Do Cattle Grids need maintenance?

Put simply “yes”.

There is no point in spending a serious sum and then neglecting your purchase until it fails to do its job.

Depending on the location your Guru recommends at a minimum an annual clean out.

In an ideal world if you have bought a decent unit the grids can be removed while the work is carried out.

Avoid balancing the grids on end as this can lead to serious injury.

Ensure drainage holes are not blocked

Regret buying a grid which has not been galvanised!

Fish out, carefully, the various amphibians who have made the pit their home (willingly or otherwise)