Griffin was tasked with dewatering two (2) large ponds, several thousand feet of utility piping, cofferdams and box structures.


Water was a few feet below existing grade. Griffin was tasked with providing a dry working surface with levels deeper than 16’ bgs. The geology consisted of sand with clayey sand layers. Permitting coordination between several governmental entities was necessary to determine an allowable discharge location.


We addressed the layered geology by installing wellpoints with an 8” casing. We backed filled each casing with filter sand to allow water trapped above the clay layers to travel to each wellpoint bore. Ponds: Griffin installed approximately 1,500LF of wellpoints around each pond and successfully completed drawdown Utilities: Griffin installed over 10,000 LF of header pipe and successfully provided the contractor with a dry working subgrade to complete their pipe installation.

Canal Cofferdam: Griffin installed header pipe inside the cofferdam and added sump pumps to complete drawdown to allow the contractor to install the headwall leading into the bank of the canal. Structures: Griffin installed systems around several structures to allow the contractor to set them in dry working conditions.


Wellpoints were installed with a large-diameter sand casing to address the layered geological conditions and allow draining of the upper sands. The project was successfully completed ontime while the facility continued regular operations. 

The high-watertable, tight working conditions and logistical challenges were overcome by Griffin’s expert engineering and operations teams. The design of the system allowed the lines to be dewatered concurrently, which saved the contractor a significant amount in operational costs.