Stormwater management - Southwest Washington

Catch basin

A catch basin with a lot of sediment buildup.


Trash has collected inside this drywell.

Vault filter

This stormwater filter vault has a lot of sediment buildup, indicating that the filter needs to be replaced by professionals.





Catch basin, drywell, manhole, and vaults

Maintenance is needed if you see these signs
• The facility drains slowly after a rain storm.
• Leaves, trash and other debris slow or stop outflow or filtration.
• There is more than ¼ - ½ inch of sediment on the cartridges.

Confined space warning signConfined space warning for underground facilities
Due to potential dangers, only trained and certified persons should enter confined spaces. These are defined as:
• Large enough that an individual could fully enter the space and work.
• Having limited or restricted entry or exit.
• Not primarily designed for human occupancy.
For more information visit Washington State Labor & Industries confined spaces rule.

Checklists for maintenance and recognizing and fixing problems (PDF files)
Catch basin
Vault - stormwater filter
Vault - vortex sedimentation
Vault - closed detention system

Field inlet
Flow control structure/flow restrictor
Access road
Fence, gates, signs