# iMOD User Manual version 5.2 (html)

#### 12.19DRN Drainage package

The drainage package defines the location, the elevation (L) and the conductance (L${}^{2}$/T) of the drainage system by two IDFs. The drainage system represents drainage pipes and drainage ditches by which water is removed from the model when the calculated head in a modellayer exceeds the elevation of the drainage system. The drainage package is usually connected to the first modellayer only. The DRN package is comparable to the DRN package of MODFLOW.

Drainage simulated in cells with surface water becomes inactive when the drainage elevation is below the water level in the same cell as defined in the RIV package. Herefor it is necessary to set the parameter ICONCHK=1 in the runfile.