Photo examples of sidewalk grates and roadside basins
See below for photos of different types of underground structures in the wild that often hold standing water. Use this as a guide to help determine which structures to input.
Catch basins
Also called stormwater drains, catch basins live on the side of roads and drain into the sewer lines. The catch is, these basins often get clogged and retain trash and leaves that hold water. And some catch basins are designed to hold water — debris falls to the bottom, and water sits on top until it a reaches the level of the drainage pipes and flows out. Perfect for mosquitoes.
Manholes
Below manhole covers are often telecom vaults and other infrastructure that doesn’t drain to the sewer system. Water can get into the “pick holes” (holes in the cover that picks are inserted into to help lift them up) and collect in the bottom of the infrastructure creating a perfect mosquito breeding habitat.
Sidewalk grates
Some underground infrastructure is protected above by rectangular grates you can see down through vs. manhole covers. Same principle applies here though — water gets in and there’s no drainage.