Medina homes face occasional water seepage and damp basement issues due to seasonal rain and local soil conditions. Wet Basement Services provides permanent waterproofing, drainage, crawl space, and mold remediation solutions tailored for Medina properties. We have compiled data regarding Medinas soil profiles, elevation, rainfall and more.
1. Geology and Soil Conditions
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The surficial geology for many parcels in Medina is mapped as glacial deposits: e.g., the geotechnical report for a site on Evergreen Point Road (“2227 Evergreen Point Rd, Medina WA”) identifies subsurface units such as: “Vashon till (Qvt) … Vashon advance outwash (Qva) … pre-Fraser deposits (Qpf)”. MCC Meetings+2WSDOT+2
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Vashon till is an unsorted mixture of clay, silt, sand and gravel deposited directly under advancing glaciers. It tends to be dense to very dense. The report notes: “Vashon till (Qvt) consists of an unsorted mixture of clay, silt, sand and gravel … typically dense to very dense.” MCC Meetings
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Lower-lying areas appear to have colluvium or alluvium overlying these glacial till deposits: one site noted loose silty sand / sandy silt over pre-Fraser deposits. MCC Meetings
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Because of this geology:
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There are fine-grained soils (clay, silt) plus dense till that restricts drainage.
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Water infiltrating the ground may not easily percolate downward, leading to perched groundwater or lateral movement of water toward foundation walls.
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Also, Medina’s topography includes slopes descending to Lake Washington and variable grades, meaning subsurface flow paths may direct water toward lower elevations. The soil overlaying dense till might saturate and cause increased hydrostatic pressure.
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Summary: On Medina lots you often have a basement adjacent to soils that drain slowly (fine grained + dense glacial deposits) combined with topographic gradients toward lake or lower ground. This combination increases basement water intrusion risk.
2. Rainfall and Seasonal Moisture Load
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Medina has a marine-west-coast climate with a wet season. Data show: ~119 rainfall days per year. Weather U.S.+1
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Example: In January, there are ~11.8 days of rain in Medina. Weather U.S.
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Rainfall totals in some datasets for Medina show relatively lower amounts (~11.97″ = 304 mm annual?) according to one source. Weather U.S. However, this figure seems low relative to King County averages; other data (IDcide) place annual precipitation for the metro near ~40″. Idcide
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Even with moderate rainfall, the critical issue is soil saturation and runoff accumulation, especially during sustained wet periods. Because of the dense soils and restricted drainage (see section 1), moisture remains longer around foundations.
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Implication: The wet season in Medina means extended soil moisture and higher groundwater potential; dry summers mean less drying out of soils and potential for water to accumulate around basement walls.
3. Topography and Drainage Characteristics
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Medina’s elevation and terrain: Some data indicate average elevation ~43 m (≈141 ft) above sea level. Worldwide Elevation Map Finder+1
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Topographic map data show elevations in Medina range from near sea/lake level up to ~163 m (≈535 ft) in some parts. Topographic maps
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The slopes toward Lake Washington and the presence of hills mean that surface runoff and subsurface groundwater movement may favor lower-lying lots and basements when drainage is not adequate.
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The city of Medina’s “Critical Areas” documentation lists erosion hazard areas, landslide hazard areas and geologically hazardous soils – which indicates underlying terrain/soil/drainage risk factors. Medina Washington+1
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Also, the city’s stormwater management pages emphasize runoff from paved areas, roofs and slopes as key concerns. Medina Washington+1
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In short: Basement water risk is higher in Medina when you have a lot grade that slopes toward the house, saturated soils uphill, or where drainage systems are not sufficiently diverting water away.
4. Combined Effect on Basement Water Risk
Putting the above together, here is how the risk typically plays out in Medina:
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A home with a basement is built in Medina on lot whose underlying soils include glacial till, silt/clay, with slow drainage.
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During the wet season, rain and surface runoff increase soil moisture. Because drainage is impeded, water builds up in the soil around foundations.
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Topography may channel either surface water or subsurface flow toward the lower elevation where the house sits, increasing hydrostatic lateral pressure against basement walls or upward pressure under slabs.
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The combination of saturated soils, slow percolation, and slope/runoff factors means basements are vulnerable unless properly waterproofed and graded.
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If landscaping, turf installation or water-features near the home raise the grade, reduce drainage, or retain water next to the foundation, you exacerbate the risk.
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Additionally, because Medina identifies geologically hazardous soils/erosion zones, some lots may have unseen water flow paths or soil movement that further complicates waterproofing.
Medina basements often experience seepage through foundation walls and floors. We install:
- Interior French drains
- Vertical drain wall membrane
- Sump pumps and battery backups
- Exterior drainage solutions
Medina homes often deal with:
- Water seepage during heavy rain
- Standing water from seepage in cold joints
- Damp walls and floors
- Musty odors
- Mold growth on wooden framing
✔ Local Medina basement waterproofing specialists
✔ Permanent water intrusion and mold solutions and warranties
✔ Certified mold remediation experts
✔ Quick response for emergency leaks
Serving all neighborhoods in Medina, WA
Request a free waterproofing estimate today.