Significant enhancements to URGWOM have been completed recently. The new 2013 single master model was completed along with the single database file. Two parallel tracks continue with respect to the development of watershed models. The calibration for the Middle Valley portion of the model is close to being completed. Significant progress has been completed for the Lower Rio Grande and Colorado portions of the model.
A new single master model was designed by the Technical Team and was used as the 2013 Accounting Model. It was configured to simplify model maintenance and allow for more efficient use of URGWOM for all applications, including Annual Operating Plan (AOP) model runs and planning runs with multiple hydrologic sequences. The new model has been set up for real-time water operations modeling using 7-day evapotranspiration (ET) forecasts from Reclamation’s ET Toolbox and runoff forecasts from the watershed models.
Two parallel tracks continue with respect to the development of watershed models. Work was completed in 2011 to develop hydrologic watershed models that include snow accumulation and melt for the basin for use by the National Weather Service (NWS) West Gulf River Forecasting Center (WGRFC) for providing forecasted flows. NWS has worked to implement the new models into their new Community Hydrologic Prediction System (CHPS) with the first forecasted flows to be provided in 2014. Riverside Technologies, Inc has completed development and calibration of rainfall-runoff methods in a Hydrologic Modeling System (HMS) model for use during the summer/monsoon season and has initiated work to develop and calibrate snowmelt-runoff methods in a HMS model for use during winter/spring. The HMS models will use the same basin configuration as the completed NWS model.
The URGWOM Technical Team has completed work on an updated conceptual framework and calibration for the Middle Valley portion of the model. New data, a desire for higher spatial resolution within the surface water reaches, and refined model methods enabled the Technical Team to further improve URGWOM from below Cochiti to Elephant Butte. This rework will simplify model administration, and improve the model run-time and efficiency for completing simulations. Enhancements include refinements to the methodology for computing crop evapotranspiration (ET) rates, a new method for representing evaporation losses from wetted sands on the river bed, and changes to the model approach for including crop consumption. These enhancements simplify model maintenance, allow for longer-term model runs of up to 50 years, and increase the efficiency of model runs. The enhanced conceptualization of the Middle Valley includes separate modeling of irrigation conveyance infrastructure on each side of the river, an updated representation for modeling returns to the river at outfalls and wasteways from the Middle Rio Grande Conservancy District (MRGCD) distribution system. Numerous hydraulic conductivities are being reviewed and adjusted for the modeled groundwater fluxes throughout the Middle Rio Grande Valley of New Mexico.
An updated vegetated area survey was completed in 2011 by the New Mexico Interstate Stream Commission (ISC) for updating the URGWOM database to include the latest actual irrigated areas. The survey data was processed for input into URGWOM. The work includes crop survey data processing to estimate irrigated areas using aerial photos and Quality Assurance/Quality Control (QA/QC) activities. Crop areas for each groundwater reach in URGWOM will then be developed. Work is also being completed to develop estimates of actual crop ET as needed for the URGWOM database. Currently, actual ET is estimated as 80 percent of the computed potential ET.
A full update to the URGWOM database was completed in September 2013. Data needed for URGWOM were set up in a new single database file and work began to utilize a new RiverWare data management interface (DMI) dialog to set up new DMIs in URGWOM for importing needed data for simulations from the single database file. Also, numerous enhancements were implemented to the RiverWare rule policy language (RPL) used in the URGWOM ruleset to represent the latest policy for setting diversions, deliveries, and reservoir releases; and to simplify the rules and consolidate the amount of code used to represent policy.
Lower Rio Grande & Colorado Portions of Model
Significant progress has been made on model development for the Lower Valley portion of URGWOM to represent all the key physical processes and include greater detail of the physical system. The Lower Rio Grande surface water model simulates the Rio Grande basin between San Marcial, New Mexico to Hudspeth County, Texas. Further development and refinement of the model will provide additional refinements to physical and rule representations and will lead to incorporation with the Middle Valley portion of the model.
Significant work was also completed to develop a test model for the Colorado portion of the basin. The Colorado test model was set up to simulate the delivery of available water to adjudicated water rights holders, as actually done in Colorado, and with consideration for curtailments to the allocatable flow to assure Compact deliveries are made. Currently URGWOM uses gaged flows of the Rio Grande near Lobatos as an upstream input rather than modeling Colorado water management operations, so the new model for the Colorado portion of the basin was developed to refine the input flows at Lobatos for AOP model runs and planning studies.
A water quality component is currently being developed and will be useful for making management decisions to maintain optimal river ecosystem health while meeting downstream water delivery requirements. The design and incorporation of needed capabilities for simulating water quality into RiverWare has been completed. Currently, the Technical Team is testing the development of the water quality methods and implementing them into URGWOM.
Monthly Timestep PowerSim Model
The URGWOM Technical Team is continuing to utilize a monthly timestep PowerSim model known as the Upper Rio Grande Simulation Model (URGSiM). URGSiM, which was developed at Sandia National Laboratories, has been supported as part of the URGWOM suite of tools since 2006. URGSiM extends from the Rio Grande headwaters to below Caballo Reservoir and includes the San - Juan Chama Project and the Chama and Jemez river systems. URGSiM includes standalone regional groundwater models that interact dynamically with the river and riparian corridor from the Chama – Rio Grande confluence to below San Marcial. URGSiM can be used to quickly evaluate the impact of broad changes in the Basin and is well suited to analysis where many model runs are required. URGSiM was used to run a thousand 100-year synthetic sequences to evaluate how the system might behave under climatic conditions represented by 600 years of tree ring data. URGSiM has also been used to evaluate potential climate change impacts in the basin. A full report on the tree ring based stochastic analysis can be accessed with the first link below and all needed files for a demo URGSiM model can be accessed using the second link:
Stochastic Hydrologic Analysis of the Upper Rio Grande Surface Water System