NOAA El Niño Advisory · Oct 8 · strong-to-very strong El Niño likely through Jan–Mar (>83%); 83% chance Oct–Dec is the strongest since 1950 · next update Nov 12
Tropical Storm Rachel · Oct 9–12 · Newport Beach's morning tide ran 20 in above the table; Long Beach Peninsula and Capistrano Beach red-tagged again
Kelvin wave · October · sea level +4 in now, about +6 in later this month, holding for months
California El Niño emergency · Sep 21 · emergency coastal permits decided within 24 h
King tides · Nov 24–26 · Dec 23–25 · Jan 21–22
Simulation
The ocean doesn't stop at the seawall. It comes in underneath.Hydrostatic siege. Structural equilibrium for tidally influenced soils.
Water-intrusion forensics and licensed repair for coastal homes, Malibu to La Jolla. We find every path the water took, document it for your insurer and the City, and close it.Forensic diagnosis and remediation of envelope and below-grade intrusion under tidal, surge and elevated-groundwater loading. Licensed general contractor, Hydrotech lineage since 1999.
Raise the tide. Raise the swell. Watch the beach, the wall and the house.
Section
Photo
Simulation
Photo
storm clock 0.0 h
Wave reaching the wall——
Water crest vs seawall top—wall top at +11 ft
Beach lost at the wall——
Seawall footing——
Water table vs slab foundation——
Pressure at house footing—seawater, 64 psf per ft
overtoppingseawall footinglower levelL3 system
Illustrative simulation, not a survey of any property. Tide elevations use NOAA predictions for the San Diego gauge (Dec 24 king tide about 7.6 ft MLLW) plus the Scripps El Niño and Kelvin-wave anomalies. Waves are depth-limited at the wall (height at most 0.78 of the water depth), so a lower beach and a higher tide let bigger waves reach it. Erosion is time-compressed; pressures are hydrostatic. Your lot gets its own survey and numbers.
Rebuild the beach.
The button above puts the sand back. On the coast that is public work, on public money and public timelines, and this month it is happening in real time. Here is what it does for a house, what it does not, and where we come in.Beach nourishment restores the profile that limits wave height at the wall (depth-limited breaking, H ≈ 0.78 d). It is a public-agency measure with its own permitting and funding cycle; it is not an owner-side control. The owner-side work begins at the seawall and runs inward.
sandWhat the cities are doing
Long Beach is trucking 50,000 to 100,000 cubic yards onto the Peninsula and has fast-tracked an $11.4 million dredge of about 415,000 more. Newport Beach is moving 100,000 cubic yards of Santa Ana River sand to West Newport this month. San Clemente puts its deficit at 2 to 4 million cubic yards and votes on Measure M, a sales tax for sand, in November. Sand is the buffer. It is also the first thing the next swell takes.Long Beach: 50,000–100,000 cu yd emergency placement from Oct 10, then an $11.4 M dredge (~415,000 cu yd) from the week of Oct 19. Newport Beach: ~100,000 cu yd from the Santa Ana River to West Newport, October. San Clemente: 2–4 M cu yd deficit; Measure M (1% sales tax, 10 years) on the November ballot. Nourishment is consumed by the same storms it is meant to blunt.
armorThe seawall and the revetment
Repairing or raising the wall is the coastal engineer's design and the armoring contractor's build, under the emergency permit the State now decides in 24 hours. The permit lasts 120 days; the follow-up permit still has to be won. We coordinate it. We do not build it.Shoreline protective devices: coastal engineer of record, armoring contractor, emergency CDP (24-hour decision, 120-day term, regular CDP to follow). Outside our licence class and our scope; we coordinate and sequence around it.
inwardEverything from the seawall in
The slab, the lower level, the deck ledger, the planters, the crawlspace and the water table under the house. While the sand is on order and the wall is in design, the water is already inside. We document it, stop the active path, and build the fix: drains and a sump that hold the table under the slab, a membrane on the walls, relief in the floor.Owner-side controls: perimeter drainage to a duplex sump with monitored drawdown, positive-side membrane on below-grade walls, sub-slab relief, cold joints sealed, ledger re-flashed, planters drained. Documented before, during and after; built to the engineer of record's plans.
Architect, engineer, counsel, adjuster or estate manager on the file?
the file
For the professionals on the file.
