Storm Drain Cleaning: Whose Responsibility and How to Fix Clogs

Storm drains collect and route rainwater away from yards, driveways, and structures. When they clog, the result is standing water, flooding, and the drainage problems that Seattle homeowners most want to avoid. This article covers the difference between private yard drains and public street drains, who maintains each, how to clean a clogged yard drain, and when to call a professional.

How Do I Clean Out a Clogged Storm Drain in My Yard?

Common types of private yard storm drains:

Catch basin: A square or round box, usually 12–18 inches across, with a grated lid. Collects surface water and connects to an underground pipe that routes water to the street, a dry well, or daylight.

Area drain / yard drain: A smaller, often round drain in low areas of the yard, patio, or driveway. Similar function to a catch basin but smaller.

French drain inlet: A trench or pipe covered with gravel that collects subsurface water. Less commonly cleaned because it’s subsurface.

Cleaning a catch basin (DIY approach):
1. Remove the grate (usually pries up or has bolts)
2. Remove accumulated debris — leaves, sediment, roots — from the basin
3. Check the outlet pipe at the base of the basin — clear any blockage visible at the pipe opening
4. Flush with a garden hose to confirm water flows freely through the outlet
5. Replace the grate

When professional help is needed:
– The outlet pipe is blocked beyond the basin — requires a drain snake or hydro-jetting to clear the underground run
– The basin is full of compacted sediment requiring a vactor truck to remove
– The system involves multiple connected basins you can’t see

Whose Responsibility Is the Storm Drain on My Property?

Private property drains: Any catch basin, area drain, or French drain on your property — inside your property line — is your responsibility. This includes installation, maintenance, and cleaning.

Public right-of-way drains: Curb inlets and drains in the street, sidewalk, or planting strip (the area between the sidewalk and curb) are Seattle’s responsibility, maintained by Seattle Public Utilities (SPU).

The property line question: If a catch basin is installed in the planting strip (between the sidewalk and curb), it may have been installed by the previous owner to manage downspout or yard water. These are often in an ambiguous location — the planting strip is city property, but a private drain installed there is often treated as the homeowner’s maintenance responsibility.

If unsure: Call SPU (206-684-3000) and describe the location. They can confirm whether the drain is in the public system.

Storm Drain Backing Up During Heavy Rain — What to Do

During a heavy rain event:

If it’s a street drain: The street is flooding because the city’s drain is clogged or overwhelmed. Call SPU’s 24-hour line. Don’t attempt to clear a street drain yourself — it’s the city’s infrastructure.

If it’s your private yard drain:
– The drain is overwhelmed or clogged
– Debris accumulation on the grate reduces inflow — brush off the grate surface so water can enter
– If the drain can’t keep up during heavy rain but clears afterward, it may be undersized for the flow it’s receiving
– If it doesn’t clear after rain stops, it’s clogged downstream

Immediate steps for a private drain backup:
1. Clear debris from the grate surface
2. After rain, open the basin and check the outlet pipe for blockage
3. If the basin drains after rain stops, the issue may be flow rate during peak rainfall — may need a larger drain or additional drainage
4. If the basin holds water after rain, the outlet is blocked — clean or jet the underground pipe

How Often Should Storm Drains Be Cleaned?

Private yard drains in Seattle:
– Catch basins in areas with deciduous trees: inspect and clean annually — fall leaf drop is the primary clog source
– Catch basins in paved areas: every 2–3 years unless there’s visible debris accumulation
– French drain inlets: every 3–5 years, or when drainage performance declines
– After any significant landscape work (new mulch, new plantings): inspect for sediment

Indicators that cleaning is needed now:
– Drain holds water longer than usual after rain
– Water is backing up around the drain during rain rather than entering it
– Visible sediment or debris accumulation in the basin

Street drains (not your responsibility): Seattle’s public storm drain system is maintained on a municipal schedule. If a street drain in front of your home is backing up, report it to SPU rather than attempting to clear it.

Clogged Storm Drain Causing Yard Flooding — What to Do

Step 1: Identify which drain is clogged. Walk the yard and find where water is not draining. Locate the downstream drain serving that area.

Step 2: Check the grate. If the grate is covered with leaves, debris, or sediment — clear the surface first. This is the simplest and most common problem.

Step 3: Open the catch basin. Remove the grate, look in the basin. If it’s full of sediment or debris, clean it out. Check whether the outlet pipe at the base is clear.

Step 4: Test the outlet pipe. Run a hose into the basin after cleaning. If water doesn’t flow freely out the outlet pipe, the pipe is clogged downstream — needs a drain snake or hydro-jetting.

Step 5: Call a drainage contractor. If the underground pipe is blocked and you can’t clear it with a garden hose, a contractor with a drain cleaning machine or hydro-jetter clears the pipe for $200–$500 depending on length and blockage.

Can I clean a storm drain myself? Yes for the basin cleaning. Underground pipe cleaning is where DIY has limits — a drain snake reaches 15–20 feet; a professional machine reaches further.

Can I Clean a Storm Drain Myself or Do I Need a Professional?

