Credit: EID

With geospatial time series management, El Dorado (Calif.) Irrigation District information support technician III Timothy Hance, left, and Guy Barritt, GIS/drafting/graphics unit supervisor, could forecast and model trends in drinking water supplies over their entire watershed.

Credit: EID

For an agency with multiple responsibilities, such as managing drinking water supplies and providing hydro-electric power generation and recreation functions, GTSM could help manage demands and temporarily shift resources to hot spots, such as EID's 21 MW powerhouse.

If an agency has GIS in place, GTSM can be designed and operating in a few months. The value of the transition to GTSM will be apparent in even less time. Agencies that have purchased data collection and mapping programs finally will see their original investments transformed into true decision-making tools. Such a practical, cost-effective outcome puts GTSM on the fast track to becoming a standard tool for public works and other agencies.

— Wodraska is national director of water resources for the West Palm Beach office of PBS&J; Hampson is water resources technology program manager for the firm's Tampa office.

Managing water supplies

Water agencies and municipalities are increasingly interested in maximizing the water resources they have. GTSM can help meet water agencies' goals. The technology started as a decision-making tool for water resource management, and its application offers significant advantages to agencies managing water supplies.

By integrating both SCADA operating data and GIS spatial data, GTSM can relate water level readings, collected over time, to the specific size and shape of a selected water body. Integrating these data creates a meaningful picture of the available water storage and capacity trends for use in reservoir management decisions.

GTSM also enhances the use of hydraulic and hydrologic (H&H) modeling programs. Stream flow data can be related to the specific water body under study, including the flow control structures and natural barriers found there. While typical H&H models consider only a peak flow period, which is a single point in the time series, GTSM considers the entire hydrologic curve. This creates a more accurate picture of flow through both natural supply channels and water treatment facilities.

In addition, water network data—levels, flows, rainfall data—can be provided in GIS terms. By packaging data into geospatial time series data, managers can review short-and long-term storage requirements for a region or a particular reservoir and make reliable system-state predictions. Water managers can accurately determine the impacts of moving water resources from one region to another in their service area and prepare water budgets.

The genesis of GTSM

GTSM evolved from the award-winning Arc Hydro Enterprise Database, an application developed by Redlands, Calif.-based ESRI to give the South Florida Water Management District timely, accurate data about South Florida's hydrology for watershed management. The application formed a unique relational database environment in which natural connections between natural water bodies, control structures, monitoring points, and drainage basins are linked to stored time series data. Combining GIS with time series data provided water balancing information, hydroperiod estimates, and other outcomes to the District for water resource and environmental management. The Arc Hydro Geodatabase and Arc Hydro Tools have become the accepted GIS data model for hydrologic information systems nationwide.

GTSM, the next step from Arc Hydro, was developed by consulting firm PBS&J, in collaboration with the University of Texas Center for Research in Water Resources, ESRI, and DHI Water & Environment, Vero Beach, Fla. Picking up where Arc Hydro leaves off, GTSM translates data into a single, accessible GIS-driven resource. Data, such as those collected with SCADA, are integrated into ESRI's Arc Hydro geodatabase, and raw data are converted to the right units and format with a GIS framework. The application gives all team members access to time-varying data instantaneously.