Architects, engineers of record, insurance counsel, adjusters, estate managers and family offices: this is how we work with you. We do not practise engineering. We find the water, document it to standard, and build to the stamped plans.
scope
What a forensic assessment includes
Site walk with you or the owner's representative; survey, plans and prior reports reviewed first.
Elevations tied to the owner's survey and reported in NAVD88 and MLLW, with the tide gauge named.
Moisture survey, pin and non-invasive, every reading placed on the floor plan.
Infrared survey of walls, slabs and ceilings, before and after any intervention.
Field water testing at openings (ASTM E1105, AAMA 501.2), electronic leak detection on membranes (ASTM D7877), flood testing where finishes allow (ASTM D5957).
A water-table observation point where the lot warrants it, logged through the king tides.
The beach and the seawall: the City, the Coastal Commission, the coastal engineer and the armoring contractor. We coordinate; we do not build them.
The structure: the engineer of record's stamped plans. We build to them and bring in the geotechnical and structural engineers the plans need.
Everything from the seawall inward: lower levels, slabs, deck ledgers, planters, retaining walls, crawlspaces, drainage, membranes, sumps. Ours.
Hydrotech lineage since 1999, including Construction Defect – Expert Witness assignments.
discretion
How the house is run
We work through the estate manager, the architect or the family office when that is how the house is run.
No photograph of the home leaves the file without written consent. The archive on this site shows sample entries, not clients.
One licensed contractor, one point of contact, from the first visit to the last inspection.
Your lot, your numbers.
The simulator's house is illustrative. Put in the elevations from the owner's survey and read the same model for that lot: water table under the slab, uplift, and the wave at the wall for each of this winter's sea states. Hydrostatic only; a survey and an engineer's letter replace it.
Sea state
Tide
Swell
Water table
Under the slab
Uplift
Wave at wall
Crest vs wall
Water table = 0.5 + 0.6 × tide (ft MLLW). Uplift = 64 psf per foot of seawater above the underside of the slab. Wave at the wall is depth-limited: at most 0.78 × the water depth over the sand plus 12% of the offshore swell. Crest = tide + 1.3 × wave at the wall. The L3 drawdown holds the table at +2.5 ft MLLW.
Not on the sand? Most water problems aren't.Common residential water intrusion, coastal zone.
You do not need an ocean view to have water in the house. These are the calls L3 Energy Construction takes most, from the beachfront to the low blocks behind it. Each one starts the same way: we find where the water gets in before anything is torn out.Rain-driven and ground-source intrusion in ordinary construction: roofs, fenestration, decks, stucco assemblies and slabs on grade. Source verified by test before any demolition.
stain on the ceiling after rain
Roof and flashing leaks
The stain is rarely under the hole. Water runs along the framing before it drops. We trace it back with a controlled water test and fix the entry point, not the paint.
Roof-to-wall, penetration and parapet flashing failures; entry located by isolation water testing.
water at a window or slider
Windows and sliding doors
It shows up on the sill or the floor in a wind-driven rain. Usually it is the flashing around the opening, not the glass. We spray-test it to prove which joint leaks.
Sill pan, head flashing and perimeter sealant failures; field tested to ASTM E1105 and AAMA 501.2.
drip or stain below a deck
Decks and balconies
A deck over a room is a roof you walk on. When its membrane or drains fail, the ceiling below tells you. We find the breach without flooding the deck or tearing it up.
Most California homes sit on a concrete slab. Concrete is not waterproof: ground moisture comes up through it, fastest at cracks and joints. Flooring cups, glue lets go, a white salt crust appears.
Slab-on-grade vapor drive and capillary rise; failed or absent vapor retarder; efflorescence at joints and the slab edge.
puddles against the house
Drainage and sump pumps
Water that sits against a foundation finds a way in. We regrade, install French drains and sump pumps, and give the water somewhere else to go.
Surface and subsurface drainage: grading, area drains, French drains, sump and discharge.
musty smell, spots on walls
Mold
Mold means something has been wet for a while. We remove it and fix what is feeding it. Cleaning mold without fixing the leak buys a few months.
Remediation paired with source correction; moisture verified dry before close-up.
water on the floor right now
Emergency dry-out
We pull the water, set drying equipment, and record what got wet before it dries, so your claim has evidence behind it.
Extraction and structural drying, with pre-drying moisture documentation for the loss file.
A pipe leaking under the slab is a plumber's repair. Not sure whether it is a pipe, rain or groundwater? Call us first. We find the source, then make the repair or bring in the right trade.
