As the world’s population increases and extreme weather events become more commonplace, open channel design is becoming an essential component of the engineer’s water management toolbox.
Surface drainage for new subdivisions, drainage systems for flood mitigation, and stream restoration for improved aesthetics or ecological concerns are common examples of open channel design in the eastern U.S. In the western U.S., moving large amounts of water to population centers and building agricultural irrigation systems are examples of how engineers use open channel design.
“Anyone can rent a skid steer or bulldozer to dig a ditch without any attention to design if one so desires,” said Ernest W. Tollner, a professor in the University of Georgia College of Engineering. “But what if one is tasked with managing the waters belonging to the state to meet the needs of multiple stakeholders? Channels are designed to convey waters in an economical and ecologically sustainable way for the benefit of all stakeholders.”
A new textbook authored by Tollner provides engineering students a solid understanding of open channel design and prepares them for land development and related consulting work. Open Channel Design: Fundamentals and Applications was published recently by Wiley Blackwell.
Solutions in open channel analysis, even the basic one-dimensional solutions, tend to be iterative in nature, Tollner said. His textbook provides a suite of spreadsheets that facilitate the iterative solution process and devotes attention to the “what-if” possibilities worthy of exploring. The book also introduces a public domain software from the U.S. Army Corps of Engineers, HEC-RAS, for natural channel analysis.
“One of the most significant challenges is that open channel designers operate under the reality that man decides how much drainage is needed. At the same time, nature dispenses the rainfall that is to be drained,” said Tollner. “Minimizing land required for drainage channels, maintaining the aesthetics and ecology of a region being drained, and providing economically feasible and safe, sustainable designs are other challenges.”
A professor at UGA for more than 40 years, Tollner’s research focus is to discover system descriptions of hydrologic systems with the overall goal of improving water resource management and watershed ecological health. He has published more than 100 studies, written three textbooks, and holds a U.S. patent.
Tollner earned his doctorate in agricultural engineering at Auburn University. He received both his bachelor’s and master’s degrees in agricultural engineering at the University of Kentucky.