P8 Mass Balance Terms
Term Name Description
1 Inflows from Watershed sum of all tributary watersheds
2 Inflows from Upstream Devices sum of outflows from all upstream devices
3 Infiltration outflow passing through bottom/sides of device
4 Exfiltration net outflow to groundwater  = term 3 -  term 5
5 Filtration Removal particle mass removed during infiltration (trapped in soil)
6 Normal Outflow controlled by hydraulic properties of outlet or swale
7 Spillway / Overflow occurs at max elevation, controlled by water budget
8 Sedimentation / Decay settling or other removal mechanisms
9 Total Inflow sum of inflows  = term 1 +  2
10 Surface Outflow normal + spillway = term 6 + 7
11 Groundwater Outflow net outflow to groundwater = term 4
12 Total Outflow surface + groundwater = term 10 + 11
13 Total Trapped filtration + sedimentation = term 5 + 8
14 Storage Increase change in mass stored within device during time step
15 Mass Balance Check net mass balance error = term 9 - 12 - 15 - 14