Yard catchbasin for school play areas?

[PG35]

I have used 18" dia. csp catch basins with cast iron grates in the past to drain playground area's combined with a cont. swale.

The grates are fiarly lightweight. Since a child could lift the grate it may be a safety issue. I was wondering if there was a typical way of preventing children from removing the grate while keeping the cover removable for maintenance?

Does anyone have an experience with using similar yard catchbasins in play area's?

 

[civilperson]

Weld or bolt grates to frame.