By Giovanni Longo, third-generation master plumber and certified Flood Mitigation expert, Flood Brothers Plumbing
Forecast note (as of Nov 5, 2026): NOAA’s Climate Prediction Center has an El Niño Advisory in effect and expects a strong-to-very strong El Niño through January–March 2027, with chances remaining above 83% (CPC ENSO discussion, Oct 8, 2026; CPC status update, Nov 2, 2026). The National Weather Service in Los Angeles (AFD 12:43 PM PST Nov 5) keeps dry offshore weather through about Wednesday, a chance of light rain Thursday, Nov 12, then wet and unsettled weather from about Friday, Nov 13 into that weekend, with ensembles showing decent chances of widespread 1+ inch totals though timing and amounts remain uncertain (NWS Los Angeles AFD). NWS San Diego likewise flags a large trough late next week with substantial rain possible but low confidence in the details (NWS San Diego AFD). El Niño raises the odds of a wet winter, but it doesn’t guarantee one. Check weather.gov/lox before each storm.
On its south side, Sherman Oaks climbs into the hills fast. Many of the homes there are mid-century builds, with older drain lines and yards graded decades ago. When heavy rain comes, the water heads downhill to the flats and goes through your property on the way.
What I see in the Sherman Oaks hills
- Older clay or cast-iron drains. Many of these yard and sewer lines have been in the ground for decades. Roots and cracks slow them down, and a storm finds every weak spot. A camera inspection before the season tells you where you stand. See our Sherman Oaks leak detection page.
- Driveways that drop to the garage. Plenty of homes here sit below street level. Water off the street goes down the driveway and into the garage.
- Downspouts tied into old buried lines. If those lines are crushed or clogged, the water bubbles up right next to the foundation. Pull the downspout off the line and use a temporary extension pointed away from the house.
- Neighbors uphill. Their runoff becomes yours. A friendly conversation now helps everyone.
If water already got in, see our Sherman Oaks flood and water damage repair page.
The hillside basics I check on every hill home
- Runoff from above: water from the slope, the street and neighbors’ lots all lands on you.
- Retaining walls: weep holes and the drains behind the wall have to flow. When they clog, water pressure builds up behind the wall.
- Debris in drains: brush, leaves and soil wash into area drains and plug them fast.
- Driveway runoff: steep driveways carry water straight to the garage.
- Lower floors: rooms set into the hillside take water through walls and doors.
Warning signs that mean "leave and call 911": cracks opening in the ground or walls, tilting trees or fences, sudden mud or debris flow, or doors that suddenly stick. A pump doesn’t fix a moving slope. Follow evacuation orders from your city or county.
The pump setup for a hillside home
On a hill, gravity does part of the work. Put the pump at the low spot where water collects, usually the garage threshold, a lower patio or a window well. Then run the hose downhill to the street. If the curb sits above the low spot, buy a pump rated for that lift. Full guide: pump, hose and outlet.
Safe when it’s set up right: the electrical part
Water and electricity can mix safely only when you set them up correctly. Here’s how I set up every pump:
- Plug into a GFCI-protected outdoor outlet only, and test it first: press TEST (power should cut off), then RESET. If it won’t trip or won’t reset, don’t use it.
- Use an outdoor-rated, heavy-gauge extension cord (12 or 14 gauge), as short as you can get away with. Skip thin indoor cords and power strips.
- Keep every plug and connection off the ground and dry. Hang it on a hook, set it on a bucket, or put it in a weatherproof connection box.
- Never handle the pump, cord or plug while you’re standing in water.
- Unplug before you touch, lift or move the pump. Every time.
- If water reaches an outlet, appliance or your electrical panel, get out and stay out. Call a licensed electrician or your utility. Don’t try to pump your way out of that one.
Learn more about our service in Sherman Oaks and about water damage restoration.
Need a hand before or during the storm?
Call or text 855-840-7800. A live person answers 24/7, and we offer same-day service. Flood Brothers Plumbing is licensed, bonded and insured (CA License C36-985487), we’ve been at this for more than 15 years, and we work directly with your insurance company. If water already got in, see our water damage restoration service: water removal and drying, odor treatment, tarps and board-ups.
Gio’s $99 Special
Before the El Niño rains and the holidays, get a sewer mainline snake plus camera inspection for $99. Mention "Gio’s $99 special" when you call or text 855-840-7800. Mention the special when booking; valid through 12/31/2026. See Gio’s $99 Special.
FAQs
My Sherman Oaks house sits below the street. How do I keep water out of the garage?
Clear the driveway drain, set a pump at the garage threshold, and run the hose to the street gutter.
My downspouts go into an underground pipe. Is that a problem?
It can be, if the old line is clogged or crushed. Water backs up next to the foundation. A temporary surface extension pointed away from the house helps.
Should I get my drains inspected before the rain?
On older hillside homes, yes. A camera inspection shows roots and breaks before a storm finds them.
Do you offer same-day service in Sherman Oaks?
Yes. Call or text 855-840-7800, 24/7.
