Coastal Property Owner Slope Drainage Checklist

Slope Characteristics

Slope Height:

• less than 10 feet
• 10 to 50 feet
• greater than 50 feet

Slope Angle:

____ degrees (see discussion in Slope Stabilization and Erosion Control Using Vegetation)

Slope Vegetation:

• bare soil areas
• vegetation cut, removed or cleared
• mature vegetation (trees, shrubs and ground cover)
• water loving plants (horsetail, skunk cabbage, willow, salmonberry, etc.)

Slope Geology:

• sand or sand and gravel
• glacial till
• silt/clay
• rock

Landslide Indicators:

• recent slide
• bowl-shaped slope configuration
• hummocky ground
• leaning trees or bowed trunks
• areas of low brush (blackberry)/bare areas

Coastal Zone Atlas:

• landslide area
• unstable
• intermediate stability
• stable

Beach Access:

• stairs
• wide path/road
• tram
• narrow path

Site Groundwater

Groundwater Observation:

• seepage on slope: crest, face, or toe?
• wet soil zone: crest, face, or toe?
• vegetation indications of wet soil: crest, face, or toe?

Location of observed groundwater:

• Near-surface soil seepage 1 to 3 feet below crest of slope
• Groundwater seepage 5 to 10 feet below crest of slope
• Groundwater seepage on slope face more than 10 feet below crest or at slope toe

Site Surface Water

Surface Water Features:

• stream channel
  
• ponds/wetlands
  how far from crest of slope?__________
  
• flows down/over the slope
  
• tightline down slope
  
• erosion evidence: rills, gulleys, etc.

Surface Water/Storm Water Flows

• Sheet flow from:
  
  • driveway
    
  • parking area
    
  • lawn
    
  • other
• Roof downspouts empty:
  
  • onto ground
    
  • into buried pipe
    
  • other
• Outlet for downspout pipe:
  
  • into soil or on surface of slope
    
  • tightlined down slope
    
  • unknown (test with hose)
• Other pipe/culvert discharges:
  
  • onto slope
    
  • tightlined down slope
    
  • other
• Areas where surface water disappears into ground?
  • Yes
  • No
• Seepage/water noticed along beach access path?
  • Yes
  • No

Other Site Features

Location of:

• Septic system
  • between house and slope
  • behind house
  • N/A
• Irrigation system
  • any leaks
  • summer use only
  • control valve off and lines drained in winter
• Downspout infiltration system
  • between house and slope
  • behind house
  • not applicable
• Landscape yard drains
  • tightline down slope
  • discharge onto slope
  • unknown (test to find out)
• Landscape pools/ponds/fountains
  • between house and slope
  • behind house
  • not applicable
• Hot tub(s)/swimming pool(s)
  • between house and slope
  • behind house
  • not applicable
• Where are tub/pool/pond/fountains drained?
  • Into a tightline drainage system
  • onto slope
  • below slope
  • onto ground
  • unknown (test to find out)

Distance of site features from slope crest:
 

Other resources:
Have you reviewed other information from Ecology in this website series to help you?
(See links section for more information)