(650) 844-3807

License #838772

Peninsula Landslide Repair: Hillside Foundation, Slope Stabilization & Drainage Experts

Peninsula Landslide Repair has seen firsthand how heavy winter rains and shifting soil can turn a peaceful hillside home into a real source of stress. As a licensed Class A General Engineering Contractor, our local crew has been combining expert engineering with hands-on hard work to keep Peninsula properties on solid ground since 2003.

  • Track Record & Experience: Over 23 years of experience completing 650+ hillside residential and commercial slope projects across the Peninsula.
  • Speed & Response: On-site engineering evaluations are scheduled within 1–3 business days; typical project timelines range from 1 to 4 weeks utilizing our 3 specialized field crews.
  • Pricing & Estimates: Minor repairs and water control services typically range from $5,000 to $30,000, while major structural slope repairs and foundation stabilization range from $50,000 to $500,000+ depending on engineering scope.
  • CSLB-Compliant Payment Terms: In strict accordance with California law (CSLB § 7159), we require an initial down payment of $1,000 or 10% (whichever is less), followed by clear progress payments as project milestones (site mobilization, drilling, and shotcrete application) are met and inspected.
  • Geotechnical Engineering Assessments: Site investigations, soil testing, and PE/GE stamped geotechnical reports required for steep-slope permits.
Talk to an Expert

GET A FREE ESTIMATE

Start the repair with a professional evaluation and estimate.

5 Signs of a Landslide or Failing Slope You Should Not Ignore

Ground & Foundation Cracks

Curved cracks in your yard along the slope edge, widening gaps in driveways, or new diagonal cracks in foundation walls and drywall.

Leaning Structures & Trees:

Retaining walls bulging outward from trapped water pressure, tilted fence posts, or trees leaning downhill.

Sticking Doors & Windows:

Window and door frames shift out of alignment as the foundation settles, causing doors on the downhill side of the house to bind.

Water Seepage & Soggy Ground:

Soggy ground days after rain, water seeping directly out of the hillside face, or muddy water pooling behind walls.

Soil Bulging at the Base of the Hill:

A mound or bulge of pushed-up earth forming at the bottom of your slope, often accompanied by buckled landscaping or crushed drainage ditches.

Pro Tip: Mark the edges of any ground or wall crack with pencil or tape and note the date. If it expands over days or weeks, movement is active and requires professional evaluation before the next rainy season.
0+

Projects Completed

0+

Cities Covered in the Peninsula

0

Years of Experience

WHAT WE OFFER

Residential Landslide Repair and Hillside Home Protection

Hillside homes on the Peninsula depend on four connected systems: a foundation anchored below unstable soil, retaining walls that hold back grade, drainage that controls water, and surface protection that limits erosion. We assess and repair each one so they work together to keep your property stable.

Hillside Foundation Repair

On sloped lots, foundations often fail because the soil beneath them creeps downhill or settles after heavy rain. Warning signs include diagonal drywall cracks, sticking doors, sloping floors, and gaps between the house and attached decks.

We start with a site inspection and, when needed, coordinate with a geotechnical engineer. Repairs are matched to soil conditions and the home's structure:

  • Drilled caissons (piers) that extend into stable bedrock or firm soil
  • Grade beams that connect caissons and carry the building load
  • Underpinning to deepen or strengthen existing footings
  • Helical or push piers where access is limited

All structural work follows engineered plans and local permit requirements in San Mateo and Santa Clara Counties.

Retaining Wall Repair

When a wall begins to lean, bulge, or crack, it indicates that the slope behind it is already actively moving. Identifying and addressing these warning signs early prevents catastrophic slope failure and avoids costly property damage down the road.

Hillside Erosion Control

Erosion removes topsoil gradually, exposing roots and undermining walls and footings. Across the Peninsula, coastal fog, winter storms, and sandy soils in areas like Pacifica and Half Moon Bay can speed up this process.

We use methods sized to the slope's angle and condition:

  • Erosion control blankets made of coir or jute to hold soil while vegetation establishes
  • Hydroseeding with native, deep-rooted plants
  • Pipe and board systems for small, shallow slope repairs
  • Rock riprap at drainage outlets and steep cuts

Erosion control works best after drainage is corrected. We address both together so new plantings and surface protection are not washed out by uncontrolled runoff.

Hillside Drainage

Water is the most common trigger for slope failure. Saturated soil weighs more and loses strength, which allows it to slide.

