United States Army Corps of Engineers (USACE), United States Bureau of Reclamation (USBoR), United States Geological Survey (USGS), New Mexico Interstate Stream Commission (NMISC).


The Upper Rio Grande Water Operation Model (URGWOM) is a suite of tools developed cooperatively by water management agencies in New Mexico to better understand, predict, plan, and account for surface water movement through the Rio Grande system in New Mexico.  Included in this suite of tools are several daily timestep RiverWare models used to develop annual operating plans, track and account for water use by water type, and perform 10-year planning analysis.  However, the computational burden of the daily timestep models makes it difficult to evaluate a large range of potential scenarios or management options, or perform long term planning analysis.  In addition, the surface water system is impacted directly by the groundwater system, and both are affected by human demands.  Simulation of the connections between these systems is not comprehensive in the daily timestep surface water operations models.


A tool is needed to screen over a broad range of alternatives to identify leading candidates for further analysis with the daily timestep URGWOM tools, and include the long term interactions and feedbacks between the surface water, groundwater, and human demand systems for planning purposes.  URGSiM is a monthly timestep decision support simulation tool built in Powersim Studio.  URGSiM is based on surface water dynamics and reservoir operations from the URGWOM daily timestep models, groundwater dynamics based on three regional groundwater flow models, atmospheric demand based on the USBoR’s ETToolbox, and human demand based on historic water use and population growth trends modifiable by the model user.  The model has an easy-to-use graphic user interface, and runs 40-year scenarios in tens of seconds.  It has been used to screen 1000 different 100-year climate scenarios based on 400 years of tree ring data to choose three 10-year sequences for further analysis with the daily timestep URGWOM planning model.  Development in conjunction with the URGWOM technical team is ongoing.

Key Publications

Rio Grande Modeling:

Bureau of Reclamation, 2013. West-Wide Climate Risk Assessment: Upper Rio Grande Impact Assessment, December 2013. At

Roach, J. and V. Tidwell, A compartmental-spatial system dynamics approach to ground water modeling, Ground Water, 47(5), 686-698, 2009.

Water Leasing:

Broadbent C.D., D.S. Brookshire, D. Coursey and V. Tidwell, 2016. Futures contracts in water leasing: An experimental analysis using basin characteristics of the Rio Grande, NM, Environmental Resources Economics, on line, DOI 10.1007/s10640-016-0032-4

Broadbent, C.D., Brookshire, D.S., Coursey, D., Tidwell, V.C., 2014. An experimental analysis of water leasing markets focusing on the agricultural sector, Agricultural Water Management, 142, 88-98.

Broadbent, C.D., D.S. Brookshire, D. Coursey and V.C. Tidwell, Creating real time leasing market institutions: An integrated economic and hydrological methodology, Journal of Contemporary Water Research and Education, 144, 50-59, 2010.

Broadbent, C.D., D.S. Brookshire, D. Coursey and V.C. Tidwell, Water leasing: Evaluating temporary water rights transfers in New Mexico through experimental methods, Natural Resources Journal, 49(Summer-Fall), 707-741, 2010.

Coupled Natural and Human Systems:

Fernald, A., V. Tidwell, J. Rivera, S. Rodriguez, S. Guldan, C. Steele, C. Ochoa, B. Hurd, M. Ortiz, K. Boykin and A. Cibils, Modeling water, environment, livelihood and culture in traditional irrigation communities and their linked watersheds, Sustainability, 4(11), 2998-3022, 2012.

Fernald A.G.,S.Y. Cevik, C.G. Ochoa, V. C. Tidwell, J.P. King, and S.J. Guldan, River hydrograph retransmission functions of irrigated valley surface water-groundwater interactions, Journal of Irrigation and Drainage Engineering, 136(12) 823-835, 2010.

Weber, M.A., V.C. Tidwell and J.A. Thacher, Dynamic physical and economic modeling of riparian restoration options, Environmental Modelling and Software, 25(12), 1825-1836, 2010.

Collaborative Modeling:

Cockerill, K.C., V.C. Tidwell, L. Daniels and A. Sun, Engaging the public and decision makers in cooperative modeling for regional water management, Environmental Practice, 12(4), 316-327, December 2010.

Cockerill, K.C., L. Daniel, L.A. Malczynski, and V.C. Tidwell, Collaborative Modeling for More Effective Policy, Policy Sciences, 42(3), 211-225,  2009.

Tidwell, V.C. and Cors van den Brink, Cooperative modeling: Linking science, communication and ground water planning, Ground Water, 46(2), 174-182, 2008.

Cockerill, K.C., V.C. Tidwell, H. Passell, and L. Malczynski, Collaborative Modeling Lessons for Environmental Management, Environmental Practice, 9(1), 28-41, 2007.

Cockerill, K.C., H. Passell, and V.C. Tidwell, V.C., Cooperative modeling: Building bridges between science and the public, Journal of American Water Resources Association, 457-471, April 2006.

Tidwell, V.C., H.D. Passell, S.H. Conrad, and R.P. Thomas, System dynamics modeling for community-based water planning: An application to the Middle Rio Grande, Journal of Aquatic Sciences, 66,357-372, 2004.

Cockerill, Kristan, Vincent Tidwell, and Howard Passell. Assessing Public Perceptions of Computer-Based Models. Environmental Management, 34(5): 609-619, 2004.