Evaluating the Speed and Design of Paris 2024 Olympic Pool

Aquatics experts at Counsilman-Hunsaker respond to complaints that the Paris Olympic pools are slow, hindering athletes' performance.

Originally published by Aquatics International on July 31, 2024.

We have been fielding many inquiries regarding the perception that the Paris 2024 Olympic competition pool is a “slow pool.”

As an industry expert in aquatic consulting and engineering, Counsilman-Hunsaker has extensive experience in the design of swimming pools utilized for the highest level of swimming competition. Our firm has designed hundreds of long-course competition pools and collaborated with the manufacturer of the Paris Olympic competition pool, Myrtha Pools, on many successful projects. Our experience in pool design consultation for major swimming competition events such as the 1996 Atlanta Olympics, 2012 London Olympics, and the 2021 and 2024 US Olympic Trials provides us with a unique perspective on the ongoing debate regarding the depth of the 2024 Olympic swimming pool in Paris.

While our firm did not consult on the Paris Olympic installation, we offer the following insights as observations for discussion.

Background

The preferred water depth for competitive swimming pools designed to host competition swimming events as prestigious as the Olympics is generally 3 meters. This standard has been established with the intent to minimize turbulence and enhance swimmer performance. The decision by the Paris 2024 organizers to construct the competition pool with a depth of 2.15 meters has led to some recent criticism in the media.

When the Paris pool design was permitted, the World Aquatics minimum depth requirement for Olympic competition swimming was 2.0 meters. Although the World Aquatics facilities standards recommend a depth of 3.0 meters, this recommendation is often tied to multi-discipline use, such as Artistic Swimming. Since the time that the Paris installation was permitted, World Aquatics has increased the minimum depth requirement for Olympic competition to 2.5 meters.

Scientific speed vs. visual perception

Understanding the interplay between scientific speed and visual perception is crucial in evaluating the impact of pool depth. Scientifically, deeper pools are considered faster due to reduced underwater energy rebound causing turbulence. When waves hit the bottom of a deeper pool, they do not rebound as strongly, resulting in a smoother swimming environment. This reduction in turbulence can enhance swimmer speed, providing a tangible advantage in competitive settings.

However, the psychological aspect of swimming in deeper pools cannot be overlooked. When swimmers see the bottom of the pool further away, it can create a perception of slower movement, potentially affecting their performance. Balancing these scientific and psychological factors is essential in designing a pool that optimizes both speed and swimmer confidence.

Diminishing returns of depth

While deeper water is certainly considered better and faster for peak competition swimming performance, there is a point of diminishing return at which the effect of additional depth becomes negligible concerning the rebound of energy through the water from the pool floor. Historical research indicates that underwater wave energy from a swimmer’s cone of influence is immeasurable at distances beyond approximately 6 feet from the swimmer’s body. However, as swimming techniques have evolved, with swimmers spending more of the race underwater and closer to the pool floor, this factor may be more significant than in the past. A final factor to consider is the large amounts of cameras, tracks, and broadcasting equipment placed on the pool floor. This equipment may be within the swimmers' zone of influence as they swim underwater off of dives and turns.

Case studies

The University of Minnesota's pool exemplifies how depth variations can still yield high performance. This pool, with depths ranging from 7 feet to 7 feet 10 inches, has been the site of numerous record-breaking performances, including Caeleb Dressel’s remarkable 17.63-second 50-yard freestyle. Despite not meeting the 3-meter depth standard, this pool's design demonstrates that high-caliber performances are achievable in slightly shallower pools. This challenges the notion that only 3-meter-deep pools can be considered "fast" and underscores the importance of other design factors in creating optimal swimming conditions.

Similarly, the actual water depth of the US Olympic Trials pool installed this year for the event this year in Lucas Oil Stadium was 8 feet 3 inches, and the Australian team trials were hosted in a pool only 2.0 meters deep. Fast times and world records were set at both US and Australian trials meets. These examples further illustrate that not all "fast pools" are 3 meters deep and that depth alone does not determine pool speed.

Recent developments and standards

Recent updates in World Aquatics guidelines have raised the minimum pool depth for Olympic Games to 2.5 meters. This change reflects a growing recognition of the need to balance various factors influencing pool performance. While the new standard is still below the 3-meter preference, it represents a step towards addressing concerns about turbulence and swimmer speed.

The decision to set the Paris pool depth at 2.15 meters falls short of even the revised minimum. This deviation from established practice from past Olympic venues has fueled the debate and scrutiny surrounding the pool's potential impact on athlete performance. However, it is essential to consider that once pool depths reach approximately 2 meters, the incremental speed benefits have diminishing returns, and are marginal when compared to other secondary performance factors such as tech suits or shaving.

Athlete welfare and performance factors

Beyond pool depth, athlete welfare plays a critical role in determining performance outcomes. Living conditions, nutrition, and environmental comfort significantly impact athletes' preparation and performance on race day. Reports of inadequate food supplies and teams bringing their own air conditioning units to the athlete village highlight concerns that extend beyond the pool itself. In addition, the long transit times from the Olympic Village to the pool (and vice versa) are taking their toll on athletes. More transit time means less time that the athletes have for recovery between sessions.

Ensuring that athletes have access to optimal living conditions is paramount. Poor living conditions can undermine performance, regardless of the pool’s design. Addressing these issues is vital to providing a holistic approach to athlete support, ultimately enhancing performance and overall well-being.

Recommendations for future pool design

To further optimize competitive swimming conditions, several recommendations can be made. First, adopting double lane-lines, as practiced by the NCAA, could be beneficial. Double lane-lines reduce wave interference between lanes, creating a smoother swimming environment and potentially enhancing performance. Additionally, reconsidering the design of end walls and touch pads is crucial. Tall end walls and touch pads cause significant water to rebound, disrupting the pool's flow and creating turbulence. Incorporating gutters and water-level touchpads at the end walls can help absorb waves as swimmers make turns, maintaining a smoother environment.

