South of Tigard, on the river

Waterproofing in Tualatin

The City of Tualatin says parts of town are in the floodplain and see local flooding in the wet season. Find out whether your house is in that part before any waterproofing is planned.

Call (503) 555-0120

Illustration of a wet street beside a wide river running high, with fallen leaves over a storm drain — Illustration

Do these two things first

Look up the address
Enter it at FEMA's Flood Map Service Center. The city's floodplain page sends homeowners to the same tool.
If you are in or near the shaded area, ask the city
Tualatin states that floodplain rules can apply even when the changes are only inside the building. A drain cut into a basement floor, a sump pit or a crawl space liner are all inside the building.

What the floodplain permit involves

The permit is called a Flood Hazard Area Development permit and is applied for through the city's online system.

The city may ask for an elevation certificate or other certified documents. Those have to be prepared by a surveyor registered in Oregon, which takes time and is a cost of its own.

Ask the waterproofing company whether it has dealt with this permit before and who will apply. Get the answer before a start date is set.

River water is not the same job as ground water

Ground water

Rain soaks in, the soil fills, and water seeps through the wall or up at the floor edge. This happens on high ground too.

Drains, liners and pumps are built for it. See basement waterproofing and crawl space encapsulation.

Flood water

The river or a creek rises over its banks and stands against the house. No interior drain is sized for that.

Here the questions are about insurance and what is kept at floor level. Most homeowner policies do not cover flood, and flood cover is sold separately.

When heavy rain is forecast

The city keeps a sandbagging station at 10699 SW Herman Road. Bring your own shovel. Its local hazards page links to a short how-to video.

Tualatin manages the storm drains inside its limits, so a grate buried in leaves on your street is one for the city. Clearing the leaves yourself, if the water is shallow, is quicker.

Test the sump pump before the storm and check the outlet pipe is not under water. Battery backups matter most on nights like that.

Extra questions for a Tualatin house

Is my house inside the mapped flood area, and have you checked?
Where will the pump discharge when the ground outside is already saturated?
Does the equipment you are proposing sit above the level water has reached before?

In Tualatin and seeing water?

Call and mention whether the house is near the river or a creek. It changes what the company looks at first.

Get a waterproofing company on the phone

For homeowners with water coming into a basement or crawl space, or a yard that drains toward the house.