Texas-Style Redesign of a 20-Year-Old, 104 MGD Flow Control Facility

Black & Veatch is currently leading the engineering design services for a capacity expansion of the Doe Branch Discharge (DBD) facility for the city of Irving, Texas. These services include hydraulic design, transient analysis, selection of flow control valves, commissioning, testing, and calibration of the improved facility. Jim Chapman Lake, in Texas, is one of the primary water supplies for the city of Irving (Irving). Irving owns and operates a large water supply system in partnership with the North Texas Municipal Water District. The 100-mi, 72 and 84-in. raw pipeline conveys water from Jim Chapman Lake to both Lavon and Lewisville Lakes. Irving’s portion of the water is discharged into Doe Branch Creek through a flow control facility and stilling basin located in Prosper, Texas, just upstream of Lake Lewisville. The DBD facility is hydraulically controlled by a ground storage tank located in Prosper, Texas. Because everything is or gets bigger in Texas, up to 104 million gallons per day (MGD) are anticipated to be discharged in the summer of 2025 through this 20-year-old facility due to current expansion of the Lake Chapman Conveyance system, which will also receive and transfer up to 55 MGD to Lake Lewisville in 2025 from the Upper Trinity Water District’s Lake Ralph Hall Project. Black & Veatch is currently leading the engineering design services for rehabilitation and expansion of the DBD facility. This paper provides details on Irving’s capacity expansion needs and O&M requirements, identifies the methodology and models developed for the analysis, and summarizes the findings and recommendations which include removing the only flow control valve currently in the facility (42-in. sleeve valve—20+ year-old and partially operational) and adding two trains of 36-in. multiple orifice valves (MOV) inside the existing 20-year-old valve vault. Each 36-in. train includes upstream and downstream isolation butterfly valves and a dual configuration of MOVs to handle the large range of water flow rates and maintain pressures the system requires.