City of Granbury Hydraulic Water Modeling Analysis

CLIENT: City of Granbury
LOCATION: Granbury, TX

eHT developed a hydraulic computer model for the City of Granbury with Innovyze’s H2OMap Water GIS Suite 8.0 to identify the water distribution system improvements needed to compliment the City’s Water Treatment Plant (WTP) Expansion, identify the water distribution system improvements needed once the City’s wholesale water supply agreement ends, and to identify low-pressure areas or deficiencies in the water distribution system.  The hydraulic model was developed based on available water distribution system maps, approximately 13 years of “as-built” construction plans, and operational data provided by City Staff and field survey data.

Information provided by the City indicated a total of approximately 5,700 service connections on the system. Historical water use data was used to develop Average Day Demands and Peak Day Demands for the model, in addition to the Texas Commission on Environmental Quality (TCEQ) peak hour demand of 1.50 gpm/conn.  The actual operational settings for the pumps and tanks were incorporated into the model for greater accuracy. These settings included water surface elevations in the tanks, manufacturer pump curve information, and the pump on/pump off settings currently programmed into the system, and accounted for different operations during average and peak day demand scenarios.

The modeling observations indicated that significant distribution system improvements were needed to adequately convey the increased WTP capacity throughout the system, to maintain service to the East Pressure Plane after the conclusion of the City’s wholesale water supply agreement lapses, and to allow proper interaction between the City’s existing storage facilities.  In addition, the model identified a few areas in the system that were experiencing low pressure issues during peak demand periods.  The modeling results were the basis for the City’s Water Distribution System Improvements Project which includes approximately 22,000 linear feet of new 16” PVC water line, 12,000 linear feet of new 20” PVC water line, a new 0.25 MG elevated storage tank, a new booster pump station, multiple control valves throughout the system, and other miscellaneous system improvements.