Exfiltration is a term used by Hydrology Studio indicating flow exits the pond. It can be used interchangeably with infiltration. Exfiltration flows are based on the contour area at each stage or elevation.
Please note that exfiltration requires your pond to have contours. The Manual storage option does not provide contour inputs and therefore exfiltration flows will not be computed.
Exfiltration flows are computed using the following equation:
Where:
Qex = outflow (cfs)
ER = exfiltration (percolation) rate (in/hr)
SA = contour surface area at a particular stage (sqft)
When Exfiltration is the Only Outflow
If Exfiltration is the only outlet device in your pond, be sure the pond’s contours increase with increasing stage. That is, avoid specifying a pond with zero side slopes. The Stage vs. Q curve in your pond must have a forward slope in order to execute proper routing calculations.
Retention Pond Recovery in Shallow Aquifers
Looking to calculate mounding and recovery times (unsaturated and saturated) for retention ponds in shallow sandy aquifers? Check out Studio Express Groundwater feature.