We design drainage systems that move water away from the slope and the foundation. Typical components include:

  • French drains to collect subsurface water
  • Subdrains behind retaining walls to relieve pressure
  • Area drains and catch basins for surface runoff
  • Downspout tie-ins that route roof water to an approved outlet
  • Swales and brow ditches that redirect flow across the slope

Outlets must discharge to the street, a storm drain, or another approved location. Releasing water onto the slope face can cause the erosion the system is meant to prevent.

WHAT WE OFFER

Commercial Landslide Repair and Slope Failure Solutions

Commercial properties, private roads, and active construction sites on the Peninsula need slope repairs that keep access open, protect adjacent structures, and meet San Mateo County permitting requirements. We handle road and driveway failures, grading, debris removal, temporary shoring, and engineered slope rebuilding for property managers, HOAs, developers, and business owners.

Road and Driveway Landslide Repair

A failing road or driveway often shows cracks parallel to the slope edge, sagging pavement, or a shoulder that drops away after heavy rain. On the Peninsula, these failures are common on private roads in coastal hills where saturated clay soils lose strength.

We start by identifying whether the problem is surface erosion or a deeper slide. That distinction determines the repair method.

Common solutions we use include:

  • Soldier pile and lagging walls to support the downhill edge of the roadway
  • Soil nails or tiebacks anchored into stable material
  • Subsurface drains to lower groundwater beneath the road
  • Rebuilt base and pavement once the slope is stabilized

Where possible, we phase the work so at least one lane stays open for residents, tenants, or emergency vehicles.

Hillside Grading

Grading reshapes a slope to reduce driving forces and direct water away from vulnerable areas. On commercial sites, it is often required before new construction or after a slide has left an unstable vertical slope edge.

We follow the grading plan and specifications prepared by the project's geotechnical engineer. Typical tasks include:

  • Benching and keying Purpose: Ties new fill into firm native soil
  • Slope flattening Purpose: Lowers the angle to improve stability
  • Compacted fill placement Purpose: Builds slopes in controlled lifts
  • Surface drainage shaping Purpose: Directs runoff to swales and inlets

Landslide Debris Removal

After a slope fails, displaced soil, rock, and vegetation can block roads, bury parking areas, or press against building walls. Removing it safely matters as much as removing it quickly.

Debris removal should not begin until the remaining slope has been assessed. Taking material from the toe of an active slide can remove support and trigger further movement.

Our process typically follows these steps:

  1. Evaluate the slide area for ongoing movement
  2. Establish safe work zones and access for equipment
  3. Remove debris in stages, starting from stable ground
  4. Haul material off-site or stockpile suitable soil for reuse
  5. Install temporary erosion control on exposed surfaces

We coordinate with property owners and, when needed, with utility providers if lines have been damaged or buried.

Excavation Shoring

Deep excavations on sloped commercial lots can destabilize nearby foundations, streets, and utilities. Shoring holds the excavation walls in place while foundations, retaining walls, or drainage systems are built.

The right system depends on excavation depth, soil type, groundwater, and the distance to neighboring structures. Options we install include:

  • Soldier piles with timber or concrete lagging
  • Shotcrete walls with soil nails
  • Tieback anchors for deeper cuts
  • Sheet piling where groundwater is high

Shoring is designed by a licensed engineer and must comply with Cal/OSHA excavation standards. We monitor the walls during construction and report any movement to the design team so adjustments can be made before problems develop.

WHAT WE OFFER

Geotechnical Engineering and Specialty Slope Stabilization Services

Every landslide repair we perform starts with subsurface data, moves through a site-specific engineered design, and is backed by instruments that track how the slope behaves over time. For steep cuts and failing hillsides on the Peninsula, soil nailing gives us a way to reinforce ground in place where space is tight.

Geotechnical Investigation

Every repair strategy is built on reliable subsurface data. Our site investigations determine soil composition, underground water movement, and the exact depth of the slide plane.

Our investigation process typically includes:

  • Exploratory Borings Drilled using standard or compact rigs to retrieve deep soil and rock core samples.
  • Test Pits Excavated to evaluate shallow soil strata and existing fill layers.
  • Laboratory Soil Testing Assessing soil strength, expansion characteristics, and moisture limits under saturated conditions.
  • Groundwater Tracking Locating trapped water pockets and active subsurface seepage paths.
  • Geologic Mapping Identifying bedrock depth, fault fractures, and historical slide patterns.

