Hollis R. Williams, 71, who was deputy administrator for watersheds of the Soil Conservation Service in the Department of Agriculture for 13 years before retiring in 1972, died Wednesday at Arlington Hospital after a heart attack. He was a resident of Arlington.

During his years with the SCS, he was a leader in government flood prevention and soil conservation programs. The service has worked with local authorities to protect millions of upland acres by building dams and taking other conservation measures to slow the runoff of storm waters. These measures help prevent flooding along major rivers.

In 1965, Mr. Williams received Agriculture's highest honor, the Distinguished Service Honor Award, "for distinguished administration and technical achievement in the SCS program of assistance to local government organizations on small watershed projects."

Mr. Williams began his government career in the South in 1934 as a clerk with the Interior Department's old Soil Erosion Service, a predecessor of the Soil Conservation Service. He became the SCS conservationist for Arkansas and, in 1957, the regional field representative for the Southeast states. He was transferred to Washington as a deputy administrator of the SCS in 1959.

He was a fellow of the Soil Conservation Society of America and a member of the National Association of Conservation Districts. He also was a member of the administrative board of the Arlington Forest United Methodist Church.

Mr. Williams, who was born in Mayflower, Ark., was a 1932 graduate of Arkansas State Teachers College and a 1939 graduate of the North Texas School of Law.

Survivors include his wife, Virginia A., of Arlington; a son, Hollis R. Jr., of Lake Charles, La.; a sister, Coy Burgin of Long Beach, Calif.; two brothers, Dennis R. of Berkeley, Calif., and Troy T. of Little Rock, Ark., and two grandchildren.