Stormwater Drainage & Drywells in Vancouver, WA

Stormwater drainage and drywells handle the water that a wet Northwest winter puts on every property: roof runoff, surface water from uphill, and groundwater that rises into crawl spaces. French drain installation is one of the most searched drainage terms around Vancouver, and it is often paired with downspout lines and a drywell or other outlet.

Soil decides the solution

On the Missoula-flood gravels that underlie much of central and east Vancouver, like the USDA Sifton and Lauren soils, water drains very fast, and drywells usually work well. On older clay hills to the north and east, like the Hesson and Gee soils, permeability is slow to very slow, and water needs to be piped to a surface outlet instead. We dig a test hole when it matters.

French and curtain drains

A French drain is a trench with fabric, drain rock and perforated pipe that collects water and carries it away. A curtain drain across the uphill side of a lot intercepts water before it reaches the house. HomeGuide lists exterior French drains at $10 to $35 per linear foot and curtain drains at $1,500 to $8,800.

Drywells

A drywell is an underground chamber or rock pit that lets collected water soak into permeable soil. HomeGuide puts gravel drywells at $50 to $250, prefabricated plastic at $200 to $700 and concrete at $500 to $3,000 or more. Drywells are regulated, and cities and the county set rules on where they can go; we confirm before installing.

Crawl space water

Many Clark County homes have crawl spaces that stay damp all winter. Fixes start outside: regrading soil away from the foundation, tightlining downspouts to an outlet, and a perimeter or curtain drain where groundwater is the cause.

Timing

Drainage is easiest to design in winter, when you can see the water, and easiest to install in late summer and fall, before the rains.

Downspouts first

The cheapest fix is often at the roof. Downspouts that dump next to the foundation soak the soil the crawl space sits on. Tightlining them in solid pipe to a drywell or other outlet removes a large share of the water without touching the foundation.

Keeping drains clean

Fabric around the rock, cleanouts at bends and a clear outlet keep a drain working. Silt from bare soil is the most common reason drains fail, so we restore cover over the trench quickly.

Sump pumps and crawl drains

When a crawl space sits below the surrounding ground, an interior drain and sump may be needed in addition to exterior work. We do the excavation and trenching; the pump hookup goes to your plumber or electrician.