Drainage Solutions Guide for Gig Harbor, WA

Q: What is the best drainage solution for a wet yard in Gig Harbor?

It depends on where the water is coming from. For groundwater intercepted before reaching the foundation, a French drain on the uphill side of the wet area is the standard solution. For surface water collecting in a low spot, a dry well or catch basin pulls water down and away. For runoff from gutters, downspout extensions buried 10 to 20 feet from the foundation move the discharge point. Most chronic wet yards in Gig Harbor need a combination of two or more of these.

Q: What size rock should I use for a French drain?

Use 3/4 inch clean crushed rock (no fines) wrapped in non-woven geotextile fabric. The clean rock keeps the drain free-flowing. Minus rock with fines clogs over time. Plan on 1 yard of 3/4 clean rock per 20 to 25 linear feet of drain at typical depth.

Q: How deep does a French drain need to be?

For surface drainage (yard, lawn, planting beds), 12 to 18 inches deep is typical. For foundation drainage, the trench needs to extend below the footing, which usually means 24 to 36 inches or more. For interceptor drains across a slope, depth depends on where you need to catch the groundwater seam, often 18 to 30 inches.

Q: Does a French drain need an outlet?

Yes. Water has to go somewhere. The outlet can be daylight (a lower point on the property where water can exit safely), a dry well (an underground infiltration basin), or a tied-in storm system if local code permits. A French drain with no outlet quickly turns into an underground bathtub.

Q: What is the difference between a French drain and a dry well?

A French drain is a linear system: a perforated pipe in clean rock that intercepts groundwater along its length and carries it to an outlet. A dry well is a point system: a buried gravel pit or commercial dry well that lets collected water infiltrate slowly into the surrounding soil. They're often combined: a French drain catches water, a dry well receives the discharge.

Q: Do you deliver French drain materials to Port Orchard and Bremerton?

Yes. Harbor Soils delivers 3/4 clean drainage rock, 1-1/2 clean rock, and other drainage products throughout Gig Harbor, Port Orchard, Bremerton, Silverdale, Poulsbo, Olalla, Purdy, Fox Island, and Key Peninsula. Same-day delivery typically available for orders before noon.

Drainage materials and complete-system guidance for Gig Harbor and Kitsap County. French drains, dry wells, swales, downspout extensions, and the rock and pipe to build them.

Wet yards are not a Gig Harbor accident. The combination of glacial till subsoil, 40+ inches of annual rainfall, and many older homes built before modern drainage standards means most properties in this region have at least one chronic wet spot. The good news: drainage problems are solvable with the right combination of standard techniques. This page covers the four drainage solutions that work in our region (French drain, dry well, swale, downspout extension), the materials we deliver, and how to pick the right approach for your problem.

Gig Harbor Service Area

We deliver drainage rock, perforated pipe (special order), and related materials throughout Gig Harbor (zip codes 98329, 98332, 98335, 98349) and adjacent Kitsap and Pierce County communities:

Gig Harbor: Downtown, Crescent Valley, Rosedale, Canterwood, Harborview
Artondale, Wauna, Fox Island (98335, 98333)
Purdy and the Key Peninsula (98349)
Olalla (98359), Port Orchard, Bremerton, Silverdale, and Poulsbo

Our yard at 11612 WA-302 in Gig Harbor is centrally located. Most weekday drainage rock orders deliver same day or next day.

To check delivery for your address: visit harborsoils.com or call 253-857-5125.

Diagnose the Problem First

The drainage solution depends on where the water is coming from and where it's collecting. Walk your property after a heavy rain and identify:

Surface water: standing water on the lawn or in beds. The water is on top of the soil.
Subsurface water: soggy areas with no obvious source, often appearing as moss patches or perpetually wet lawn. Groundwater is moving through the soil.
Foundation moisture: damp basement or crawl space, water pooling against the foundation, efflorescence on basement walls. Water is reaching the foundation envelope.
Roof runoff: water pouring off downspouts and washing soil, eroding mulch, or pooling at corners of the house.

