Lot Grading Maintenance

Rain Barrels 

Rain Barrels should have an overflow outlet that will discharge water to a location that is past the excavation zone (approx. 4.5 m or 15 ft.). Watering plants and shrubs in this zone should be limited to the minimum amount required to sustain the plants. 

Window Wells 

Window wells are installed to accommodate foundation grading that ensures positive slope away from the home. Positive foundation drainage (draining away from the building foundation) is the most important defense against water entering the basement. Ideally, water does not enter window well openings. However, water that does enter the window well should flow down the drain tile, installed at the time of construction, to the weeping tile system. Window wells should be kept free of debris or leaves to ensure that water can enter the drain tile and flow to the weeping tile. 

Eavestroughs and Downspouts 

Stormwater collected by the eavestroughs is channeled to the ground through the downspouts. This results in a substantial concentration of flow at the discharge points. To protect your home as well as your neighbours’ homes, downspout extension pipes should project past the excavation zone by approximately 1.2 meters. The excavation zone is typically 4.5 m (15 ft.) outside of your foundation walls. Eavestoughs should be cleaned and inspected regularly to ensure unrestricted water movement with no overflow. Downspout extensions pipes minimize foundation zone saturation which increases the risk of water entering the basement (infiltration flooding), or frost heaving the sidewalks, driveways and decks. See diagram D. 

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Swales are shallow, sloped channels that move stormwater and underground water to a public right-of-way. Typically, property line swales are shared by adjacent properties and serve to provide surface drainage for both lots. See Diagram E. Internal swales may also be present on the lot and must be maintained if needed. See Diagram F. 

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Settlement or Blockages 

Settlement or blockages in drainage swales become obvious during rain events but are relatively easy to fix with the addition of soil or removal of a blockage. Consultation with adjacent property owners is advised when considering repairs to a common property line swale. 

Maintenance Checklist 

The maintenance inspection should include all aspects of surface drainage and any potential impact on adjacent properties. 

  • Downspouts discharge to the ground surface past the excavation zone and within the property. 
  • Positive slope exists away from the foundation walls. See Diagram D (page 13). 
  • Drainage swales convey surface drainage off the lot without impacting adjacent properties. See Diagram F  and rear to Front Drainage Design for typical examples. 
  • Settlement under steps or decks are properly backfilled. 
  • Window wells are debris free to ensure efficient drainage. 

Property Insurance 

Generally speaking, damages caused by overall flooding or infiltration through cracks are not insurable.