DIY-appropriate:
– Cleaning debris from the catch basin grate and basin
– Removing accumulated sediment from the basin (scoop, bucket, shop vac)
– Flushing with a garden hose to clear minor sediment from the outlet pipe
– Replacing a cracked or missing grate

Professional help needed:
– Outlet pipe blocked beyond reach of a garden hose (hydro-jetting or drain snake)
– Basin filled with compacted heavy sediment requiring vactor truck removal
– Underground pipes need to be located (utility locating service)
– The drainage system isn’t functioning despite a clear basin (blockage or grade problem further downstream)

Cost for professional cleaning:
– Drain cleaning machine (snake) on a catch basin: $150–$300
– Hydro-jetting a clogged catch basin and outlet pipe: $200–$500
– Vactor truck for heavy sediment removal: $500–$1,500

Storm Drain Clogged With Leaves and Debris — How to Clear It

The Seattle autumn problem: October through December, Seattle’s deciduous trees (maples, alders, cherries) drop leaves that accumulate on drain grates and eventually enter the basin. Prevention and maintenance at this time of year prevents most clogs.

Clearing leaf debris from grates:
– Use a garden rake or leaf blower to clear the surface weekly during peak leaf fall
– Never blow or rake leaves over a drain grate intentionally

Clearing leaves from the basin:
– Wear gloves — debris in catch basins can include everything that washes off a yard
– Scoop or vacuum accumulated leaves and sediment from the basin
– Rinse and confirm outlet pipe is flowing

If leaves have compacted into the outlet pipe:
– A drain snake breaks up leaf compaction in the first 10–15 feet of pipe
– Hydro-jetting clears compacted leaves further into the pipe run

Prevention: A leaf guard or basin filter insert catches debris before it reaches the outlet pipe. These require seasonal cleaning but reduce the frequency of full basin cleanings.

What Happens If a Storm Drain on My Property Is Clogged?

For your private drain: The drainage area it serves floods during rain. Depending on the location, this could mean:
– Standing water in the yard (inconvenient but usually not immediately damaging)
– Water pooling near the foundation (greater concern — can lead to basement seepage)
– Driveway or patio flooding (inconvenient and safety hazard)
– Water backing up into a low area of the structure (urgent)

For a street drain clogged with debris from your property: Seattle’s stormwater ordinances require property owners not to allow debris from their property to block public storm drains. If leaves or landscaping debris from your property routinely clogs a street drain, clearing the drain after leaf fall is courteous and expected.

Storm Drain Overflowing Onto My Property — Who Is Responsible?

If a public street drain overflows onto your property:
This is SPU’s responsibility. The street drain system is designed to handle normal runoff — if it’s overflowing onto private property during rain events it was designed to manage, that’s a public system problem. Report to SPU.

If a neighbor’s private drain overflows onto your property:
A neighbor whose drainage system routinely discharges onto your property has a nuisance situation that may rise to a legal dispute. The typical resolution is for the lower property to install its own drainage to capture the runoff — unfair from a “whose water is this” perspective, but the most practical fix.

If your property is a natural low point:
Surface water naturally flows to low points. If your property is lower than the surrounding area, some surface water collection is expected and not attributable to neighbors or the city.

How to Prevent Storm Drains From Clogging Repeatedly

Most common causes of repeat clogging:
– Deciduous trees directly over the drain grate (leaves)
– Landscaping runoff carrying sediment and mulch into the basin
– Downstream pipe with root intrusion creating a chronic restriction

Prevention:
– Leaf guards on grates during fall leaf season
– Bark mulch beds not immediately adjacent to drain grates
– Annual basin inspection and cleaning, timed for after peak leaf fall (November or early December)
– Root treatment in downstream pipes if root intrusion is the recurring cause

For root intrusion in underground pipes:
– Camera inspection of the underground drain pipe confirms root intrusion
– Root cutting + hydro-jetting clears roots temporarily
– Pipe lining (CIPP) eliminates joint entry points and provides a longer-term solution

FAQ

Q: How do I clean out a clogged storm drain in my yard?
A: Remove the grate, clear accumulated debris from the basin, and flush with a garden hose to test the outlet pipe. If the outlet pipe is blocked, a drain snake or hydro-jetting from a contractor clears the underground section. Cost for professional cleaning: $150–$500.

Q: Whose responsibility is the storm drain on my property?
A: Private catch basins, area drains, and French drains on your property are your maintenance responsibility. Street-level storm drains in the public right-of-way (curb inlets, street drains) are Seattle Public Utilities’ responsibility.

Q: How often should storm drains be cleaned?
A: Annually for catch basins in areas with deciduous trees (time cleaning for after leaf fall, in November or December). Every 2–3 years for drains in paved areas with minimal debris. Inspect after any landscaping work that might introduce sediment.

Q: Can I clean a storm drain myself?
A: Yes for basin cleaning — removing debris and sediment from the basin and flushing the outlet with a hose. For blocked underground pipes, a contractor with a drain cleaning machine or hydro-jetter is needed.

Q: What happens if I ignore a clogged storm drain on my property?
A: The drainage area it serves floods during rain. Depending on location, this can result in standing water near the foundation (risk of basement seepage), flooded driveways, or damage to landscaping. Address drain clogs before the rainy season begins.