Look no further and pick up the phone!
One licensed contractor answers, finds the source, makes the repair and writes the report. Not a call center that passes your job to whoever is nearby.
CSLB #1149191 · Hydrotech lineage since 1999 · beachfront and the low-lying blocks behind it, Malibu to La Jolla
On the water: six places it gets in. We've opened all of them.Intrusion pathways, oceanfront envelope and substructure.
On an oceanfront lot, rain is the smaller problem. Tide is the bigger one. It arrives from the front, from below, and from the soil against the house, and it leaves salt behind.Loading on a tidally influenced lot is cyclic and comes from three directions: runup and spray on the envelope, lateral head on below-grade walls, and uplift under the slab as the water table tracks the tide.
deck ledger line · at FFE
Deck ledger and flashing
Where the deck bolts to the house. The single most common source of water inside coastal walls, and it rots from the inside.
Ledger-line flashing failure; absent or unterminated membrane at the rim; wet rim joist and sill plate, cavity mold within 48 h.
slab edge · cold joints
Slab edge and cold joints
Water wicks up through the slab edge and every joint in the concrete. Floors blister, baseboards swell, nothing on the surface explains it.
Capillary rise at the slab perimeter and construction joints; vapor drive under hydrostatic head; efflorescence and finish delamination.
below-grade walls · −9 ft
Lower levels and sunken garages
A lower level becomes a bathtub when the water table rises. On a king tide it can come up through the floor with no rain at all.
Negative-side intrusion through concrete or CMU under lateral head; no blindside membrane; sub-slab uplift once the table clears the slab.
planters · retaining walls
Planters and retaining walls
A planter against the house holds water against the wall around the clock. Retaining walls fail from the water behind them, not the dirt.
Saturated backfill without free-draining relief; no weep path, no low-permeability cap; lateral hydrostatic load on the stem.
sills · thresholds at grade
Windows and doors at grade
Sills and thresholds a few inches above a patio that floods. Spray finds the gap the installer left.
Fenestration water penetration at sill pans and sealant joints; verified by field spray test (ASTM E1105, AAMA 501.2).
crawlspace · subgrade
Under the house
Crawlspaces fill from below. You smell it before you see it, and by then the framing has been wet for weeks.
Subgrade saturation and capillary wetting of framing; salt-laden moisture accelerates fastener corrosion and mold amplification.
−3 ft
The sea doesn't stop at the first row of houses.Tidally influenced groundwater, inland of the shoreline.
Near the coast, the groundwater under your street floats on seawater. When the sea rises, the water table rises with it, blocks inland, with no wave in sight. It pushes up on every slab it reaches.Unconfined coastal aquifers respond to sea level. Daily tides damp out within a short distance of the shore; a seasonal rise such as an El Niño anomaly carries farther inland. Uplift on a slab is 62.4 psf per foot of fresh water above its underside, 64 for seawater.
The water table follows the sea. Daily tides fade within a short distance of the shore. A rise that lasts for months, like this winter's, carries farther inland.
What it looks like
A slab or garage floor that sweats. Flooring that lifts or cups. A white salt line at the base of walls. Rust at the bottom of door frames and posts. A sump pump that runs in dry weather.
Why this winter is worse
El Niño adds up to a foot of sea level on the Southern California coast and holds it there until spring. King tides stack on top on Nov 24–26, Dec 23–25 and Jan 21–22. The ground behind the beach is lowest on harbor islands, peninsulas, bayfront streets and old marsh.
What we do about it
Measure first: the water table, and the moisture in the slab. Then relieve it, with drainage and a sump where the ground allows, sealed joints and cracks, and a moisture barrier under the new floor.
Source: U.S. Geological Survey, Befus and others, Nature Climate Change, 2020. Rising sea level raises coastal water tables in California, because shallow groundwater floats on the seawater beneath it. Read the USGS summary.
−5 ft
September was the preview. Rachel was the first act.
Hurricane Marie's swell, Aug 28 to Sep 15, before El Niño had properly started. Then Tropical Storm Rachel, Oct 9 to 12, on a sea already running higher than the tide table. Every one of these lots has a house behind the seawall with the same question: what did the water do inside?
Capistrano Beach, Beach Road
First red tag. A deck destroyed, and coastal erosion undermined the slab foundation beneath it.
