Can i lower this drain hopper?

[noseall]

It's not a hopper, it's a gulley.

It's a two-parter by the looks of it. That is a removable hopper with a trap below, probably.

 

[noseall]

all.

During last night's monsoon, the patio flooded to three inches deep.

Obviously, the hopper is sod all good for draining that, as it stands.

Can I drop it down closer to ground level?

I've checked today, and it is connected to the main inspection pit on my driveway.
View attachment 305822

For now, drill out that 50mm spigot inlet, or just pull out the hopper. If the whole arrangement was swapped for a shallower bottle gully, then you may increase your chances of setting the whole thing lower.