931 and Eagle Mountain in October 1932), the two lakes were the first large dual-purpose reservoirs in the United States to provide separate reservoir capacities for flood control and water supply.
Freese helped pioneer the modern activated sludge process in American sewage-treatment plant design. At Cambridge in 1923–24 he studied the early English activated sludge plants, the most advanced in the world at that time. He incorporated the process into his design for San Antonio's first sewage-treatment plant, built in 1929–30. The San Antonio plant, which treated thirty million gallons a day, was one of the earliest activated sludge plants in the United States and was among the largest constructed before 1931.
The firm was active during World War II as architect-engineers of twenty-one major installations for the army, air force, and navy, including camps Hulen, Barkeley, Swift, and Fannin. In 1943 Freese entered the United States Army and was on Gen. Dwight D. Eisenhower's staff, Supreme Headquarters, Allied Expeditionary Force. He was economics officer for the military government and public works administrator in Germany and the occupied territories. He was the United States member of the Quadripartite Committee for Central German Administrative Agencies and aided in setting policy for a central German government under Allied control. He was discharged in March 1946 with the rank of lieutenant colonel.
Between 1946 and 1949 Freese helped establish the Colorado River Municipal Water District, the state's first multi-city water district. The project introduced the concept of joint water-supply facilities to serve a group of cities. He chaired the Texas section of the American Society of Civil Engineers' 1951 Committee on State Water Policy, which wrote the state's first comprehensive water policy. Freese was principal author of A Water Policy for Texans (1952), precursor to the Texas Water Plan of 1968.
He was a member of the American Society of Civil Engineers, American Water Works Association, National Society of Professional Engineers, and Texas Water Conservation Association. He published professional papers on sewerage and water treatment. In 1975 the American Society of Civil Engineers established the national Simon W. Freese Environmental Engineering Award and Lecture. Texas Wesleyan University awarded Freese an honorary doctor of science degree in 1980. In 1981 he received the Texas Section, ASCE, Award of Honor. In 1984 the parent society made him an Honorary Member, ASCE's highest national honor. He was cited for "exceptional service as an engineer and a citizen of the state of Texas, and for his major role in enabling Texas to meet water resource needs." In May 1990 the Colorado River Municipal Water District dedicated the dam impounding the O. H. Ivie Reservoir near Ballinger as S. W. Freese Dam.
Freese was a Methodist and a Democrat. He married Eunice Elizabeth Brooks in Dallas on June 30, 1927. They had three children. Mrs. Freese died in Fort Worth on November 28, 1985. Freese died on July 27, 1990, in Fort Worth. He was active in engineering until a few months before his death and participated in writing a centennial history of Freese and Nichols, Incorporated.