### 2.12.6.2. Water Balance[¶](#water-balance "Permalink to this headline")

The total water balance of the system is given by

(2.12.64)[¶](#equation-12-59 "Permalink to this equation")\\\[\\Delta W\_{sno} +\\sum \_{i=1}^{n\_{levsoi} }\\left(\\Delta w\_{liq,i} +\\Delta w\_{ice,i} \\right) =\\left(q\_{rain} +q\_{sno} -E\_{g} -q\_{rgwl} -q\_{snwcp,\\, ice} \\right)\\Delta t\\\]

where \\(W\_{sno}\\) (kg m\-2) is the total mass of snow (both liquid and ice, in resolved snow layers or bulk snow), \\(w\_{liq,i}\\) and \\(w\_{ice,i}\\) are the masses of water phases (kg m\-2) in soil layer _i_, \\(q\_{rain}\\) and \\(q\_{sno}\\) are the precipitation forcing from the atmosphere (kg m\-2 s\-1), \\(q\_{snwcp,\\, ice}\\) is the ice runoff associated with snow-capping (below), \\(E\_{g}\\) is the ground evaporation (section [2.12.4.2](#surface-flux-solution-lake)), and \\(n\_{levsoi}\\) is the number of hydrologically active soil layers (as opposed to dry bedrock layers).

