Modern Computer Analysis for Developing New Methods of Surge Control to Replace a Problematic Surge Protection System

This paper presents a comprehensive hydraulic transient analysis, performed using the latest computer modeling programs, for evaluating three pump stations and the connected raw water transmission main system, originally designed for surge control utilizing hand calculations. The Waurika Lake Master Conservancy District (WLMCD) provides raw water to the cities of Lawton and Duncan, Oklahoma from Waurika Lake via three pump stations. These stations are: 1) Waurika Lake Station; 2) Lawton Relift Station; and 3) Duncan Relift station. WLMCD was concerned about the adequacy and reliability of the aging infrastructure and existing surge protection systems due to sticking surge anticipator valves at the pump stations and excessive transient waves causing issues in the pumping and transmission system over time. WLMCD initiated a project to study and develop recommendations to address these concerns. The project consisted of analyzing the system facilities -including pumping, piping, and related appurtenances - for potentially damaging levels of surge and providing recommendations to help protect the system more effectively. The original 1970's design of the Lawton and Duncan systems used hand calculations to evaluate and configure surge control systems using best practices available at that time for selecting, sizing, and locating equipment and controls. Over time, improved tools such as sophisticated computer modeling programs were developed to help analyze, refine, and devise functional solutions for surge problems. This project was intended to take advantage of these new analysis tools to refine surge protection systems that were originally designed more than 30 years ago.