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→Spacing drainage pipes to reduce groundwater mounding
Line 29:
Line 29:
may be simplified to:
may be simplified to:
<math>Drain\ spacing=\sqrt{\frac{4K_{media}\left(D_{d}-D_{w}\right)^{2}}{q}}</math>
<math>Drain\ spacing=\sqrt{\frac{4K_{media}\left(D_{d}-D_{w}\right)^{2}}{q}}</math>
−Where:
+{{Plainlist|1=Where:
−''K<sub>media</sub> is expressed in m/day
+*''K<sub>media</sub> is expressed in m/day
−''D<sub>d</sub>'' is the depth to the drain pipe (m)
+*''D<sub>d</sub>'' is the depth to the drain pipe (m)
−''D<sub>w</sub>'' is the minimum acceptable depth to the water table during infiltration event
+*''D<sub>w</sub>'' is the minimum acceptable depth to the water table during infiltration event
−''q'' is the inflow volume expressed as a depth over the entire surface (m)
+*''q'' is the inflow volume expressed as a depth over the entire surface (m)}}
+===Example===
===Example===
During a 25 mm storm event, a bioretention cell receives concentrated flow from a catchment 20 times larger than its own footprint (25 x 20 = 500 mm = 0.5 m).
During a 25 mm storm event, a bioretention cell receives concentrated flow from a catchment 20 times larger than its own footprint (25 x 20 = 500 mm = 0.5 m).