French Drains & Drainage Systems in Gig Harbor, WA

Drainage & French drains in Gig Harbor: what to know

A trench more than one foot deep reaches the grading list, and so does an excavation of 50 cubic yards or more. The small-excavation exemption covers cuts under one foot only, with conditions such as not obstructing a stream or surface water. We measure each trench and settle its alignment before the first cut, so the review is resolved in advance.

Where the water goes decides the rest. A tie-in to city stormwater or private stormwater infrastructure falls under the civil permit list, and a pipe or structure placed inside the right-of-way falls under the encroachment permit. The 2023 stormwater manual sets the minimum requirements, and we confirm which apply to the lot. Parcels within 200 feet of the ordinary high water mark also fall in shoreline jurisdiction, so we check that boundary before the outlet is set.

Permits and rules in Gig Harbor

We check the trench depth and volume against the grading list, confirm whether any pipe or structure enters the right-of-way, and verify whether a tie-in reaches city stormwater infrastructure. Downspout tightlines are planned on the lot, and we confirm the outlet with Public Works before a trench opens.

Rules change and vary by parcel, so we confirm the current requirements with the city before we start.

How we approach it

Follow the route surface water takes toward the low spot
Measure trench depth and volume against the one-foot and 50-yard lines
Keep pipes and structures out of the right-of-way unless permitted
Confirm any stormwater tie-in and minimum requirements before the first cut

For the full process, see our Drainage Systems & French Drains page.

Questions from Gig Harbor homeowners

Which discharge points fit a Gig Harbor French drain?

Either onto soil on your lot with enough capacity to absorb the discharge, or into a city stormwater connection that the city approves. A pipe placed inside the right-of-way needs the encroachment permit, so the outlet is fixed before any trench opens.

Which permits reach a French drain in Gig Harbor?

Depth, volume, and the outlet decide it. A trench more than one foot deep reaches the grading list, and a stormwater tie-in or right-of-way pipe reaches the civil or encroachment permit, so we check each before work starts.

Does a Gig Harbor yard fed by a slope need an interception drain?

Identifying the source comes first. Water arriving from higher ground may call for an interception drain, and the slope needs a check first, so we look at grade and soil before we commit to a layout.