I'm a recent high school graduate with some foundational engineering knowledge, and I'm designing a ditch system for a homeowner who asked for:
A ditch that won’t fill with sediment while water travels downhill.
A ditch that blends into the environment and is discreet.
A non-hazardous, low-maintenance design.
The goal is diversion only, but the client also requested soil retention during heavy rain. Water from ~800 ft² of sloped common ground is diverted to a natural ditch beside the lawn that leads to a sewer.
Site details:
The ditch lies on a shallow slope.
Terrain is mostly flat, but the ditch runs downhill at a slight angle.
I’m considering a layered grate/filter design (see attached image).
Here’s the concept draft I drew:

Questions:
Will this design effectively prevent sediment buildup and soil loss?
Are there any materials or configurations you'd recommend to increase durability or reduce maintenance?
How can I ensure the structure won’t clog or pose a hazard to animals?
Any help is greatly appreciated, and if any other context is needed, I'll do my best to provide information. Thanks again!