New Mexico - Texas Water Commission BESTSM/MODFLOW Linked Model Readme.doc 2/9/99 The files and data contained in these folders was prepared by Boyle Engineering Corporation at the request of the New Mexico - Texas Water Commission and is being provided for your use. These files supercede all previous versions and are not to be used in combination with any previous simulations including alternatives. This version incorporates the following significant changes in model structure: * The model provides the ability to allocate water in equal priority in attempting to satisfy agricultural and municipal demands. This process may require iterative application to achieve equal priority allocation. * The model will accept a variable (by year) irrigation application rate. * The model represents drain flow quality using the following generalized relationship: quality = a * flow^b, where a and b are constants. These changes, along with a few minor refinements to the pre- and post- processors, have been incorporated in this updated version of the linked model. In addition, the current version incorporates a noteworthy change in input data. This change involves the use of Franklin Canal flows in 1990 to represent diversions by the American Canal. This change was to account for disruptions in normal diversion operations in 1990 due to a diesel fuel spill into the river. Please copy the folder of files to your hard drive. Prior to running the model, please change all the attributes from read-only either by selecting all files in the Windows Explorer, selecting Properties, and deleting the check in the Read- Only attribute box or by issuing the DOS command attrib -r *.*. You must do this for all directories and subdirectories. The CALIB directory contains the files required to run the New Mexico-Texas Water Commission Rio Grande model calibration simulation. The MODFLOW subdirectory contains the files required to run the MODFLOW portion of the model. The Calibration run begins by running MODFLOW with the BESTOUT.DAT. This file contains the historical flows for the Rio Grande above Leasburg, Leasburg Canal, Eastside Canal and Westside Canal. MODFLOW execution begins by running PREMAIN.EXE. The required responses are: 1 (Historic simulation) 11 (Beginning month of the non-irrigation season) 2 (Ending month of the non-irrigation season) 3 (Beginning month of the irrigation season) 10 (Ending month of the irrigation season) 26 (% of headgate diversion lost in canals) Once PREMAIN has been executed, type RUNMOD to execute the batch file that runs MODFLOW. When this is complete, execute POSTMAIN. The responses required for the prompts are identical to the first five prompts listed for PREMAIN. POSTMAIN creates a new file called EPIMPWTR.DAT. This file must be copied to the CALIB directory and renamed RGIMPWTR.CAL. BESTSM is executed from the CALIB directory by typing BESTSM7. The baseline directory contains the "baseline" scenario. This scenario has been developed for comparative purposes only, and is not necessarily representative of the baseline scenario to be defined during the N.E.P.A. process. The baseline scenario provided here assumes that daily agricultural demand distribution can be represented using the average daily demand distribution for the years 1990- 1995. Annual demands are taken to be the historical annual demands. All facilities are assumed to be in place at the start of the simulation. Reservoir levels for the start of the simulation are set equal to levels observed on September 30, 1995. No provision has been included in this scenario for meeting any forecasted growth in demands which might otherwise have been met with the water treatment plants contemplated as part of the El Paso - Las Cruces Regional Sustainable Water Project. Note that Franklin demands have been substituted for American canal demands. This is to account for the American Canal extension and the elimination of Wasteway No. 1 and Ascarate returns. In contrast to the calibration simulation, the baseline simulation is begun by executing BESTSM, to create a set of forecast flows needed by MODFLOW. Please note the first response in executing Premain is "0" for selection of forecasting mode. For more detailed instructions on model execution, consult the BESTSM Documentation and User's Manual dated April 1998, Section 5.2.