In Washington State, where rain can come down in sheets and stick around for days, managing
stormwater runoff isn’t just a seasonal concern—it’s a year-round necessity. One of the most
practical and cost-effective ways to protect your property and septic system from excessive
water is by installing a dry well. These simple underground structures play a powerful role in
controlling drainage and safeguarding your soil.
A dry well is an underground chamber that collects and disperses excess water from roof
gutters, downspouts, sump pumps, or surface runoff. Once water enters the dry well, it slowly
soaks into the surrounding soil, rather than pooling on the surface or saturating critical areas like
your septic field or foundation.
Dry wells help prevent erosion, reduce the risk of backups, and limit flooding near your home.
They’re especially beneficial in areas with clay soil or poor natural drainage—conditions
common across much of western Washington.
Too much water in the wrong place can overload a septic drain field, leading to premature
system failure, backflow issues, or soggy, unusable ground. By directing excess water into a dry
well, you:
● Reduce the volume of water reaching the septic leach field.
● Prevent surface pooling and erosion.
● Maintain healthier, more absorbent soil in critical drainage areas.
Dry wells act like pressure-release valves for your yard, keeping water where it should be and
away from where it can do harm.
If you’re thinking of installing a dry well, it’s important to plan carefully. Poorly placed or
undersized dry wells can do more harm than good.
Here are a few things to keep in mind:
● Location: A dry well should be installed at least 10 feet away from the house and at
least 50 feet from a septic system to avoid over-saturation. It should also sit downhill
from structures when possible.
● Capacity: Size the dry well according to how much water you need it to handle. The
more roof space or drainage area feeding into it, the larger the dry well should be.
● Materials: Most modern dry wells are made from plastic chambers or concrete rings with
gravel surrounds. The chambers should be perforated to allow gradual water release.
● Drainage Layer: A layer of gravel beneath and around the dry well improves percolation
and prevents clogging.
Like any drainage structure, dry wells require occasional maintenance to stay effective:
● Clean out gutters and downspouts regularly to prevent debris from entering the system.
● Check the dry well inlet after heavy storms to ensure it’s not clogged.
● Once a year, inspect the area around the dry well for signs of overflow or soggy ground,
which may indicate the need for service or expansion.
While DIY kits exist, dry wells are most effective when installed by experienced professionals
who understand soil conditions, runoff patterns, and septic compatibility. Improperly installed
systems can fail to drain properly or cause more damage than they prevent.
At Drain-Pro, we assess your site conditions, determine the best drainage solutions for your
property, and install systems that work in harmony with your existing septic or stormwater setup.
With Washington’s frequent rains, investing in proper runoff management is a smart move. Dry
wells provide an affordable, efficient way to manage excess water and protect your home, septic
field, and yard from avoidable damage.
If you’re noticing standing water or suspect your septic system is taking on too much, Drain-Pro
is here to help. Contact us today to discuss drainage options and keep your property dry, safe,
and functioning at its best.
