Public Works Operations Crews clean storm sewers intakes all around the city twice a year. During this time, they also are identifying deteriorating intakes that need repairs. With much of the older storm sewer infrastructure, crews are finding sinkholes developing around them. Sinkholes occur because of old construction methods of block and mortar for the walls of intakes. In time, the mortar deteriorates, and the block will fall into the intake, leaving a void in the wall. New materials and methods for constructing storm sewer intakes include pre-cast concrete, cast-in-place concrete, or PVC materials.
In some cases, we prevent sinkholes from causing too much damage by just reconstructing the intake. In many cases, the void in the intake wall allows water to remove the sub-base material from under the street, causing the pavement to fail. When this happens, the crews must not only repair the storm sewer intake but sections of the road adjacent to the intake.
Crews have been working diligently to replace as much of this aging storm sewer infrastructure as possible before winter.