Engineers and scientists love graphs. With one image, they can convey as much information as many pages of text and do it in a way that can be clearly visualized. Nowadays, with software, we can do so much more with graphing, but that’s not always the way it was done. Here is how simple graphs used to look like in the past, drawn on preprinted graph. Straight line y=mx+b Here is a graph you can get from Excel today: Sure, anybody can draw a graph on arithmetic graph paper. But what happens when you have data that cover several orders of magnitude and data aren’t very evenly spaced. You could take the logarithm of each point and plot it that way, but then you would need to continuously convert the data from the log scale to your original values. For example, “the graph says 3.52 but that’s the log of the real value that is 3311”. The key of course is to have graph paper with logarithmic scales. Your graph paper would look like this: The figure shows 3 cycle log-log paper. Straight line y = aXb In Excel the figure could look like this: Sometimes, however, only one axis

For academic researchers, “Impact Factors” is a familiar term – it is designed to measure the impact of your publications. If you are outside of the academic world, you have probably never encountered it, but how much do these metrics really tell us? Impact factors emerged as a way to compare research papers. Academia often measures a researcher’s success by the number of publications, which influences tenure and promotion decisions at universities. The problem was that not all journals and papers are of the same quality. Universities needed a way to determine the caliber of research without having to actually read every paper. The solution? If a paper was cited by other researcher within a few years of publication, it is assumed that the paper and the journal it appears in must have an impact. Over time, this has evolved into a formal system for calculating Impact Factors, with journals proudly listing their scores. To judge individual papers, metrics like “categorized-normalized citation impact” were developed using similar logic along with a “percentile group” score to compare a researcher’s work with papers in a similar field. But I question: “impact on whom”? I feel that the impact of a paper in

When precipitation falls on land, in the short term, there are two places it can go: runoff to streams or infiltration into the ground. In the long term, evaporation also matters, but during a precipitation event, it isn’t important. Runoff enables water to be used for a variety of purposes as it makes its way to the ocean. Along the way, however, it contributes to flooding, erosion, and is usually moving too fast to be captured. From an environmental and water efficiency standpoint, it is generally better to have most of the water infiltrate into the ground, reducing flooding, nurturing plant life, and later contributing to base flow in streams, flattening out runoff hydrographs. But first, a digression that always troubles me: “What is infiltration?” There are at least two answers: In hydrology and some hydraulics, infiltration is the precipitation that makes its way into the ground. However, if you’re talking about sewers, infiltration is a subsurface water that leaks into sewers when it shouldn’t (i.e., the I part of I&I). The first infiltration is generally a good thing; the second is a bad thing. The result is sentences like “Infiltration into the subsurface can result in additional infiltration into

Cities and towns often rely on local consultants to provide them with water, wastewater, and stormwater modeling. By bringing modeling efforts in house, municipalities can benefit from: Saving Money Often, even the smallest projects can come with a hefty price tag. By using in-house professionals, municipalities can save the money typically spent on consulting and use it toward capital improvements. Improved Reactions to Emergency Situations When a city handles its own model and has an in-house expert, they can more efficiently respond to emergency situations without having to wait for consultant analysis. This situation also holds true for leak detections, helping to reduce lost water. Model Consistency Many municipalities have a bunch of smaller, separated models. By combining these smaller models into one large model, the entire system can be analyzed. This combined model also creates a baseline for expectations of how modeling can be done in the municipality. System Efficiency As municipalities begin to explore capital improvements, they can leverage their system model to determine the most cost-effective path forward. From an operational standpoint, cities can also ensure they are making the most of their system. Getting up and running with new software is less daunting than a city

Seminal papers are groundbreaking at the time of publication and remain influential many years later. I recently received word from the ASCE that my paper, “Battle of the Network Models: Epilogue,” published in the Journal of Water Resources Planning and Management, Volume 113, No. 2, 1987, has been selected to receive the Journal’s 2024 Seminal Paper Award. Here’s the story behind it if you are interested. In the early 1980s, many papers were being published on optimal pipe sizing in water distribution systems. It was hard to compare the methods. At that time, there was a television show, “Battle of the Network Stars,” where various TV stars would compete with one another in various little “athletic” events. The show ran from 1976 through 1988. I thought that would be a good name for a conference session and paper that I called “Battle of the Network Models.” I drew up a pipe network called “Anytown” and sent it out to everyone working in this area. We had a series of sessions at the ASCE Water Resources Planning and Management Conference in Buffalo, New York, in 1985 that brought together many of the top people in the field. I wrote the summary

Back in the dark ages (e.g., the 1980s) before everyone had video capabilities on their cell phones, creating a training video was a big production. Video cameras (and their batteries) weighed about 30 pounds and editing tools we crude. I was doing a lot of flow testing in those days while working for the Army Corps of Engineers at the Waterways Experiment Station (WES) in Vicksburg, Mississippi. I had some money available and wanted to capture not only the mechanics of flow testing, but how to use the results of such tests in modelling. I didn’t want this to be a boring video with me as a talking head with a shot of a flow test. This was also a at that time, MTV was becoming very popular (Remember when MTV played videos? At least I hope some of you do.), so I wanted to use a lot of short scenes interlaced with music (and perhaps a little humor). This is how I became the writer, producer, director, and narrator for a training video on hydrant flow tests. I was shooting for something like historian James Burke’s “Connections” series for engineers. https://en.wikipedia.org/wiki/Connections_(British_TV_series) The video production came down to a couple

AWWA recently announced the release of the fourth edition of its popular manual, M22-Sizing Service Lines and Meters. You might be thinking, “What could be new in sizing service lines?” For the most part, not much has changed, but there has been a major update to the way that residential peak demand is calculated. If you only have a single fixture in a building, then the peak demand in the building is the same as for the single fixture. If you have two fixtures, just add the demands. As the number of fixtures increases, however, the chance that all will be running at the same time decreases. This problem was solved nearly a century ago by Roy B. Hunter of the National Bureau of Standards (Hunter 1940, 1941) who developed an expedient method based on the Binomial theorem and flows from typical water fixtures from the 1930s. The result was the widely used Hunter’s Curves that related the peak water demands to the number of fixture units. The iconic Hunter’s Curve worked so well that it was quickly incorporated into many plumbing codes around the world. Over the years, however, the Hunter’s fixture unit concept has been modified by various

The term given to this process is “Daylighting” (although the term gets used in a lot of other situations). The American Rivers organization is one of the leading groups in the U.S. that promotes stream daylighting. Their definition is, “Stream daylighting revitalizes streams by uncovering some or all of a previously covered river, stream, or stormwater drainage.