As climate patterns shift, the Pacific Northwest faces increasing effects from atmospheric rivers—long, narrow corridors of concentrated moisture that bring heavy rainfall to coastal regions. While these weather events are crucial for replenishing water supplies, their intensity and frequency pose significant risks to homes situated on sandy soils next to the ocean. Properties surrounded by taller trees and increased tree canopy benefit immensely from natural protection and enhanced stormwater management.

Understanding Atmospheric Rivers

Atmospheric rivers are essential to the Earth’s climate system, delivering vital precipitation to the Pacific Northwest. According to the USDA Climate Hubs, these systems transport vast amounts of moisture from tropical regions, providing much-needed rain. However, when atmospheric rivers intensify due to climate change, they can lead to extreme weather events, resulting in flooding, erosion, and considerable structural damage.

In 2023, the Pacific Northwest faced significant challenges as atmospheric rivers unleashed heavy rainfall and intense winds, leading to widespread damage to coastal homes. These weather events, characterized by moisture-laden air streams, caused severe flooding and landslides, undermining foundations and eroding coastal bluffs. Many homeowners found their properties inundated, with water damage affecting interiors and electrical systems. The relentless waves, driven by strong storms, battered seawalls and piers, exacerbating the situation. Communities grappled with the dual threats of immediate repair costs and long-term resilience planning, as the impacts of climate change increasingly manifested in the region’s volatile weather patterns.

The Role of Trees in Coastal Resilience

Homes built on sandy soils face unique challenges, particularly when it comes to stability. The extensive root systems of taller trees help stabilize the soil, reducing erosion and improving water retention. Trees absorb excess rainwater, which mitigates flooding risks during heavy downpours. A robust tree canopy also acts as a windbreak, reducing the impact of strong winds that accompany storms.

Unfortunately, the foolishness of limiting tree heights to just 16 feet can severely degrade tree canopy and undermine the protective benefits trees provide. Topping trees, a practice that involves cutting back large branches, can lead to the death of the trees, further reducing their ability to absorb rainfall and prevent flooding. The loss of mature trees diminishes the ecosystem’s resilience, making homes even more vulnerable to the impacts of atmospheric rivers.

Increasing tree canopy growth through strategic planting is essential for enhancing these natural benefits. More trees create a resilient ecosystem that supports effective stormwater management, preventing potential damage that can escalate into the hundreds of thousands of dollars. Without adequate tree cover, homes are at increased risk of foundation damage and structural issues, including cracks in walls that result from shifting soil.

Risks for Homes on Hills

Hillside properties are particularly vulnerable during atmospheric river events. Saturated soil can lead to landslides and significant erosion. As climate change intensifies storms, the frequency and severity of rainfall events are expected to rise, increasing the risk of mudslides that threaten homes on slopes. Properties lacking adequate drainage systems or tree cover are at even greater risk, as soil stability diminishes, often resulting in substantial foundation damage and costly repairs.

Stormwater Management Solutions

In areas with abundant trees, a diverse ecosystem contributes to effective stormwater management. However, in coastal regions where trees may be sparse, homeowners must implement engineered solutions. Strategies to enhance stormwater management include:

• Stormwater Drains: Properly designed drainage systems can redirect excess water away from vulnerable areas, minimizing the risk of erosion and flooding.
• Permeable Pavements: Utilizing materials that allow water to seep through can help manage runoff and prevent pooling around homes.

Protecting Building Materials

With a combination of natural tree protection and effective stormwater management, homes are better equipped to withstand the challenges posed by atmospheric rivers. Nevertheless, homeowners must remain vigilant about maintenance. Continuous moisture from heavy rainfall can lead to:

• Mold and Mildew: High humidity levels create an environment conducive to mold growth, necessitating ongoing monitoring and maintenance.
• Wood Rot: Structural elements such as decks and siding are at risk if exposed to prolonged dampness, highlighting the importance of regular inspections and timely repairs.
• Cracks in Walls and Foundation Damage: Homes built on sandy soils are particularly susceptible to cracks and structural shifts due to water saturation, underscoring the need for careful monitoring and proactive repairs.

In the pursuit of preserving scenic views, advocating for aggressive tree removal practices or tree height restrictions, can lead to severe consequences for both the environment and their properties. This shortsighted approach not only compromises the natural beauty of the landscape but also significantly increases the vulnerability of homes situated on hillsides. Without the protective canopy and root systems of mature trees, these properties are at greater risk of damage from soil erosion, landslides, and flooding during heavy rainfall events. The potential costs of such damage can escalate into the tens of thousands of dollars in repairs for cracked foundations, structural instability, damaged siding and decks, damaged windows, frequent repainting and water damage. But these costs are also incurred by homeowners subject to tree height restrictions. The total cost to these homeowners due to increased maintenance costs could be in the millions. In addition the cumulative damage from the required repairs to make a home ready to sell will reduce the profits on the sale. Ultimately, the desire for an unobstructed view can come at a steep price, leaving homes exposed and defenseless against the very forces of nature that trees help to mitigate.

Conclusion

Atmospheric rivers are a critical part of the Pacific Northwest’s hydrology, but their increasing intensity due to climate change presents challenges for coastal homes, especially those on hillsides. Properties with robust trees and enhanced tree canopies benefit from natural protection against wind and improved stormwater management, reducing risks of flooding and erosion. Limiting tree heights and engaging in practices like topping not only degrades tree health but also diminishes essential protective benefits, increasing vulnerability to severe weather. Planting more trees is essential for building a resilient ecosystem that can absorb excess rainfall and prevent costly damage, potentially saving homeowners hundreds of thousands of dollars in repairs. By combining the resilience of nature with engineered solutions, homeowners can better safeguard their investments against the forces of extreme weather. Embracing both natural and proactive strategies is vital for creating lasting resilience in an evolving climate.