Each problem has a different fix. Trying to solve a roof runoff problem with a French drain just relocates the wet spot.

Solution 1: French Drain (For Subsurface Water)

A French drain is the workhorse solution for groundwater intercepted before it reaches a problem area. A perforated pipe wrapped in clean rock and geotextile fabric catches water moving through soil and carries it to a discharge point.

French Drain Components

4-inch perforated pipe: solid plastic corrugated, perforations facing down (counterintuitive but correct: water rises into the pipe from below).
3/4 inch clean rock · $43.99 / yard. No fines. The rock surrounding the pipe must stay free-draining.
Non-woven geotextile fabric: wraps the rock and pipe to prevent fine soil from migrating in and clogging the system. Fabric is sold by the foot at most landscape supply yards.
Outlet: daylight, dry well, or tied-in storm system.

French Drain Installation Steps

Mark the run uphill of the wet area, with at least 1% slope toward the outlet.
Dig the trench: 12 to 18 inches wide, 18 to 24 inches deep for surface drainage. Deeper for foundation work.
Line trench with non-woven fabric, draping 12 to 18 inches up each side.
Add a 3-inch base of 3/4 clean rock.
Lay the perforated pipe with perforations down. Maintain 1% slope.
Fill rock around and over the pipe, 12 to 16 inches above the pipe top.
Wrap fabric over the rock (creates a "burrito" of fabric around rock around pipe).
Backfill with native soil or topsoil.

For full step-by-step including outlet options, see our French drain installation guide.

How Much Rock for a French Drain?

Drain Length	Trench (12 in wide × 18 in deep)	3/4 Clean Rock Needed
10 ft	—	~0.5 yards
20 ft	—	~1 yard
50 ft	—	~2.5 yards
100 ft	—	~5 yards

Solution 2: Dry Well (For Surface Water Discharge)

A dry well is a buried infiltration basin: a hole filled with clean rock, lined with geotextile fabric, that lets collected water seep into surrounding soil over time. Use one as the outlet for a French drain or to receive downspout discharge in a yard with no daylight outlet available.

Dry Well Components

Excavation: typical residential dry well is 4 ft × 4 ft × 4 ft. Adjust to expected water volume.
1-1/2 inch clean rock · $35.99 / yard. Larger void space than 3/4 clean. Roughly 2.5 yards fills a typical 4×4×4 dry well.
Non-woven geotextile fabric: lines the excavation to keep soil out of the rock.
Inlet pipe: from French drain or downspout. Solid (not perforated) on the inlet side.
Optional access tube: a vertical PVC pipe to inspect and clean the dry well.

Dry wells work best in soils that can absorb water. In heavy Gig Harbor till, perform a percolation test before sizing: dig a small test pit, fill with water, time how fast it drains. If you're getting less than 1 inch per hour, the dry well will need to be oversized or you'll need a different solution.

Solution 3: Swale or Surface Channel

A swale is a shallow grassed depression that moves surface water across a property. The simplest, lowest-tech drainage solution: useful when the wet area is broad and shallow, and the destination is a lower point on the property.

Swale Construction

Lay out the run with a consistent 1 to 2% grade toward the outlet.
Excavate a wide, shallow channel: typical residential swale is 4 to 6 feet wide and 6 to 12 inches deep.
Smooth the channel and seed with grass or plant native sedges (better for boggy bottom).
For high-flow swales, line the bottom with 1-1/2 round drain rock for a dry creek bed appearance that handles peak storm flow without erosion.

Solution 4: Downspout Extensions and Foundation Drainage

Most foundation moisture problems start with downspouts that drop water within a few feet of the foundation. The fix is straightforward: extend the discharge point at least 10 to 20 feet from the foundation.

Downspout Extension Components

4-inch solid drain pipe: ABS, SDR-35, or smooth-wall corrugated. Solid (not perforated) so water moves through without leaking.
1 to 2% slope from downspout to discharge.
Discharge end: pop-up emitter at lawn level, daylight on a slope, or tied to a dry well.
3/4 minus · $34.99 / yard. Backfill around the pipe in the trench.