Engineered Slope Repair Design

Computerized slope stability modeling calculates safety factors for existing conditions and verifies proposed repair methods. We use geotechnical findings to address the root cause of slope failure, not just surface symptoms. Here are the most common ways we do it:

  • Soldier Pile & Lagging Walls Retaining deep, unstable soil above or below structures.
  • Drilled Piers & Grade Beams Anchoring building foundations through weak soil into solid bedrock.
  • Tieback & Ground Anchors Providing structural pull-back resistance for walls and pile systems.
  • Subdrains & Horizontal Drains Relieving internal water pressure and lowering groundwater tables.
  • Keyed Buttress Fills & Regrading Rebuilding failed slope faces with engineered, multi-lift compacted fill.
  • Subsurface Slope Monitoring Before we build a custom fix, we need to keep a close eye on restless hillsides, and even after our work is finished, regular check-ups ensure everything stays secure.

Subsurface Slope Monitoring

Before we build a custom fix, we need to keep a close eye on restless hillsides, and even after our work is finished, regular check-ups ensure everything stays secure. 

We set up a smart network of advanced tracking tools, such as deep underground sensors, to catch shifting earth early.

We also do specialized meters to watch hidden water pressure, surface markers to track the top of the slope, and precision gauges to watch for any tiny movements in your walls or foundation.

When heavy winter rains raise the stakes, we ramp up our checks so you never have to guess. You get clear, straightforward reports that reveal long-term trends, giving you total peace of mind and helping you make the smartest safety decisions for your home.

Soil Nailing & Shotcrete Walls

Soil nailing reinforces an existing slope or excavation in place. Our crew drills angled borings into firm soil, inserts steel reinforcing bars, and pressure-grouts each hole. A steel-reinforced shotcrete (spray-applied concrete) face ties the nail matrix together.

Key Advantages for Peninsula Properties:

  • Minimal Site Excavation Requires significantly less earth movement than traditional retaining walls.
  • Limited-Access Capability Compact drill rigs operate easily on narrow lots and steep driveways.
  • Top-Down Construction Secures the slope in stages, preventing large exposures of unsupported dirt.
  • Aesthetic Customization Shotcrete facings can be sculpted and stained to match natural rock terrain.

Why Hillsides Slide on the Peninsula and How to Stop It

Most slope failures on the Peninsula start with water. Long-duration atmospheric river storms soak hillside soils for days, which raises water pressure in the ground and reduces the soil's strength.

Local geology adds to the risk. Many neighborhoods sit on weathered Franciscan Complex bedrock and clay-rich soils that weaken when wet and shrink when dry. Steep grades, seismic activity near the San Andreas Fault, and coastal bluff erosion in areas like Pacifica also contribute.

Human changes matter too. Cut slopes, added fill, and poorly routed downspouts can concentrate water where a hillside cannot handle it. Some of these problems take years to show up.

Common Cause
What We Typically Recommend
Saturated soil from heavy rain

Subsurface drains, French drains, and horizontal drains

Weak or shallow soils

Soil nails, retaining walls, or regrading

Undermined foundations

Drilled piers and grade beams anchored in stable material

Surface erosion

Erosion control matting, vegetation, and lined swales

Uncontrolled roof and yard runoff

Redirected downspouts and solid drain lines to approved outlets

We start every project with a site evaluation, and we coordinate with geotechnical engineers when a slope requires testing or a formal report. The right fix depends on the soil, the slope, and the water.

You can reduce risk before the rainy season by checking for these warning signs:

  • New cracks in walls, driveways, or soil
  • Doors and windows that start sticking
  • Leaning fences, trees, or retaining walls
  • Water seeping from a slope after storms end

Our 6-Step Landslide Repair Process: From Inspection to Final Fix

Every repair follows a strict engineering sequence, from initial assessment to structural construction and ongoing site monitoring, to solve the root cause of slope instability.

Initial Site Inspection & Damage Assessment

We perform an on-site property evaluation to inspect ground movement, foundation cracks, leaning walls, and active water seepage. Our team maps site elevations and assesses narrow Peninsula access points to establish baseline engineering data.

Subsurface Geotechnical Investigation

To identify the precise slide plane, we coordinate subsurface testing with licensed geotechnical engineers. Using soil borings, lab analysis, and groundwater tracking, engineers run stability calculations for heavy rain and seismic conditions.

Engineered Plan, Permitting & Itemized Proposal

We develop a custom repair design and manage permit submittals directly with San Mateo County or local municipal building departments. You receive a clear, itemized proposal detailing scope, materials, equipment fees, and project timelines.

Structural Slope Stabilization & Construction

Upon permit approval, our crew deploys specialized rigs to execute deep structural repairs. Depending on your site plan, we drill soldier piles into bedrock, install concrete piers, anchor soil nails, or rebuild slopes with geogrid reinforcement.

Drainage System Installation & Final Inspection

Because water triggers slope failure, we install subsurface French drains, wall subdrains, and surface V-ditches routed to approved outlets. Local building inspectors and project engineers conduct a joint walk-through to sign off and close permits.

