Culvert safety grill causing flooding

This outfall safety grill catches all the small debris, bottles & leafs that passes the screen at the other end. On Monday it was completely blocked & spurting out the top! I cleared it, but two days later it is over 50% blocked again!

When blocked, it backs up so much that Colwell Brook north of the A40 overtops & all the debris get washed over into the adjacent Burwell Drain culvert, which is not screened & is susceptible to blockage - as it did in 2007, causing dozens of homes to flood.

I'm no expert, but it seems to me that an easy solution would be to rotate the grill through 90 degrees to allow more of the small rubbish to pass over the bars. Failing that, a cage with side walls built out from the pipe would provide a greater surface area & be less likely to block.

If you could find the resource to address this problem sometime, we would be grateful.

(The pictures are from today's blockage, which raised the water level upstream by a good nine inches).