Hydraulic transients cause low‐pressure problems

Mysterious short‐term pressure drops at the top of Cat Mountain prompted an investigation that revealed hydraulic transients as the culprit. Most engineers are familiar with hydraulic transients that cause problems with excessive pressure in water distribution systems. However, transients can also cause short‐lived low‐pressure problems. This article describes the analysis conducted by the Austin (Texas) Water and Wastewater Utility that identified transients as the source of low pressures in a portion of the city. Pressures recorded during controlled conditions provided the key in identifying pump and valve operation as the source of the problem.