Yard & Surface Drainage in Tacoma, WA
Ponding lawns, soggy beds, and water sheeting across driveways, and why the fix in South Tacoma is different from the fix on the hill.
Read the Soil Before You Dig
Two Tacoma yards a few miles apart can need opposite solutions for the same puddle.
Yard drainage fixes standing water with a French drain, catch basin, channel drain, dry well, or piped downspouts. The soil decides which works in Tacoma: till lots need a pipe to an outlet, while outwash lots in South Tacoma, Parkland, and Spanaway can soak water into a dry well.
On the till hills, the North End, Hilltop, Fircrest, University Place, and the ridges toward Federal Way, water has no downward exit. It sits on the hardpan until it evaporates in May, so a dry well fills up and stays full, and the only thing that works is a drain that carries the water sideways to somewhere lower. On the outwash prairie south of the city, the deep gravel the Spanaway soil series is named for drains so fast that groundwater is rarely the issue. Water standing on those lots is surface water arriving faster than the immediate spot can absorb it, and the fix is often a dry well and better grading. A drainage contractor who tests the soil with a hole and a bucket of water before quoting is doing the job properly.
A yard that ponds is also an early warning. Standing water in the lawn is water sitting in the same ground that surrounds the foundation, and clearing it at the surface frequently prevents a crawl space problem a few winters later.
The Fixes
Yard French drain
A trench of rock and perforated pipe through the wet zone, collecting water and carrying it to an outlet. The main tool for a chronically wet strip of lawn on till. How it is built is on the French drain page.
Catch basins
Grated boxes set at the low points where water collects, feeding a solid pipe to the outlet. The answer for a spot where water sheets across the yard and pools in one place.
Channel drains
Long grated trenches across a driveway or patio that intercept water before it reaches the garage slab or the front door. Common on the sloped driveways of Tacoma's hillside streets.
Dry wells
A rock-filled pit that takes roof or surface water and lets it soak into the ground. Effective on the outwash gravel of South Tacoma, Parkland, Spanaway, and Lakewood, and useless on till, where it becomes a buried pond.
Downspout tie-ins
Running roof water in solid pipe to daylight, a dry well, or a permitted storm connection instead of dumping it at the foundation. The most cost-effective fix in the trade and often the first one a contractor recommends.
Where the Water Goes, and the Permit Question
Surface water follows the same rule as every other drain: it needs an outlet. Hillside lots can run to daylight. Outwash lots can use a dry well. Flat till lots without a low edge sometimes need a sump even for yard water. Inside Tacoma city limits, tying any private drain into the City storm system or working at the curb requires a Stormwater Construction or Repair Permit from Environmental Services, and Tacoma Municipal Code 12.08.030 prohibits sending yard, roof, or groundwater into the sanitary sewer. In unincorporated areas such as Parkland and Spanaway, Pierce County Planning and Public Works handles site development review. A contractor who works the county knows which office to call and whether your job needs one at all.