Top of grate catch basin filter

DETAILED DESCRIPTION Our invention is a removable catch basin filter for a storm sewer catch basin which is equipped with a removable top inlet grate.
The filter is essentially located on top of the catch basin grate.
The filter is typically composed of a porous geo textile fabric which covers the grate inlet.
Pollutant solids are held back by the fabric while the water flows into catch basin through the grate.
The filter enwraps the grate thereby preventing storm water from entering the grate without passing through the filter.
The filter includes a centrally located by pass opening.
A wall water barrier protects the opening and, during low flows, forces the water to enter the grate only through the surrounding filtration fabric.
The wall is limited in height.
During high water conditions the water flows over this low wall and into the catch basin.
This wall is made of a compressible material such as foam rubber and easily flattens with traffic weight.
The filter therefore poses little threat to traffic safety.
The wall springs the by pass opening top back to its former position when it is no longer weighed down.