Theo

Good day Sean, Thank you for you reply. Maybe my approach is wrong!? The open pit areas will be backfilled after mine development and therefore I still need to give a representative hydraulic conductivity (e.g. 0.5m/d) to the excavated areas (backfilled). So, the recovered groundwater level "recovers" to the 'initial stage' as set in the LAK package. It would have been great if the 'initial stage' in the LAK package could be set according to a TIN. The problem is that the "model" I am working with has very high topography. The pits are located in the top and sloped parts of mountainous areas. (as seen in the attachment). Therefore, using an initial stage "recovers" the groundwater level far above certain regions in my model (causing flooding). So my main objective is to get an idea on how long it will take the groundwater to recover to calibrated conditions (transient). So rather let me ask: How can I approach this? Is there any other way I can model recovery of groundwater levels? (even if it means starting from scratch) (I attached updated figures). Any input will be much appreciated.

Good day GMS community and other. So am I modelling a typical open pit mine scenario, however I am struggling to model groundwater recovery (rebound) to natural (calibrated head) conditions. - please see attachment. I did the follow steps using GMS 9. 1. Developed conceptual model; 2. Used drain package to represent the bottom of the open pits; 3. Calculated (using zone id's) pit inflows; 4. Modelled the groundwater level during mining (Life of Mine). Thus bottom of the open pits represents my post mine heads. My objective is to calculate how long the groundwater level (post mine head) will take to reach natural conditions (calibrated head). My problem is as follow: 1. I can't use the Lake Package as this requires an initial stage. In my scenario (please see attachment) the groundwater level change throughout my open pit area. Using an initial stage (in the Lake package) model the groundwater level to the initial stage therefore flooding my whole model domain. Is there a way to model groundwater recovery? How can I calculate how long it will take to reach the calibrated conditions? Hope to hear from you soon. Regards, Theo (Hydrogeologist)

HI Alan, Thanks for the reply. My main problem was my recharge input data - as it is a transient model the required data should be transient as well (obviously) Cheers, Theo

Dear All, I am struggling to figure out why my flow budget is not tabulating recharge as a "Flow In" value. Background: So I competed a steady state groundwater flow model, using NWT solver in GMS 8.3. The steady state flow model works perfectly (i.e.. flow budget shows a value as "flow in" for recharge, calibrated, heads, etc.) However, as soon as I change the steady state groundwater flow model to a transient model, using transient observation data, no value is "read" in the flow budget for recharge. So i played around to sort this out, using transient recharge data or single value recharge data. In the modflow package the recharge values are shown. All my dates/times for the stress periods, observation data and recharge are the same. So my question is what should I do to get the recharge "read" by modflow to be tabulated in the flow budget? Without the recharge value forming part of my modflow solution the observation heads can't be calibrated using transient data. Any suggestions will be great. Thanks in advance. Cheers, Theo