Real time control - informing political decision making

This paper discusses the application of the North Shore City Council’s (NSCC) calibrated trunk wastewater model to assess the performance of the NSCC Real Time Control scheme and the use of the model to develop a range of RTC operational scenarios to achieve differing objectives i.e. minimise spill frequency, minimise spill volume or control of spills to preferential locations.

The NSCC trunk sewer model and RTC scheme were developed as part of the Project CARE Review study, which was an update and extension of an existing strategic wastewater model to aid in infrastructure planning. The current operation of the NSCC wastewater network includes the control of number of gates and pumps to minimise spill volumes and to preferentially spill at certain locations. MOUSE User Written Controls (UWC) were developed to simulate these controls appropriately. The UWC module deals with local PLC operations and remote SCADA operations of the control structures. The implemented control logic ranges from simple gate operations to more complex storage synchronization.

NSCC’s RTC provides flexibility in how the system is operated. Model analysis of the NSCC’s RTC operation informed a clear understanding of the RTC’s operational flexibility and potential impact on system performance. However with that flexibility comes choice, requiring political decisions to be made in the selection of the preferred operational strategy.

This paper briefly outlines the development of the model RTC, and discusses the option assessment performed on the RTC scheme to develop a range of operational RTC scenarios and the implications of these schemes to network performance.