When you have a construction company create drains and install grates on your property, you may envision all runoff seamlessly flowing into the drain and away from your house and landscaping. It can be very annoying, then, to find the drains occasionally covered with relatively small pieces of leaves that prevent proper drainage.
This is something that happens to all grates that are properly installed, so it's not a matter of finding a different grate. When you understand why the grate openings are so narrow, you'll understand why the construction company used them.
Preventing Leaves From Entering the Drain
Water needs to flow freely through a drain in order to prevent flooding on your property. That means that leaves and other debris should not get into the drain, where they can form clogs. To prevent that, the grate needs to have openings small enough to trap leaves, rather than let them through. When there are a lot of leaves flowing along with the runoff, that means those leaves can end up sitting on top of the grate.
Asking the construction company to create grates with bigger openings isn't a good idea. If you allow bits of leaves to enter the drain, sooner or later those bits could cause a problem. It's much easier to clean leaves off the top of the grate than it is to have a clogged drain cleared out.
Preventing Trip Hazards
The construction company installing the grates knows that the openings, if too big, could present a trip hazard. It's bad enough to think of the high heels that get caught in the small openings, but with larger openings, people could genuinely trip and fall. The construction company wants you to be happy with their work, but they also need everyone walking past the grate to remain safe.
The Width Is Often Matched to the Purpose
There are grates with differently sized openings, but these grates are made for specific purposes that are not for draining. For example, a grate placed over a window well next to a building will have smaller openings to allow for airflow but to keep as much dirt and leaf debris out of the window well. A stock grid has wider openings that are meant to make it hard for cattle to cross the grid and runoff, but these grids are not meant to act as drainage, too. For drains, specifically, you'll find narrow openings.
Yes, it can be annoying to see how even small leaf bits get trapped by the grid and cause minor flooding around the drain, but that actually means the grid is working. Ask the construction company if they have advice for keeping the grid as open as possible. If they can find customised grates, then you might be able to have the company create a pattern that is easier to clean off.
Contact a local company that offers custom grates for more info.