The Newton Solver (NWT) package can only be used in MODFLOW-NWT. It can only be used with the Upstream Weighting UPW) package. When the Upstream Weighting package is used, the Newton Solver package must be used. The pane for this package is on the MODFLOW Packages and Programs dialog box under Solvers.
The Newton Solver has a large number of possible parameters.For that reason, several different tabs are used to hold the controls used to set those options. However, initially only one tab is visible. The others will appear if they are needed.
The options that are always required are on the Basic Options tab.
The options that are required if Options is set to "Specified" are on the Additional Options tab.
The options that are required if Options is set to "Specified" and LINMETH is set to GMRES are on the GMRES Variables tab.
The options that are required if Options is set to "Specified" and LINMETH is set to Chi MD are on the Chi MD Variables tab.
When the Well package in MODFLOW-NWT is used, a warning similar to the following will always be printed to the listing file.
NEGATIVE PUMPING RATES WILL BE REDUCED IF HEAD
FALLS WITHIN THE INTERVAL PHIRAMP TIMES THE CELL
THICKNESS. THE VALUE SPECIFIED FOR PHIRAMP IS 0.10000E+00
WELLS WITH REDUCED PUMPING WILL BE REPORTED TO FILE UNIT NUMBER 141
