California Prepares for Heavy Rainfall as Strong El Niño Approaches: Are We Ready to Face the Storms?

California Faces Strong El Niño: Are Buildings Prepared?

As the National Oceanic and Atmospheric Administration (NOAA) forecasts a wetter-than-average winter owing to a strong El Niño, California is gearing up for potential heavy rainfall that could exacerbate serious drainage issues. The implications for infrastructure are significant, especially concerning foundations, retaining walls, and slopes.

Kyle Tourjé, Executive Vice President of Alpha Structural, emphasizes the gravity of the approaching winter conditions, highlighting that repeated storms could intensify existing problems such as soil erosion and structural weaknesses. "As the winter progresses, saturated soil from storms can increase pressure on retaining walls and exacerbate cracks in foundations that may have already shown signs of distress," he explains.

Preparing for the Rain

For property managers and homeowners throughout California, preparation should go beyond simply planning for flood response. Evaluation of drainage systems, foundations, and retaining walls is crucial, particularly before the onset of repeated storms. A brief saturation from a single storm may be manageable, but continuous rain prevents the soil from drying out, keeping it saturated and at risk of further structural damage. According to Tourjé, “Each storm cycle can saturate deeper layers of soil, leading to the widening of cracks and accelerating ground movement.”

The way a building responds to persistent rainfall involves several factors such as foundation type, soil conditions, slope, drainage efficiency, and any prior repairs that have been implemented. "When soil becomes overly saturated, the added weight can worsen weaknesses in retaining walls and lead to foundation issues due to softened supporting soil," he adds.

Understanding Soil Saturation and Erosion Risks

During heavy rains—especially in an El Niño year—there is an increased risk of deep-seated landslides that can severely damage both buildings and public infrastructure. The U.S. Geological Survey has noted that such landslides are often triggered by prolonged periods of above-average rainfall.

Additionally, property owners should remain vigilant for signs of drainage issues that may go unnoticed during dryer times. Common problems include downspouts that direct water towards foundations, blocked drainage systems, and runoff from neighboring properties—all of which can lead to dangerous soil movement when saturation occurs.

Recognizing Warning Signs

Tourjé advises homeowners to observe current conditions on their properties as these can provide critical early warnings of future problems. Existing issues such as cracks, differential settlement, and movement in retaining walls can serve as indicators of how the property might react to heavy rainfall in the future. “Newly developing cracks or other symptoms like doors and windows sticking, sloping floors, or water accumulation around foundations are all behaviors that signal a structure struggling against prolonged rain,” he notes.

To have a clearer picture of evolving issues, he recommends documenting pre-storm conditions. Homeowners can take dated photographs, marking the locations and sizes of existing cracks to identify any changes that may occur during the storm season. Documentation of previous repairs or modifications to drainage systems is equally valuable, providing engineers with a frame of reference in determining whether observed movements are new or ongoing.

Proactive Measures for Property Stability

When heavy rains arrive, not all conditions demand the same mitigation responses. Engineers typically assess the locations of any required movements and the changes they undergo as the soil dries. Movements that improve after rain but worsen during storms may indicate drainage problems, while consistent movement could signal deeper issues with slope instability or foundational integrity.

The time to act is now, particularly with El Niño on the horizon. Unaddressed property conditions pose serious risks if not managed actively. As Tourjé emphasizes, unresolved drainage problems and signs of structural movement should not go overlooked: “Repeated storms can escalate these conditions into larger issues. If not taken seriously, erosion might worsen, cracks may expand, and wet soil could increase load on retaining walls, leading to more extensive damage overall.”

By pinpointing structural weaknesses and drainage issues before storms arrive, property owners will be positioned to determine when professional evaluations or repairs become essential.

About Alpha Structural, Inc.

Founded by Dave Tourje, Alpha Structural is a leading structural repair and engineering firm in Southern California, addressing geological challenges and structural vulnerabilities since the 1980s. With over 30 years of experience in foundation repair, hillside stabilization, and seismic retrofitting, Alpha Structural stands out by offering integrated in-house engineering and construction services, significantly reducing miscommunication and costs associated with typical projects.

For more detailed information about how to prepare your property for the upcoming storm season and the services provided by Alpha Structural, visit their website.