In western Washington, public agencies or private property owners are responsible for maintaining stormwater facilities. All facilities, whether public or private, must meet the same state and local maintenance requirements for proper control and treatment of stormwater runoff.
Homes built before the 1980s typically drain to public streets or roadside ditches maintained by local government. In newer residential developments, however, one or more stormwater facilities could be part of the infrastructure.
Since at least the 1980s, local jurisdictions have required some form of stormwater treatment as a condition of development. Rules became more rigorous in the 1990s and now stormwater treatments systems must be in place when improving or constructing roads, parking lots, buildings and homes.