The short answer
Treat it as one chain, not three jobs: gutter, downspout, buried line, outlet. Clear the gutters, then run a hose down each downspout and go find where it comes out. If nothing appears at the daylight point, the underground section is blocked and the gutters were never the problem.
People treat gutters as a roof accessory. On a Lamorinda hillside lot they are the first stage of a chain that ends either safely downhill of the property or against your foundation — and the chain is only as good as its weakest link.
Follow the whole chain
- The roof surface sheds rain into the gutters.
- The gutters carry it to the downspout outlets.
- The downspouts carry it to ground level.
- The discharge puts it either onto the ground or into a buried line.
- The buried line carries it to a safe outfall.
- The outfall releases it somewhere it can go without coming back.
Break any one of those and the water arrives at your foundation. Most homeowners check stage two and assume the rest.
Stage by stage, what to check
Gutters
- Clear the full length, not just what you can reach easily. Coast live oak drops year-round, and the litter mats.
- Check the fall. Water should run to the outlets, not pond. Gutters sag over time, especially when they have been holding wet litter.
- Check the fixings. Wet leaf litter is heavy and pulls gutters away from the fascia.
- Look at the back edge. Water backing up behind a gutter runs down the fascia and into the wall top — a very common and misdiagnosed source of interior staining.
Downspouts
- Run a hose into the top and watch the bottom. If nothing comes out, there is a blockage in the spout.
- Check the elbows, which are where litter jams.
- Look for leaks at the joints, which put water directly onto the wall.
The discharge point — the one that matters most
This is where the majority of preventable foundation water comes from, and it is the cheapest thing on the list to fix.
A downspout discharging within a foot of the foundation is delivering the entire roof catchment of that section directly to your foundation and, on a raised-foundation house, straight toward the crawl space. Extend it six to ten feet, with a rigid extension rather than the folding plastic kind that gets kicked aside by a gardener.
Buried drain lines
- Run a hose into the inlet and find the outfall. Confirm water comes out.
- Check the inlet connection. Buried lines crack and separate at the downspout connection, discharging into the ground right at the foundation — with no sign at all above ground.
- Find the outfall and clear it. Outfalls silt up, get planted over, or get buried by a later landscaping job.
The wider hillside system
Beyond the roof drainage, most Lamorinda hillside lots have some combination of swales, area drains, catch basins, French drains and retaining wall drainage. All of it silts, blocks or collapses over decades, and none of it announces the fact.
- Pour a bucket into every area drain and confirm it goes somewhere.
- Lift the grates on catch basins. They fill with sediment level with the grate.
- Check retaining wall weep holes are open.
- Find your swales and check they have not been planted over or flattened.
- Look for a French drain — a strip of gravel, a cleanout, an outfall. If there is one and you have never maintained it, assume it needs jetting.
See hillside drainage 101 for the full picture.
Are gutter guards worth it under oaks?
Partially. Mesh and screen guards keep out leaves and small branches, which reduces clearing frequency meaningfully. They do not keep out the fine debris and oak catkins that eventually build up on top of and underneath them, and a guard that has silted over sheds water off the roof edge entirely rather than into the gutter.
Honest answer: guards reduce how often you need to clear, but they do not eliminate it, and they make clearing harder when it is needed. Under heavy oak canopy they are worth having and are not a substitute for an annual check.
The October job list
Half a day, once a year, before the rains
- Clear gutters full length and check the fall and fixings.
- Hose-test every downspout top to bottom.
- Extend every discharge six to ten feet from the foundation.
- Hose-test every buried drain line and confirm the outfall runs.
- Bucket-test every area drain and lift every catch basin grate.
- Check retaining wall weep holes are open.
- Clear crawl space vents of leaf litter.
- Walk the property during the first storm and watch where the water goes.
See the Burton Valley area page for how this plays out on the local slopes, and flooded basement and crawl space cleanup for what happens when it does not get done.
Frequently asked
How far should a downspout discharge from the foundation?
Six to ten feet, using a rigid extension rather than the folding plastic kind that gets kicked aside. A downspout discharging within a foot of the foundation delivers the entire roof catchment of that section directly against the building, and on a raised-foundation house that means straight toward the crawl space. It is the cheapest and highest-return fix on any hillside lot.
How do I check a buried downspout drain line?
Run a hose into the inlet and go and find the outfall to confirm water comes out. A separated buried line is the most insidious drainage failure there is, because everything above ground looks perfect — water goes into the downspout, disappears as expected, and then discharges into the soil next to the foundation. Hose-testing is the only way to catch it.
Are gutter guards worth it with oak trees?
Partially. Mesh and screen guards keep out leaves and small branches and meaningfully reduce clearing frequency, but they do not keep out fine debris and oak catkins, which build up on top of and beneath them — and a silted guard sheds water off the roof edge entirely rather than into the gutter. Worth having under heavy canopy, but not a substitute for an annual check.
When should I do this in the East Bay?
October, before the first serious system arrives. Doing it in December means working in the wet, competing for contractors with everyone else who left it late, and having already carried the risk through whatever storms came first. Most of the list is free and takes half a day once a year.