For older Gig Harbor homes with chronic basement moisture, the downspout extension fix often resolves 70 to 80 percent of the problem before any further drainage work.

Common Drainage Mistakes

Using minus rock instead of clean rock in a French drain. Fines clog the system within 2 to 5 years. (Minus gravel is the right pick for driveways, paths, and paver bases — just not drainage. See our 5/8 minus gravel guide for what it IS good for.)
Skipping the geotextile fabric. Soil migrates into the rock, and the drain stops draining.
Perforations facing up. Pipe should be installed perforations down. Water rises into the pipe from below; perforations up just let surface water in and bypass the gravel layer.
Insufficient slope. 1 percent minimum (1 inch drop per 100 inches of run, or roughly 1 foot per 100 feet).
No outlet. A drain has to go somewhere. Daylight, dry well, or storm system.
Solving the wrong problem. Surface water and groundwater have different solutions. Diagnose first.

Drainage System Lifespan

A properly built French drain (clean rock, geotextile fabric, sufficient slope, working outlet) typically lasts 20 to 30+ years. The most common failure mode is clogged fabric or accumulated fine sediment over time, which is preventable with the access-tube inspection cleanout.

Drainage Rock Delivery: How It Works

Diagnose the problem. See the diagnosis section above.
Pick the rock and quantity. 3/4 clean for French drains, 1-1/2 clean for dry wells.
Place the order. Visit harborsoils.com/collections/crushed-rocks or call 253-857-5125.
Confirm access. Drainage rock is heavy: roughly 1.4 to 1.5 tons per yard. Tell us about steep, narrow, or soft access.
We deliver and dump. Standard drop is on driveway or flat staging area. From there, wheelbarrow or skid-steer to the trench.

Contractor & Commercial Orders

Drainage contractors and excavation crews working Gig Harbor and Kitsap County can order:

Volume pricing for 10+ yard orders
Multi-load coordination for larger jobs
Mixed-product loads (3/4 clean + 1-1/2 clean + minus backfill) where weight permits
Recurring delivery for active job sites

Reach the office at 253-857-5125 or [email protected].

Frequently Asked Questions

What is the best drainage solution for a wet yard in Gig Harbor?
It depends on where the water is coming from. Groundwater: French drain. Surface water in a low spot: dry well or catch basin. Roof runoff: downspout extensions buried 10 to 20 feet from the foundation. Most chronic wet yards in Gig Harbor need a combination of two or more.

What size rock should I use for a French drain?
3/4 inch clean crushed rock (no fines) wrapped in non-woven geotextile fabric. Plan on 1 yard per 20 to 25 linear feet of drain at typical depth.

How deep does a French drain need to be?
For surface drainage, 12 to 18 inches deep is typical. For foundation drainage, the trench extends below the footing (24 to 36 inches or more). Interceptor drains across a slope: 18 to 30 inches.

Does a French drain need an outlet?
Yes. Water has to go somewhere. Outlet options: daylight, dry well, or tied-in storm system if local code permits. A French drain with no outlet quickly turns into an underground bathtub.

What is the difference between a French drain and a dry well?
A French drain is a linear system that intercepts groundwater along its length. A dry well is a point system that receives collected water and infiltrates it into the soil. They're often combined.

Do you deliver French drain materials to Port Orchard and Bremerton?
Yes. Harbor Soils delivers 3/4 clean drainage rock and other drainage products throughout Gig Harbor, Port Orchard, Bremerton, Silverdale, Poulsbo, Olalla, Purdy, Fox Island, and Key Peninsula.

Order Drainage Materials for Your Gig Harbor Project

Visit harborsoils.com/collections/crushed-rocks to browse drainage rock products and pricing, or call 253-857-5125 to talk through your project.

Harbor Soils
11612 WA-302, Gig Harbor, WA 98329
253-857-5125 · [email protected]

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