If you’re looking to locate a drywell in the Portland area then we can probably help. Please see below for a short description of what drywells are, where they are normally located, and why you might want to find them.
A drywell is a hollow spot in the earth for rainwater to seep into the soil. A drywell can prevent rain runoff from going into the city sewer and overwhelming that system and it can prevent a downspout from pouring water on the ground surface, turning the area into a mud pit. Read the City of Portland article on drywells Here.
A drywell is created by putting a casing in a hole and connecting the gutter downspouts to it. The pipes and drywell are then buried. Normally constructed of either stacked and offset bricks in a dome shape (pre-1950s usually) or preformed perforated concrete rings (post-1950s) stacked on themselves. Some drywells are made of metal and these will eventually rust causing a sink hole.
The drywell is often between 1′ and 3′ in diameter and they tend to go down only around 5′, but sometimes much deeper. The pipes connecting the gutter to the drywell and the top of the drywell are often fairly shallow, often only 1′ or 2′ below the ground surface.
Homes can have multiple drywells or one single one. Not every home has a drywell. When a single drywell is used the gutters will connect along the perimeter of the home with rain drains and go out in one or two sections into the drywell. Modern drywells tend to be a shared drywell in the back corner of the yard. Homes from the 1950s can have each gutter with it’s own drywell. They are typically around 10′ from the back of the home and may be under a patio.
“The Oregon Plumbing Specialty Code (OPSC) 1126.96.36.199 requires that drywells be located no closer than 5’ from a property line and no closer than 10’ from a building.”
If you need to inspect the drywell for regular maintenance and you don’t know where it is then we can help. Under our ‘Private Utility Locating‘ services we can insert a traceable wire into the gutter downspouts and locate that path until it ends. Metal drywells are easily confirmed.
Call us at 503-939-9585 to discuss drywell locating.
Drywell Article on Wikipedia.
On allowing an exemption to the normal location of a drywell with information from the Bureau of Environmental Services (BES) https://www.portlandoregon.gov/bds/article/641338
City of Portland article on drywells.
City of Milwaukie drywell location requirements article.