Post-Construction Monitoring & Maintenance

We offer post-storm site checks to inspect drain outlets, monitor soil settlement, and verify wall alignment. High-risk slopes utilize inclinometer tracking alongside simple preventive guidelines to keep your property protected year-round.

Talk to an Expert

Cost of Landslide Repair in the Peninsula


Slope repair costs on the Peninsula typically range from $5,000 to $30,000 for minor drainage and erosion control, while major structural slope stabilization generally ranges from $50,000 to $500,000 or more. The exact price depends on the slope's size, soil and bedrock conditions, site access, and permit requirements.

Factors That Affect the Price

Every slope failure is different. We base each estimate on a geotechnical report and a site visit, not a flat rate.

The main cost drivers include:

  • Slope height and failure depth: Deeper slides need longer piers, tiebacks, or soil nails.
  • Soil and bedrock type: Expansive clay and weathered Franciscan rock, common in San Mateo County, often require more extensive design.
  • Site access: Narrow hillside lots may require small equipment, hand work, or cranes.
  • Groundwater: Subsurface water usually adds drainage work such as horizontal drains or subdrains.
  • Permits and engineering: Grading permits, geotechnical reports, and structural plans can add $5,000 to $40,000.

Proximity to a home or road also matters. Work near an existing foundation requires more shoring and monitoring.

Typical Cost Ranges by Service

The figures below are general ranges for residential projects in the Bay Area. Your final cost will depend on your engineer's design.


Geotechnical investigation and report: $4,000 – $15,000

Surface drainage and erosion control: $5,000 – $30,000

Subdrains or horizontal drains: $10,000 – $60,000

Retaining wall (per linear foot): $300 – $1,500+

Soil nail or tieback wall: $75,000 – $400,000+

Caisson or pier foundation support: $50,000 – $300,000+

Full slope rebuild with grading: $100,000–$500,000+

Smaller drainage fixes can prevent larger failures. We often recommend addressing water control first when the slope has not moved significantly.

Insurance, Financing, and Emergency Funding Options

Most standard homeowners policies exclude landslides and earth movement. California Earthquake Authority policies cover damage caused by an earthquake but generally not landslides triggered by rain. Review your policy's exclusions before work begins.

Common ways property owners pay for repairs include

  1. Home equity loans or HELOCs: These often offer lower interest rates than personal loans.
  2. SBA disaster loans: Available to homeowners after a federal disaster declaration, with long repayment terms.
  3. FEMA Individual Assistance: Limited grants may be available after a declared disaster.
  4. Shared costs with neighbors or HOAs: Slides that cross property lines may be split among owners.



Why Property Owners in the Peninsula Trust Us With Their Hillside

Hillside repair requires verified credentials, sound engineering, and a clear scope of work before any equipment arrives. We combine licensed crews, geotechnical expertise, written pricing, and prompt storm response so you know who is working on your slope and what they are doing.

Licensed, Bonded, and Insured Contractors

We carry full coverage to protect your property throughout every stage of construction, including a CSLB-required contractor's bond, general liability insurance for property damage, and workers' compensation insurance for every crew member on site.

In-House Engineering and Geotechnical Partners

Our project team collaborates directly with licensed geotechnical, civil, and structural engineers to deliver fully compliant site solutions. Their work includes conducting soil borings for subsurface testing, performing slope stability calculations, designing custom caissons, retaining walls, soil nails, or drainage systems, and preparing stamped plans for city and county permit approval.

Experience With Complex Hillside Sites

Our crews regularly navigate tight, limited-access sites using compact equipment and hand tools on narrow driveways or rear slopes. We specialize in stabilizing properties with active slide history, multilevel stilt foundations, and failed retaining walls that require safe removal before structural rebuilding.

Fast Emergency Response After Storms

Following a storm, our team provides rapid site assessments to detect fresh ground cracking, settlement, and active soil movement. We install temporary emergency stabilization, including plastic sheeting, sandbag berms, surface water diversion, and structural shoring for threatened homes.

Hillside Permits and Engineering Requirements

Most landslide and slope repairs on the Peninsula need permits before work can begin. Requirements vary by city and by San Mateo County, so we review the rules that apply to your property early in the process.

A permit is usually required for:

  • Excavation or fill above the local volume threshold
  • Work on steep slopes or in mapped landslide hazard zones
  • Retaining walls above a certain height or that support a slope
  • Changes to drainage patterns that affect neighboring properties

Some small repairs may not need a permit. Your local building or planning department makes the final determination.