While depth remains a critical factor, these additional design considerations can collectively contribute to creating faster and more conducive competitive swimming environments.

Other pool and natatorium design considerations

Other considerations must be taken into account when optimizing a facility for peak performance. Air quality is a crucial concern that is often overlooked. Chloramines must be quickly and effectively removed from the natatorium environment to ensure that athletes can breathe deeply and easily on meet-day. Water temperature starts to play an increasingly important role as the distance of swimming events get longer. 78 to 82 degrees Fahrenheit is the window for World Aquatics swimming competition, with the low end of that range being preferred. Starting blocks must be considered and are especially crucial in shorter races; blocks with a track-start wedge and hand grips are ideal for providing a fast start.

Conclusion

The debate surrounding the depth of the 2024 Paris Olympic swimming pool highlights the complexities involved in optimizing competitive swimming conditions. Balancing scientific insights on turbulence reduction with the psychological effects of depth perception is essential in creating pools that enhance performance. Case studies such as the University of Minnesota's pool demonstrate that high-caliber performances are achievable in slightly shallower pools, challenging the notion that only 3-meter-deep pools are "fast."

Recent updates to World Aquatics guidelines represent progress in addressing these concerns, but the Paris pool’s 2.15-meter depth has fueled ongoing controversy. Beyond pool design, athlete welfare and living conditions significantly impact performance outcomes and should be prioritized.

In future pool designs, adopting practices such as double lane-lines and reconsidering end wall designs can further optimize competitive swimming conditions. By considering these factors holistically, we can create environments that not only enhance speed but also support athletes’ well-being and performance.

Meet the Authors:

Kevin Post - In the role of Chairman and CEO, Kevin Post leads Counsilman-Hunsaker’s executive team and leadership. With over 20 years of experience in the aquatic industry, Kevin has served a variety of client types including public and private clubs and waterparks, municipalities, universities, YMCAs, and school districts. As CEO, Kevin aims to strengthen Counsilman-Hunsaker's position as the industry leader, speaking at national conferences and major universities, and educating the industry on sustainable business practices for pools, new technologies for aquatic facilities, and the science behind risk management.

Kevin Post has been recognized in Aquatics International’s 2019 Power Issue for his efforts in making pools safer and more sustainable and again in 2021 for leading Counsilman-Hunsaker’s COVID-19 response efforts. Kevin is a contributing author to WWA’s annual development guide and The Complete Swimming Pool Guide. Kevin also serves on the Board of Directors for the Pool and Hot Tub Alliance (PHTA) and the Council for the Model Aquatic Health Code (CMAHC). He also serves as Vice-Chair for the PHTA-11 and PHTA-16 standards writing committees and as the board liaison for the PHTA Commercial Council and the CPO Advisory Committee.

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Darren Bevard, P.E. - In Darren's role as President and Chief Operating Officer, he leads the design and engineering teams and the processes driving Counsilman-Hunsaker's efficiency. He possesses a wealth of experience in designing aquatic facilities to serve a variety of user groups providing practical, cost-effective, and efficient designs. Darren holds a Bachelor of Science degree in mechanical engineering from the University of Memphis where he graduated Summa Cum Laude with university honors and honors in mechanical engineering. He is currently registered as a professional engineer in seven states.

Darren Bevard can frequently be found speaking at various industry symposiums often highlighting efficiencies in aquatic facility operations and the latest advancements in technology being utilized in commercial aquatic design. He was recently honored in the Aquatics International 2020 Power Issue as an aquatics industry influencer through his focused work in the Southern region of the United States.

Darren’s free time is enjoyed with his wife and three children, spending time outdoors – boating, fishing, soccer, swimming, snowboarding, hiking, hunting, camping – and especially watching his kids play sports!

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Cole Henry P.E. - Cole utilizes passion, professional experience, and his engineering education to deliver exceptional solutions to clients and end-users. Cole began swimming in high school for the nationally recognized Scottsdale Aquatic Club. He attended Colorado School of Mines starting in the fall of 2013. During his four years at School of Mines, Cole was a member of the varsity swim team and was team captain during his Junior and Senior year. Cole graduated Cum Laude from School of Mines in 2017 with a Bachelor of Science in Mechanical Engineering.

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Robert "Bo" Ilgenfritz P.E. - Robert graduated Cum Laude with a Bachelor of Science in Aeronautical and Astronautical Engineering and a minor in Computer Graphic Technology in 2016 from Purdue University. Following graduation, he worked for five years in the aerospace industry as a design engineer for Northrop Grumman, supporting military aircraft design, and as a propelling systems engineer for United Launch Alliance, supporting the upper stage of the Vulcan Centaur launch system.

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Maddie Monroe - As a project manager in the Northeast studio, Maddie oversees the day-to-day operations of projects from their inception through construction. Her responsibilities include meeting with end users to establish program needs, coordinating with CH staff and clients to provide quality construction documents, and working with contractors through the construction administration phase of the project. Additionally, Maddie plays an integral role in ensuring industry-leading construction documents by serving as a leader in the quality control process, ensuring CH is at the forefront of design.

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Daniel Borgatti -Hailing from Belo Horizonte, Brazil, Daniel moved to Florida during the latter half of high school. After graduation, he went to Purdue University where he obtained his bachelor's degree in Mechanical Engineering and a master's degree in Engineering Management.

Having swam competitively and teaching in the Learn to Swim program at Purdue, Counsilman-Hunsaker allows Daniel to combine his passion for the sport and engineering and help fulfil his desire to become a certified Professional Engineer.

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