Wet winter water around the house

Tacoma's flooding brochure, a 2009 update, says to direct downspouts at least 10 feet from the foundation and to route sumps and foundation drains to storm drainage, not the sanitary sewer.

Revised November 4, 2026

First, is it groundwater or sewage?

The brochure draws this line itself. Its page says water coming through floors or window wells counts as stormwater or groundwater, not sewage. Sewage coming up from a drain is a different emergency.

Tacoma's wastewater resources page gives Sewer Transmission's number, (253) 591-5585, for sewage rising inside while no water is running, and points slow drains to a private service. That number is Tacoma's. Elsewhere, use the find-your-sewer page to learn who takes your wastewater, then call that office.

When sewage comes back up, quit running water and hold people and pets well back. If water has reached wiring or a sump pump, stay out of it; the most this atlas suggests is a breaker you can reach from a dry spot, then a licensed electrician.

Where should downspouts go?

Away from the house, and the Tacoma brochure's page gives a distance: at least 10 feet from the foundation, best piped to a street gutter or ditch. Tacoma's inclement weather page adds that clearing storm drains, downspouts and drainage ditches of leaves and debris helps prevent urban flooding. Tacoma's Stormwater Management Manual also carries a downspout dispersion practice, BMP L603, which we saw only as a search summary.

All of this is Tacoma's. Other places may word it differently, and we did not find matching homeowner guidance from them.

Two spots need extra care wherever you live:

• A drainfield. Tacoma recommends diverting downspout water away from it. See the peninsula septic page for who regulates yours.
• A bluff or steep slope. Ecology wants runoff carried away from the slope, and the planning office comes first. See who to ask about bluffs.

Sumps, foundation drains and the sewer line

These belong on the storm side, according to the brochure's page, which names roof drains, sumps and foundation drains together. It also mentions a sump pump with a backup generator, and considering a backwater valve for low floor drains.

Whether either fits your house is a question for a licensed plumber and your permit office. Tacoma says it requires permits for sewer or stormwater connections, repairs and special discharges, so changing where a drain empties is not a free choice there. Elsewhere, start with the plumbing permit counter for your place.

Crawlspace water and footing drains

We could not confirm any official homeowner guidance on these beyond that 2009 brochure. We also found nothing on what a city requires for stormwater at an existing house. So this page gives no depth, no slope and no fix.

If water stands in a crawlspace every winter, ask two questions in this order. Does your city's public works or stormwater staff know of a drainage problem on your street? Then, what does a licensed plumber or civil engineer find on site? Any trench means calling 811 first, and a trench in a right-of-way falls under each city's contractor rules.

Where the public system stops

Tacoma says its stormwater system moves water toward Puget Sound and does not treat it first. It also says the Stormwater Utility finances drainage in city streets and on city-owned property. That wording does not mention private lots, so ask before assuming the utility will look at a wet yard.

Once a plumber or your city has settled where a drain may go, the pipe is the last decision. One page for comparing sizes is PVC pipe. The same team runs PlumbingSupplyAndMore and this site.