Document
Prepared By
Purpose
Geotechnical (soils) report

Licensed geotechnical engineer

Identifies soil conditions and slope stability

Grading and drainage plan

Civil engineer

Shows cuts, fills, slope ratios, and water flow

Structural calculations

Structural engineer

Supports retaining walls, piers, and foundations

Erosion control plan

Engineer or contractor

Limits sediment runoff during construction

Review times depend on the jurisdiction and the size of the project. Hillside projects often take longer than flat-lot work because more than one department may review the plans.

We coordinate with engineers and permit offices so you do not have to manage each step yourself. Our team schedules required inspections and keeps documentation organized for final sign-off.

Permit rules can change, so we confirm current requirements for each project before construction starts.

Check Us Out In These Areas!

Our team provides professional landslide repair and geotechnical engineering services in:

San Mateo

Redwood City

Palo Alto

Burlingame

Hillsborough

Atherton

Menlo Park

San Carlos

Half Moon Bay

Don't see your specific neighborhood or hillside community on the list? We service properties throughout the entire San Francisco Peninsula and coastal corridor.

Contact our team today to discuss your site's geotechnical needs and confirm coverage for your location.

Talk to an Expert

WHAT OUR CLIENTS SAY

Testimonials

“They did a great job overall! It turned out that there was more damage than initially expected, so the project plan had to be revised from the original plan. However, Gregory made a revised plan, and we ended up finishing on schedule. He was also great about letting me know when the workers would be there and when they needed me home to discuss any decisions. I also appreciate how clean and organized they kept the worksite, since we were living there during the construction. The workmanship is fantastic; no issues with the work overall. Any issues I had were addressed by Gregory or his Foreman, to make sure that I was satisfied. I would definitely recommend the team, and will use them for future projects as well.”

a woman with blonde hair

Margaret Juergens

South San Francisco

“Greg Rocha has been the contractor for two intermediate-sized renovations. His work was excellent. The quality was high and the estimated budget reasonable. The work was completed on time and within budget to our complete satisfaction. We recommend Greg Rocha and his company highly.”

a man and a woman standing next to each other
Rhoda & Juhani Linna

San Carlos

“Thanks again for a great job. I will be happy to refer anyone who needs construction to you. P.s. You left the job site perfectly. I would never have known you were there!”

man in grey blazer near green trees during daytime

Patty Gerard

Half Moon Bay

“Peninsula Landslide Repair is extremely professional and attentive to the specific needs of the project. They are very clear in their communications and respectful of our house and our schedules. We received fantastic value for our money – they are worth every penny. We will certainly be recommending them to all our friends and family.”

A smiling couple stands together outdoors in autumn

Scott & Kathy Dewar

Moss Beach

FAQs About Landslide Repair in California

Who should I call for emergency landslide stabilization on the San Francisco Peninsula?

We provide rapid-response emergency stabilization and structural shoring across the Peninsula to secure failing slopes and protect your home immediately

How do I know if my retaining wall is failing?

Look for leaning, severe cracking, or bulging soil behind the structure. We offer expert structural evaluations to determine whether you need tiebacks, soil nails, or a complete rebuild.

Are your engineering methods designed for steep or tight lots?

Yes. We specialize in restricted-access engineering, using compact drill rigs and top-down construction methods tailored specifically for narrow lots and steep driveways.

What are the key benefits of soil nailing and shotcrete walls?

Soil nailing requires minimal excavation, offers rapid installation, and features carved and architecturally stained shotcrete facings that blend naturally with rock terrain. We manage the entire build from start to finish.

Do you handle local permits and geotechnical surveys?

Absolutely. We will help you with the local municipal permit process, geotechnical borings, and engineering compliance to ensure your project meets all regional building codes.

How do I protect my foundation from shifting hillside soil?

Installing drilled piers, grade beams, and deep anchors secures your building through weak soil and into solid bedrock. We custom-engineer these foundational defenses for long-term stability.

Can you install drainage systems to prevent water-driven slides?

Yes. Proper water management is critical. We offer installation of advanced subdrains and horizontal drains to relieve internal water pressure and lower subsurface groundwater tables.

Do you offer long-term slope and structural monitoring?

We do. We use precision instruments, including inclinometers, piezometers, and structural crack gauges, to track ground movement and provide actionable safety reports.

How can I schedule a professional geotechnical evaluation?

Contact us today at 650-844-3807 to speak with our engineering specialists and book an on-site property assessment to secure your hillside investment.

How long does a typical hillside repair project take?

Timelines vary based on site complexity, but we utilize efficient top-down construction techniques to minimize neighborhood disruption and complete repairs safely.

Peninsula Landslide Repair

Protecting homes all across San Mateo and Santa Clara counties. We give your hillside property the solid backup it needs so you can rest easy.