ITD Program: Maintainable Weep Hole Filters

Description of Demonstration:

Michigan DOT, Jet Filter System, and L.S. Engineering teamed with the ITD Working Group to demonstrate Jet Filter’s ability to provide primary drainage to relieve hydrostatic pressure in a box culvert.

Abstract of the published Summary Conclusion by L.S. Engineering, Independent Consultant.

MDOT’s aging twin box culvert originally included 3” weep holes designed with pockets of coarse stone backfill followed by finer granular material. Over time, the weep holes failed, allowing finer backfill material to escape, which created voids in the surrounding soils.  The weep holes were then plugged to prevent further erosion. This resulted in water finding alternative paths through cracks and additional voids as soils passed with the water. Traditional repair of the existing culvert, by excavating, then replacing the coarse aggregate and adding geotextile behind the culvert sidewall as originally designed, would be very intrusive and costly.

Installing Jet Filter System’s innovative technology demonstrated that drainage was restored to the culvert at a significantly lower cost than traditional reparation methods. Also, retrofitting with the Jet Filters saved time, as 52 installations were completed in a day and a half without traffic interruption.   

Maintainability is also an innovative part of the Jet Filter product. The existing weep holes did not have maintainable components. The ability to remove the geotextile housed in the filter cartridge, to inspect and, if needed clean, poses an advantage over the existing design. 

Jet Filter System has provided solutions to both preservation and new earth retaining infrastructures to help extend service life and reduce budget constraints primarily in transportation (box culverts, bridge abutments, many types of retaining walls), as well as marine and flood control markets.


Program Application: Maintainable Weep Hole Filters – ITD Application

Final Report: ITD Final Report – Culvert Maintainable Drain with Appendixes

Additional Daily, Weekly and Quarterly Reports can be found at:

Contact Info:

David Heilman
Jet Filter System, L.L.C.
(616) 405-9418
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