Fall Sewer Checklist for San Diego Homes Before the Rains Come
San Diego doesn't have a ground freeze to prepare for. What it has is a switch. Sometime in November the first Pacific storm arrives, the clay soil that's been shrinking since May takes on water and swells, and every marginal joint, root mat and belly in an old sewer line gets tested at once. The dry weeks between now and then are the easiest time of the year to check a sewer line and the cheapest time to fix one. This is the list.
1. Find your cleanout, or find out you don't have one
Walk the front of the house and the side yard nearest the street. You're looking for a capped pipe, three or four inches across, sticking a few inches out of the ground or flush with a concrete collar. Two of them close together is a two-way cleanout, which is the good kind. If you find nothing, and the house is from before about 1970, you probably don't have one. Adding a two-way cleanout at the property line is $400–$1,200 and turns every future service call from a pulled-toilet job into a twenty-minute one. Do it now, in dry dirt, not in January.
2. Run the lowest drain hard
Fill the tub or the shower closest to where the lateral leaves the house and let it go, then run the washer through a drain cycle right after. If the tub drains slowly, gurgles or takes water back, the main line is partly blocked. That's a root mat or scale that's been building since spring and will close up in the first week of rain. Get it jetted and cameraed now.
3. Look at the ground over the line
The lateral usually runs from the front of the house straight to the street; on older central-city lots it may run to the alley. In September the lawn over a leaking joint is the one green stripe in a brown yard, and a low spot or a dip in the sidewalk over the pipe means soil has been washing into a break. Either one is a camera call before the rain makes the ground too wet to read.
4. Check where the roof water goes
Sewer lines in San Diego are separate from storm drains, and downspouts shouldn't be connected to the sanitary sewer. Some older houses have a downspout or a patio drain tied into the lateral anyway, decades ago, illegally. When the rain comes, that connection dumps hundreds of gallons into a 4-inch pipe that's half full of roots, and the result is sewage in the shower during a storm. If a downspout disappears into the ground near the house and you can't find where it comes out, have it traced.
Legitimate yard drainage matters for the opposite reason. Downspouts that dump against the foundation keep the clay under the slab wet all winter, which is how slabs heave and under-slab cast iron cracks at the hubs. Extend them.
5. If it backed up last year, don't wait for this year
A line that backed up last November or December will back up this one. The ground movement that shifted a joint will shift it again. This is the month to price the real fix. A spot repair on a single joint is $1,500–$4,000; a liner or burst on the whole lateral is $6,000–$20,000, and both are easier to schedule now than in the second week of rain when every crew in the county is running emergencies.
6. Book the camera if the house is old and you've never had one
A 1950s house with an unknown lateral is a house with an unknown $10,000 bill. A camera inspection is $250–$500, recorded, and if the line is sound you're done for a few years. If it isn't, you've got two months of dry weather to fix it in.
The short version
| Task | Time | Cost | Why now |
|---|---|---|---|
| Locate or add a cleanout | 10 min / half day | $0 / $400–$1,200 | Dry dirt, no emergency |
| Tub-and-washer drain test | 15 min | $0 | Catches a partial block before rain |
| Walk the line for green or low spots | 10 min | $0 | Easiest to see in a dry yard |
| Trace mystery downspouts | Half hour | $0–$300 | Stops storm water entering the sewer |
| Extend downspouts away from the slab | Half hour | $30–$150 | Keeps clay from swelling under the house |
| Jet and camera a slow or rooty line | 2 hours | $350–$800 plus $250–$500 camera | Roots have been growing since June |
| Fix the joint that failed last year | 1 day | $1,500–$20,000 | Crews and ground both available |
What the rain does to a sewer line here
For anyone wondering why a dry city needs a rainy-season checklist: the sewer main under the street isn't supposed to take rainwater, but old mains and old laterals leak inward as well as outward. When the ground is saturated, groundwater gets into cracked pipes, the whole system runs fuller than usual, and a lateral that was draining slowly into a half-empty main drains not at all into a full one. On the lowest streets near the bay and the river valleys, the main itself can surcharge for a few hours in a big storm. Your lateral can't do anything about that, but a lateral with no roots and a proper cleanout is the difference between a slow tub and a flooded one when it happens. Who owns the sewer lateral covers what to do if it's the main and not your pipe.
Next month we'll get into the root-killing products people reach for in the fall. This month, do the drain test. It takes fifteen minutes and it's the one item on this list that finds the most problems.
7. Know what to do if it backs up in a storm
Write this down and put it where everyone in the house can find it.
- Stop running water. No showers, laundry or flushing.
- If there's a yard cleanout and it's safe to reach, open the cap slowly. Water coming out there means the blockage is downstream, and opening it can keep sewage out of the house.
- Check with a neighbor. If they're backing up too, it may be the main. Call the agency that bills you for sewer.
- If it's only your house, call for a clearing and ask for a camera on the same visit.
- Photograph any damage before cleanup.
8. Write down what you found
Keep a short note with the date, which drains were slow, what the ground looked like, and any work done. Add the camera file if you got one. Next fall you'll know at a glance whether things are getting worse.
Common questions
Is a fall sewer checklist worth doing on a newer house?
Yes, in a shorter form. A house built after about 1975 on ABS is less likely to have roots or rust, but downspouts, yard drainage and the cleanout still matter. Skip the camera unless something is slow.
What if I rent?
Do the drain test and tell the landlord in writing if anything is slow or wet. The lateral and the repair are usually the owner's job. Report problems early so they're fixed before the rains.
How long does the whole list take?
About an hour for the do-it-yourself checks. A jet and camera, if you need one, takes two hours on a normal visit.
What's the single most useful item if I only have time for one?
The tub-and-washer drain test. It costs nothing, takes fifteen minutes, and catches a partly blocked main line before the first storm closes it. If the tub drains fine with the washer running, the line is probably flowing well enough for now.
Items people skip, and shouldn't
- The yard drains. A patio drain tied into the sewer can flood the house in one storm.
- The cleanout cap. A cracked or missing cap lets dirt and rain in. Caps are cheap to replace.
- The neighbor's tree. Look over the fence. Roots don't stop at property lines.
Need sewer line work in San Diego?
Call for a free estimate. Mon–Sat 7am–7pm.