If your drains slow down or back up after it rains, water is probably getting into your sewer line where it shouldn't.
Written byNew Pro Plumbing·Reviewed byMiguel Lopez, Owner & Licensed Plumber, New Pro Plumbing (CSLB #974600)·Last reviewedSeptember 2026 · 8 min readQuick Answer
Sewer problems after rain usually mean stormwater or groundwater is entering the sewer through cracks, open joints, damaged cleanouts, or improper connections, overloading the line. We camera the line to find the entry points and seal them. In Marina del Rey, low-lying ground and high groundwater make infiltration a real factor for building lines.
Sanitary sewers are designed to carry wastewater, not rain. When stormwater or rising groundwater gets into the line, through cracks, open joints, a broken cleanout, or a downspout or area drain connected where it shouldn't be, the extra water can overwhelm the pipe and cause slow drains or backups. This page is part of our complete guide to sewer line repair in Marina del Rey.
Sewer Problems After Rain: Sewer problems after rain occur when stormwater or groundwater enters a sanitary sewer line through defects or improper connections and overloads it.
The EPA notes that sewer defects letting in stormwater and groundwater are one of the causes of sewer overflows. At the household level, the fix is finding the entry points. A camera inspection shows cracks and open joints, and a site check finds any improper connections.
In Marina del Rey, low-lying ground and high groundwater make infiltration a real factor for building lines. Low-lying areas and groundwater near the surface in Marina del Rey increase infiltration risk.
We look for downspouts, area drains, or sump lines tied into the sewer.
Broken or uncapped cleanouts can take in surface water.
We look for cracks and open joints letting water in.
Repair, line, or reroute, depending on the source.
Camera first, always. Every recommendation starts with a recorded inspection you can watch yourself, and a flat-rate price you approve before we start.
Low-lying ground and groundwater near the surface in many parts of Marina del Rey make infiltration a real factor. When storms saturate the soil, cracked building laterals and open joints can take in water, and below-grade garages and drains are often affected first. We check for improper connections and damaged cleanouts, camera the building line for infiltration, and seal what we find. For buildings with below-grade fixtures, we'll also check ejector pumps and backwater protection.
Marina del Rey is mostly condos, apartments, and townhomes built from the 1960s onward, so sewer problems here usually involve shared building lines as much as single-home laterals. Shared laterals and building drains mean a slow line in one unit is often a symptom of a problem further down the system. We start with a camera and share the recording with you, your board, or your property manager.
Not sure what your line needs? We camera it first, then quote a flat rate.
Get a Free Quote| Detail | Marina del Rey |
|---|---|
| Area | Marina del Rey, CA 90292 |
| Jurisdiction | Unincorporated Los Angeles County |
| Permits | LA County Public Works Building & Safety |
| Typical access | A cleanout or fixture; targeted excavation only when needed |
| First step | Camera inspection with a copy of the recording |
| Pricing | Flat-rate, in writing, before work starts |
| Availability | 24/7, including weekends and holidays |
| License | CSLB #974600, insured |
| Languages | English and Spanish |
Marina del Rey is unincorporated Los Angeles County, so plumbing permits come from LA County Public Works Building & Safety, not LADBS. LA County Public Works maintains the public sewer mains and can notify owners when a private lateral is affecting the main. We'll flag up front if any part of the work is in the street and needs additional County permits.
Example scenario below is illustrative, based on common situations we see. Details vary by property; not a specific customer.
A Marina del Rey building's garage-level drains back up during every major storm.
Our camera shows groundwater entering at cracked joints in the building lateral.
We line the lateral, and the garage drains stay clear through the next storm season.
New Pro Plumbing is family-owned and led by Miguel Lopez, and many Marina del Rey customers ask for him by name. Our trucks carry the camera, locating, jetting, and repair equipment most sewer jobs need. And when we leave, we leave no trace behind.
Also serving neighborhoods near Marina del Rey: Del Rey, Westchester, Culver City, Ocean Park. See all Westside service areas.
The Bottom Line
Rain shouldn't affect your sewer. If it does, water is getting in. We find the entry points on camera and seal them.
Rainwater or groundwater is likely getting into the line through defects or connections and overloading it. Sewer problems that appear only during or after rain point to infiltration: groundwater entering the sanitary sewer through cracks, joints, or improper connections. See the EPA’s page on sanitary sewer overflows.
It happens, especially in older properties. It’s generally not allowed and can overload the line. Downspouts or area drains illegally tied into the sanitary sewer are a common cause. That is a code violation in both the City of LA and unincorporated County.
Occasionally. That’s one reason some properties use backwater valves. We’ll help figure out whether the issue is your line or the main. The fix is sealing the entry points, usually by lining the lateral, and disconnecting any improper connections. See our sewer backup page for related symptoms.
Sealing cracks and joints with a liner or repair, fixing cleanouts, and removing improper connections. For a property with a history of rain-related backups, a backwater valve on the sewer service is worth considering as an added layer of protection.
Groundwater and runoff can enter through cracked joints or damaged cleanouts. Below-grade drains are usually affected first. For Marina del Rey properties in low-lying areas, tide and rain together can push infiltration higher. Sealing entry points with a liner is the fix.
This page was written by the New Pro Plumbing content team and reviewed for technical accuracy by Miguel Lopez, owner and California-licensed plumber (CSLB #974600). Agency rules are summarized from the official sources above; programs and requirements can change, so confirm current details with the agency. Nothing here is a quote. We confirm scope and pricing in writing before any work begins.
What’s new: September 2026, first publication.
If your drains slow down or back up after it rains, water is probably getting into your sewer line where it shouldn't.
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