Notes

Outline

St. Andrews Church Basement Water Problem December14, 2008

What We Know There are two possible  causes of water: Ability to drain away downpours and heavy rain –    We have this problem Comes in through leaks around window areas Perhaps in other places High water table - We don’t believe we have this problem Test diggings did not detect water table 13 feet down

Main Runoff Area

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Elevation Plan

What We Have Done So Far Cleaned out Main Catch Basin Approximately 3 feet of sediment at the bottom restricting drainage into soil Catch basin can only absorb a fraction of design due to roots and silt Conducted soil permeability test – Schofield engineer Dug two test holes Measured ability of soil to absorb water (16 inches of water per hour) Looked for level of water table (none found down to -13 ft.) Good news Determined the volume of water that must be absorbed in a given time (2 yr, 10 yr, 25 yr and 100 yr storms per standard Framingham models) Assessed the current design – less than 1/6 of what is required Designed an upgrade to accommodate water from a 100 yr storm and be sustainable (with maintenance) for 50 years

Design Concept

Secondary Issue Gutters, Downspouts and Extensions Gutters generally OK (added gutters on front entry of Sanctuary) Downspouts OK Extensions Many are bent etc. - unsightly Require frequent repair Need to design out

Design Broken Into Five Phases

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Phases (cont.)

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Summary