For some time this place has needed a few drains.
I have improved it over the years, with all the recent rains I have made a few open drains to check the flow etc etc.
Saw a few Utubes on french drains. They ALL say the same thing

i have  a trenching spade :-). Made specifically for digging a trench. .
Dig a trench, line it with geotextile fabric, use excess fabric up the sides and more than enough to fold over the top when it is finished.
Put 30 mm of gravel at the base of the drain on top of the geotex, lay  a slotted 65 mm drain in there, fill it all with more gravel, Fold the excess geotex over the top of the gravel channel, put grass sods over that.
hhmmm, trench has to be pretty deep. 150 mm?
That all does the water underneath.
For surface water use a Uni-Pit With Flat Grate and drain it into the gravel channel below.
I need a few of those.

Bigger job than I thought.

I have used something similar to this before, where I needed to divert a lot of water quickly (overland flows) so it didn't go under the house:

https://www.bunnings.com.au/everhard-3m-easydrain-polymer-grate-and-prejoined-channel_p4770175?store=8087&gad_source=1&gclid=CjwKCAiAtt2tBhBDEiwALZuhAMtfCIwSwNn8dbrpET0uCE1__58QspHM7KNl-lwRXn-hAWhSqcGlWBoC0GgQAvD_BwE&gclsrc=aw.ds

I assume your gravel trench is to help a boggy patch dry out quickly?

I always drill big holes into the bottom of my down pipes as well so that if ever the pipes get clogged with leaves or there is too much water because of downpours, the water has somewhere to go other than my soffits.

You mean the top?

freediver wrote on Jan 30^th, 2024 at 4:24pm:

You mean the top?

No, I mean the bottom of the downpipes.

So the water doesn’t reach the top of the drain pipe.