The Sunbury Flood Wall was proposed after the disastrous flood that occurred in March of 1936. The City and residents suffered over 4 million dollars in damage.
Construction of the flood system began in May of 1946 by the War Department, later changed to the Department of the Army, and was completed in 1951 at a cost of 6.6 million dollars.
The existing flood control system of that protects 147 acres of the City of Sunbury is a combination of 2.4 miles of flood wall, 2.6 miles of levees and several pumps monitoring stations. This system has evolved and been improved over the course of 60 years to protect the City from flooding.
The largest component of the Sunbury protection flood protection system is the flood wall. There are two basic flood wall types, the T wall that averages 19’ tall and ‘I’ wall which average 12’ tall. Currently there are 6 openings in the current flood control system. These openings have been tested several times and have proven to be reliable against event floods.
The Flood Control system is a complex network of pump stations, drainage structures, interceptor storm drains, sluice gates, flap gates, levees, floodwall, closure structures and early warning systems that work together to provide protection from the raging waters of Shamokin Creek and the Susquehanna River.
Specifically, the flood system is comprised of:
- 2.4 miles of concrete floodwall
- 2.6 miles of earthen levee
- 6 pumping stations
- 8 interceptor sewers
- 11 drainage structures
- 7 closure structures
- 61 flap gates
- 31 sluice gates
Since the 1800's, the Susquehanna River has experienced a significant flood event on the average of once every 20 years. The Sunbury Flood Wall has protected Sunbury from over 15 high water events since it was completed in 1951.
In 1972, flood waters from Hurricane Agnes crested at 35.8 feet at Sunbury, two feet higher than the crest in 1936. The wall held back the water and residents showed their gratitude in messages left on the wall.