Colorado – Big Thompson Decision Support System (BIGTDSS)

The Big Thompson Decision Support System (BIGTDSS) was developed by Riverside Technology, inc. (RTi) for the Loveland Water and Power Department, the Greeley Water and Sewer Department, and the Northern Colorado Water Conservancy District. The BIGTDSS was designed with the primary goal of assisting water resources planning and management activities. The decision support system is an integrated configuration of historic and synthetic data, a simulation model representing the Big Thompson water resources system, and several auxiliary analysis tools. The inherent flexibility of the database tools and water allocation model provide the means for gaining insight into the river system’s response to changing conditions. A wide array of water supply-demand scenarios can be created, simulated, and analyzed with the BIGTDSS.

The surface water simulation component of the BIGTDSS is the MODSIM river basin network flow model. The natural, structural, and operational characteristics of the basin have been represented in MODSIM. The model is data driven, with primary inputs defined by monthly inflows and demands. Water is allocated according to the Prior Appropriation Doctrine and distribution is constrained by structural limitations, such as headgate and reservoir capacities. All major agricultural and municipal systems have been depicted and their associated water rights are explicitly modeled.

The DSS can be used to create, simulate, and evaluate a wide range of planning alternatives. Examples of possible applications are:

• Estimating firm yields for individual water resource systems under the representative 50-year and 100-year drought hydrology.
• Evaluating the feasibility of various planning and development scenarios, such as reservoir enlargements.
• Quantifying the yields for particular water rights during wet/average/dry years.
• Evaluating the effects of increased/decreased South Platte administrative calls or possible variations in C-BT operations, such as constant quotas or different carry-over policies.
• Quantifying un-appropriated flows at various locations along the river.

The Big Thompson Decision Support System as displayed by MODSIM

2290 East Prospect Road, Suite 1, Fort Collins, Colorado 80525
phone: (970) 484–7573  fax: (970) 484–7593 www.riverside.com