The Sunbury project, authorized under the Flood Control Act of 1936, was designed and built by the US Army Corps of Engineers. The project provided for the construction of a system of levees and concrete floodwalls with a total length of 26,624 feet. Structures for the disposal of interior drainage consisting of six pumping stations, eight interceptor sewers, and other minor relief outlets. Incidental works consist 3 telemetry gaging stations, 4 aluminum flood barriers, 2 sandbag closure structures, and several ramps to afford access over or through the project.
The flood protection works provides protection on the Susquehanna River 3 feet above the flowline for a flood of 556,000 cubic feet per second and provided protection of 620,000 cfs in 1972 which is about the maximum discharge which the city will be protected against by utilizing the freeboard. Along Shamokin Creek, a freeboard of 3 feet is provided against a discharge of 16,000 cfs occurring when the Susquehanna River is at 556,000 cfs. By utilizing the discharge capacity to the top of the freeboard, Shamokin Creek can discharge about 45 percent more than the design flow with 556,000 cfs in the Susquehanna and can discharge 75 percent more than the design flow during low stages in the Susquehanna River.
Following the May 1946 flood, full protection for Sunbury was started that same year and was completed in 1948 for the Shamokin Creek Section; construction for the upper Susquehanna River section started in 1947 and was completed in 1949; the lower Susquehanna River section was started in 1948 and completed in 1951; the closure structures were completed in 1948; and bank stabilization consisting of stone protection gravel filter blanket, and filling voids from Island Park bridge to the railroad bridge was completed in 1950. Construction cost was 6.6 million dollars.
February 1951, the Flood Protection System was turned over to the City of Sunbury to maintain and operate.
Sunbury’s Project is a federally built project which means the components (levee, wall, stations, etc.) are owned by the federal government but the city of Sunbury signed an agreement to maintain the components in perpetuity.
As of 2016 FEMA has deemed The Sunbury Flood Protection Project a Certified Levee in accordance with flood insurance mapping guideline 44 CFR 65.10
In 1992 City had budgetary and financial problems and had requested the assistance of the Authority in order to resolve these problems. After discussions between the City and the Authority, they reached an understanding that the City would be able to obtain budgetary and financial balance by transferring
the responsibility for the day-to-day operation of the City's flood control system to the Authority and by transferring all of the City's flood control property of any kind to the Authority. It was believed at the time that this transfer would provide quality, cost-effective flood control to the citizens of the City of Sunbury, and that it would better provide for the health, welfare and safety of the persons, property and businesses who are protected by the flood control network.
January 1993 the flood project was formally turned over to the Sunbury Municipal Authority as the Maintaining agency and since that time the Authority has procured over 7.6 Million dollars in grants to rehabilitate and update the project.