San Clemente puts its sand deficit at 2 to 4 million cubic yards and sends Measure M, a 1% sales tax for sand and fire protection, to November's ballot. Newport Beach brings its replenishment forward: about 100,000 cubic yards of Santa Ana River sand to West Newport later this month.
The Kelvin wave arrives. Sea level off California up to 4 inches above normal in early October, about 6 inches later in the month, under every tide that follows.
El Niño Advisory, strengthening: a strong-to-very strong El Niño is likely through January–March (more than 83%), Niño-3.4 at +2.1 °C, and an 83% chance that October–December exceeds every El Niño since 1950. Next update Nov 12.
Local emergency. The morning high tide came in 20 inches above the prediction, which the city's utilities director called record-breaking; 15 to 20 blocks flooded, vehicles stranded, water at front doors.
Rachel's swell broke through the boardwalk bulkhead that Hurricane Marie had stripped of sand. Nine buildings, 13 addresses, red-tagged on Seaside Walk; 64th to 66th Place evacuated. The City fast-tracks 50,000 to 100,000 cubic yards of trucked sand and an $11.4 million dredge of about 415,000 cubic yards.
The seawall is the City's and the Coastal Commission's fight. Everything from the seawall inward is ours. The order matters.
Document it before you dry it
Thermal imaging, moisture mapping and a cause-of-loss photo report, written for your insurer, your attorney and the building official. Once a restoration crew dries it, the evidence is gone.
Stop the active path
Temporary relief where water is still entering: pumped drawdown, sealed penetrations, protected openings. Done under the emergency permit window where the lot needs one.
Get the engineer's letter and the fix
A red tag lifts on an engineer's assessment and a licensed repair. We quarterback the geotechnical and structural engineers, then build to their stamped plans.
Filed by what the water did, not by room. Open a case to read it in three chapters: the failure, the diagnosis, the restored state.Case files indexed by failure mechanism. Each follows the same chronology: pathology, diagnostic reconstruction, restored state.
case 084 · tidal intrusionsample entry
Newport Coast ledge residence
mechanism tidal intrusionlevel −9 ft garage
Lower-level garage took water from below on three consecutive king tides. No perimeter drainage; capillary rise at the slab edge; the sump was never connected to anything.
restored state · dry through the Dec 2025 king tides · monitoring in place
mechanism ledger flashing decaylevel at finished floor
Ipe deck on a steel cantilever. The ledger flashing failed at year eleven; the rim joist stayed wet behind stucco for two winters and the wall cavity grew mold.
restored state · spray-tested at the ledger (ASTM E1105) · zero penetration
Slab heaving along a cold joint every winter as the water table rose with the season. Floor finishes failed three times before anyone measured the table.
restored state · table held 20 in below slab through the 2024–25 season
The diagnostic practice that started as Hydrotech Construction in 1999 is now L3's forensic division. Hydrotech's work included Construction Defect – Expert Witness assignments, so the findings are written to hold up when someone challenges them. We find the source before anyone opens a wall, and we write it down in a form your insurer and your attorney can use.Field diagnostics to published test methods, with cause-of-loss reporting suitable for claims, litigation support and building-official review. Hydrotech lineage: Construction Defect – Expert Witness.
Thermal imaginginfrared, surface temperature mapping
Wet framing and saturated concrete read cold. We map it before and after every intervention.
Moisture mappingpin and non-invasive meters, logged to plan
Every reading placed on the floor plan, so the pattern shows the path.
Field spray testingASTM E1105 · AAMA 501.2
Controlled water on windows, doors and walls to reproduce the leak on demand instead of guessing.
Electronic leak detectionASTM D7877
Pinpoints breaches in deck and plaza membranes without flooding or demolition.
Flood testingASTM D5957
Horizontal membranes held under water to prove they hold before finishes go back.
Cause-of-loss reportsfor insurers, attorneys, building officials
Photo-documented findings and the recommended remedy, in a form other contractors can bid from.
Residential construction
Nathan McDonnell starts building in Orange County.
Hydrotech Construction
Founded to specialize in water intrusion: rain leaks, building envelope, forensic reports. Construction Defect – Expert Witness. Licensed July 1999 for general building and flooring, CSLB #766196. Hydrotech page →
L3 Energy Construction LLC
CSLB #1149191. Coastal water intrusion, forensic to finished.
−14 ft
Questions homeowners ask us.
Short answers in plain words. If yours is not here, call.
The first 24 hours when seawater gets into the house
In this order. Documenting and drying happen the same day; documenting comes first.
