River Basin Management
Operating Rule Development
Like timing traffic lights to alleviate congestion, effective operating rules can provide substantial benefits -- including increased water supply reliability, hydropower revenue, and ecological flows-- without requiring costly infrastructure changes.
With support from the Water Research Foundation, HydroLogics led a project to produce a guide to effective reservoir operations development, which includes rule forms that address different management objectives and step-by-step guidelines for developing effective rules. Operations development is not a cookie-cutter process; it is a blend of art and science that requires an understanding of the system-specific physical characteristics, hydrology, and management objectives. The guide provides potential rule forms and examples to inform the development process.
The framework for operations development consists of four steps:
Identify long term management objectives, which generally fall into one of the following categories: (a) hydrologic reliability; (b) cost, financial stability, and administration;
(c) environmental performance; (d) recreation; (e) aesthetics; (f) flood control; (g) hydropower; and (h) navigation.
Create displays that allow water managers and other stakeholders to compare alternative operating strategies with regard to one or more management objectives, called performance measures.
Develop operating rule forms. Potentially effective rule forms are best informed by the management objectives and system-specific characteristics. Examples of operating rules in other basins with similar management objectives and/or system-specific characteristics can provide a starting-point.
Select the rule forms and their parameters by comparing simulated alternative operations using performance measure displays.
Our Water Research Foundation project also included case studies of the benefits of improved reservoir operations under challenging climate conditions and practical guidance to utilities to decide if and how to implement more dynamic reservoir operations. Dynamic Reservoir Operations (DRO) are operating rules that change based on the present state of a system, such as storage levels, current inflows, and/or forecasted conditions.
The report demonstrated improved performance over more static operations for both water supply and non-water supply objectives for climate-adjusted and historical hydrologies. While utilities were not able to meet all objectives under extreme conditions without making some undesirable tradeoffs, improved operations will be invaluable for bridging the gap between current and future infrastructure.
Improved reservoir operations is considered a “No Regrets" option by the U.S. Environmental Protection Agency under its Climate Ready Water Utilities program. Regardless of future climate conditions, the investment in developing effective rules is significantly lower than that for capital improvements, and immediate benefits are likely, including a greater understanding of the system.
As an additional step in the refinement in operating rules, HydroLogics has successfully implemented a "genetic algorithm" (GA) wrapper for the OASIS model. The GA wrapper enables automated searches for improved parameters and forms of operating rules, thereby freeing up potentially significant manual trial and error. GAs work by combining and recombining parameters and rule forms from the best of previously evaluated alternatives in a way that is similar to selective breeding. The wrapper uses an Excel interface to structure the search and can use either the Frontline solver for Excel or HydroLogics internally-developed parallel processing GA. The GA wrapper has been used to improve simulated operating policies for the Apalachicola-Chattahoochee-Flint Basin in Georgia, Alabama and Florida and for Lakes Rotorua and Rotoiti in New Zealand.
Click on the publication below for our article on the benefits of dynamic operating rules.