Make it safe
If you smell gas, get out and call the gas company from outside. Switch off power to circuits that are wet. Do not enter a red-tagged house; a yellow tag says what you may do.
Stop the water if you safely can
Close the valve if it is a pipe. If it is the sea or the ground, there is nothing to close; move what you can above the water line and leave the rest in place for the photographs.
Photograph and video everything before it moves
Every room, the water line on the walls, the floor, the garage, the contents, the outside of the house and the beach or street. Phone timestamps are fine. Nothing gets dried, moved or thrown out before it is on record.
Take moisture readings
A pin meter on walls and floors, room by room, written down with the time. If you do not have one, we bring ours; the readings date the damage.
Open the claim
Call your insurer the same day, say you are limiting the damage, and send the photographs. Keep the City's tag notice if there is one. Wave and flood damage is often a flood-policy question; the record matters either way.
Start drying
Extraction, air movers and dehumidifiers the same day. Wet drywall and insulation that took seawater come out; the salt stays in whatever is left. Do not tear out beyond what has been photographed.
Find out what the water did underneath
A damp floor with no rain, a salt crust on concrete, doors that bind and new cracks mean the water is under the slab. That is a moisture survey, not a guess, and it is where we start.
Why is my floor damp when there is no leak and it has not rained?
Moisture is most likely coming up through the concrete slab. Concrete is porous, so ground moisture or a high water table pushes vapor and water through it, fastest at cracks, joints and the slab edge. Near the coast the water table rises and falls with the sea, so floors can turn damp in dry weather. A moisture test of the slab confirms it.
Can the ocean affect a house that is not on the beach?
Yes. Near the shore, groundwater floats on seawater, so a higher sea lifts the water table under streets that are blocks inland. The U.S. Geological Survey has modeled this along the California coast. The result is pressure from below on slabs, garages and buried utilities, with no flooding on the surface.
What is hydrostatic pressure, and what does it do to a slab foundation?
Hydrostatic pressure is the push of standing water on whatever holds it back. It grows with depth: about 62 pounds per square foot for every foot of fresh water, 64 for seawater. One foot of groundwater above the underside of a slab pushes up on every square foot of that floor, which is why water appears at cracks and joints first.
Who do I call for water in the house: a plumber, a roofer or a water-intrusion contractor?
Call a plumber when a pipe or fixture is leaking: the water is clean and constant, and the meter moves with every tap closed. Call a water-intrusion contractor when the water follows rain, tide or irrigation, or when nobody can tell where it comes from. L3 finds the source first, then makes the repair or brings in the right trade.
Should I dry out a flooded room first, or document it first?
Do both the same day, in that order. Stop the water if it is safe, photograph everything and take moisture readings, then start drying. Most insurance policies expect you to limit the damage, and the adjuster will want proof of what was wet. L3 records the damage and runs the dry-out in one visit.
Will a French drain or a sump pump fix a wet slab?
Often, when the water is coming from the ground. A drain collects water around or under the slab and a sump pump sends it away, which lowers the pressure on the concrete. It will not fix a roof, window or pipe leak, so the source has to be confirmed first.
Does L3 remove mold?
Yes. L3 removes mold and repairs the leak that caused it. Mold needs moisture, so removing it without fixing the source usually fails within months.
What does El Niño change for coastal homes this winter?
It raises the sea. NOAA's October 8 update says a strong-to-very strong El Niño is likely through the winter, with an 83 percent chance that October to December is the strongest since 1950. The Kelvin wave has already added several inches to sea level off Southern California, with king tides on Nov 24–26, Dec 23–25 and Jan 21–22 on top. On Oct 9 Newport Beach's morning tide came in 20 inches above the prediction. Higher water reaches seawalls and lifts the groundwater behind them.
Where does L3 Energy Construction work?
L3 works the Southern California coastal strip from Malibu to La Jolla: beachfront homes and the low-lying blocks behind them. It comes to the house: the assessment, the testing and the repair all happen on site. Call (949) 612-4046.
Is L3 licensed, and how long has it done water-intrusion work?
Yes. L3 Energy Construction LLC is a California licensed general contractor, CSLB #1149191. Its water-intrusion practice began as Hydrotech Construction in 1999, and Hydrotech's work included construction-defect expert witness assignments.
−15 ft
Tell us what the water did.Request a forensic site assessment.
One call, one team, from the diagnosis to the repair. Red-tagged lots get same-week assessments during storm season.